Author Archives: the short coat

09.06.12
by

Never Trust Your Patient(‘s Med List)

The Gist:  In addition to physician-borne cognitive errors, patients and the system may contribute to medical errors/misdiagnosis in the ED due to unreliable and incomplete medication histories.  The ED patient may be more likely to experience these errors because:  trauma patients generally don't update their medication lists and ensure it's readily accessible prior to getting into a motor vehicle accident or stabbing, critically ill patients often can't communicate well, access to patient information across multiple databases is insufficient (the ED attracts patients who are away from home or at hours when pharmacies/physician offices are closed), etc.  Second guess medication lists.  Take a better medication history, even if there's one listed on the chart, and assume the patient is on medications that you don't know about (I have no evidence for the latter statement other than the fact that omission errors in medication lists are the most common).  There's a great, free full text article by FitzGerald in the British Journal of Clinical Pharmacology that summarizes this problem nicely.  

The case:  A 52 year old female presented with syncope.  She had an episode of syncope and several episodes of near syncope over the prior day.  Overall, she complained of not feeling well.  The patient's vital signs were significant for a blood pressure of 82/50 and a pulse of 58.  Her symptoms worsened when she stood or moved abruptly, which she hasn't been doing much of because she feels terrible.  No other positives on history or physical.  She had a PMH of hypertension (on 3 medications per medical record/history) and diabetes (glucose 125 on metformin).  Patient's IVC had <30% respiratory variation on ultrasound and ECG showed sinus bradycardia and no other changes.

Diagnosis:  Iatrogenic hypotension and bradycardia secondary to anti-hypertensives.  

Outcome:  Patient's blood pressure was stablized and her medications were reviewed and decreased to two anti-hypertensives at relatively small doses.  She was seen for follow-up by her PCP 4 days after hospital discharge, still feeling "weak."  Her blood pressure and pulse were both still low, 90/64 and 58 beats per minute.  In addition to the medications the patient was supposed to be on: metformin, losartan/hydrochlorothiazide, and atenolol, the patient's medication bag contained the following (all blood pressure pills, three of which were beta-blockers):
Apparently, when doses were changed, she filled the new script and added it to what she had at home.  The patient didn't have great medical literacy, a learning point for when we give verbal or written instructions (hence the bottles labeled "STOP" that were then covered with tape).  

The paper:  This month's American Journal of Emergency Medicine has an article, How reliable are patient-completed medication reconciliation forms compared with pharmacy lists?, describing how inaccurate medication reconciliation forms are in the ED setting.  This is not the first study demonstrating the incredible error rates in patient medication lists.
  • Prospective study using a convenience sample
  • Patient completed medication reconciliation forms and a research assistant tracked down information from patient pharmacies that covered the preceding 3 months
  • 484 eligible, n=315 with complete data sets opted to enroll.
  • 33 % (n=104) had errors of omission, 12.7% (n=40) had errors of addition, and 18.1% (n=57) had both types of errors
The scope of the problem:  
  • In one study, 78% (n=637) of ED medication histories were inaccurate.  This has been corroborated by multiple other studies, summarized in this systematic review (full text).   
  • Most susceptible populations:  individuals with extensive medication lists, minimal health literacy, and limited communication capacity
Ways theses errors cause problems:
  • Hypersensitivity/Allergic Reactions
  • Cause of patient's ailment
    • Directly due to drug.  ex:  NSAIDs/ASA/anti-platelet agents/warfarin - bleeding; diuretics - acute kidney insufficiency
    • Polypharmacy.  ex: anticholinergic toxicity from multiple medications which could be detected via a complete medication list
    • Narrow therapeutic index.  ex:  phenytoin, lithium, digoxin
  • Masking signs or symptoms of illness
    • Ex:  Beta-blockers or anti-pyretics
  • As the case above demonstrated, it's not only important to know a patient's medication list, but precisely how the patient is actually taking the medications.  
    Solutions  Note: Most papers are targeted at the inpatient services, but a few have targeted the ED to improve medication history accuracy.
    • Review patient's medications verbally.  This is still largely inaccurate as demonstrated by the aforementioned study, although apparently better than reading from a patient's list.  
    • Assume that the patient is on medications that are not reflected in their medication list/history.  
      • When I see a large, swollen lip I presume the patient is on an ACE-I until proven otherwise.  If they have no idea, my assumption doesn't change initial management (airway, airway, airway, and the anaphylaxis cocktail) but it will cause me to pursue whether or not the patient is on an ACE-I and whether or not I get in touch with their PCP.  All too often, the patient eventually remembers being on a pill for years for blood pressure that ends in "-pril" or a family member brings in the offending bottle of pills.
    • Careful attention to the ways we obtain medication lists. A RCT by DeWinter et al (n=260) showed that having EPs ask specific medication history questions can significantly reduce ommision errors, which seem to be the most common in the ED.  In this study, the intervention reduced errors from 1.1 per patient to 0.6 per patient (still pretty high) (2). 
    • Systems-level changes.  These are likely more expensive, time consuming, and difficult to implement than individual changes but certainly an area for future improvement.  In fact, this is likely the area that will need to change the most to truly address the problem.
      • Changes in ED medication reconciliation process that utilizes "waiting" time and are driven by the patient have been proposed.  This BMJ article proposes that patients could organize medications in the waiting room and be provided with a "toolkit" to assemble their medication lists (numbers to reach physician offices, pharmacies, instructions to call home), if needed.  This would be used in line with electronic medical records reconciliations and confirmation by the nurse when the patient is taken to a treatment room (3).  Looks promising but would take some effort to implement (and benefits are not yet proven).
      • Use of pharmacists or technicians within the ED to obtain and confirm medication lists has demonstrated improved accuracy in a few studies, including a small Canadian study that achieved excellent results in obtaining accurate medication histories.  Pharmacists and technicians spent about 8-10 minutes per encounter on the phone with the patient's pharmacy in addition to obtaining medication histories from the patients and electronic medical records (4).  This is a pretty expensive option but if you have them, utilize this resource.
    • Electronic Medical Records.  These have short-comings as well, as patients don't always take the medications as prescribed and often receive medications from multiple providers that may or may not be reflected in the system.  This is certainly one piece to the puzzle, and a benefit in patients who may not be able to communicate (due to trauma, sickness, or baseline deficit). 
    References:
    1.  Mueller SK, Sponsler KC, Kripalani S, Schnipper JL.Hospital based medication reconciliation practices: A systematic Review Arch Intern Med. 2012 Jul 23;172(14):1057-69.
    2.  De Winter S, et al.  A simple tool to improve medication reconciliation in the emergency department. Eur J Int Med.  2011 Aug;22(4):382-5. 
    3.  Hummel J, et al  Qual Saf Health Care.   Medication reconciliation in the emergency department: opportunities for workflow redesign.2010 Dec;19(6):531-5.
    4.  Johnston R, et al.  Best possible medication history in the emergency department: comparing pharmacy technicians and pharmacists.  Can J Hosp Pharm. 2010 Sep-Oct; 63(5): 359-365

    08.30.12
    by

    Anchors Aweigh! Cognitive Bias – Where IS This Ship Headed?

    The Gist:  We all succumb to cognitive errors from time to time.  Identifying these errors in our medical decision making though exercising metacognition may improve patient safety but it may also allow us to be better clinicians.  NB:  This is not a comprehensive review of all types of cognitive biases, which one can find here in "List 1."  Rather, this is a synopsis of some of the commonest cognitive biases, which I've learned from first-hand.

    Anchoring Bias     - when a first impression or one piece of evidence exerts undue influence in the diagnostic process.
    • Case:  Listen to a great new blogger/podcaster, Dr. Bob Stuntz, present a case on Anchoring Bias in which he gives an excellent example of the patient who comes in complaining of "I have a kidney stone."
    • Solution: wait until information about the case is complete before forming an impression or selling yourself on a diagnosis.  Note:  clearly in some critical situations one must act before information is complete.   
    Triage Cueing - bias initiated by the patient's initial triage level, assuming that a patient can't be sicker than their triage level.  
    • Case:  A patient was placed in the "minor care" area for a "sore throat."  The patient's PMH included hypertension and the history elucidated that the patient's complaint was more of a dry throat (drinking copious amounts of water) coupled with a yeast infection that wouldn't go away.  She also generally felt terrible and weak.  The attending was initially wary of the idea of a fingerstick glucose level but acquiesced after discussing that polydipsia and intractable yeast infections are harbingers of uncontrolled diabetes.  The result = 587 mg/dL.  Chemistry demonstrated that the patient was in mild DKA, with newly diagnosed diabetes.
    • Solution:  Recognize that patients have the potential to be sick regardless of initial triage level.  Triage cueing may also set up another cognitive bias, Diagnostic Momentum, where a patient's workup is based solely on one diagnosis or label (hand-offs at sign out serve as notorious examples).  
    Premature closure - when one accepts a diagnosis before verification of the diagnosis. 
    • Case: A 48 year old male is transferred from an outside hospital for CHF.  He presented with acute dyspnea accompanied by some pinkish phlegm.  He denies chest pain, pressure, leg swelling, travel, or cough. He was slightly hypertensive, sating 93% on 3L (non-smoker). Troponin was negative, ecg showed potentially new LBBB. Patient was given furosemide and a diagnosis of CHF. Upon arrival to our ED he had a BNP of 52 and was found to have a PE upon further work up since his story of CHF didn't seem to fit with our independent evaluation.
    • Solution:  Look at the evidence that both supports and refutes the diagnosis and, if lacking, obtain appropriate evidence.
    Confirmation bias - look for evidence to confirm the hypothesis rather than searching for evidence to refute.
    • Case:  A 40-something year old patient presents to the hospital with nausea, vomiting, and epigastric pain. The patient has a history of pancreatitis and helicobacter pylori in addition to the all-American trio:  diabetes, hypertension, and hypercholesterolemia.  When the lipase came back over 300 and the bilirubin and transaminases were also fairly elevated, the patient was observed until his pain and nausea were controlled and he passed a PO challenge.  The patient bounced back within 24 hours in heart failure from a sizable MI.
    • Solution:  Look at incoming data objectively before selecting out certain pieces.
    Search Satisfying - the tendency to cease looking for other findings/disease processes once something is found.
    • Case:  A patient presents s/p motorcycle crash with right arm pain.  Exam demonstrates an avulsion injury over the patient's right elbow.  X-rays were negative, the wound was repaired, and the patient was readied for discharge.  Upon an additional exam, the patient had tenderness in the anatomic snuff box and we found the following:
    Scaphoid Fracture!
    • Solution:  Ask yourself - Is there anything else going on here? ATLS has helped decrease the tendency for search satisfying bias in trauma situations through algorithms.
    Availability and Non-availability - the greater prevalence (in the ED,literature,community,news,etc), the more likely we will think of and pursue the diagnosis (and the converse also holds true).
    • Case:  A 4 year old male presents with several days of fever.  He also had cracking of his lips, a maculopapular rash, and cervical lymphadenopathy.  The patient was diagnosed with Kawasaki Disease after a day.  The next several patients that came in with more than a few days of fever got complete workups/evaluation for Kawasaki. 
    • Solution:  Ask yourself - Is the diagnosis based on the case and data or based on something you're comfortable with?  Uncommon things happen too - keep these in mind as well (I'm biased as I love a good Zebra!).
    Ascertainment Bias - one sees what one expects to see (self-fulfilling prophecy)
    • Case: A 34 year old male, well known to the ED and EMS for frequent overdoses, presents with AMS and respiratory depression after his friends watched him shoot up heroin.  The patient was brought in with the diagnosis of overdose and his initial workup and treatment revolved around that one diagnosis.  Eventually the patient required intubation and upon further exam was noted to have unequal pupils.  Although this "frequent flyer" did have some level of overdose going on, the label as a "frequent flyer" and "overdose" initially obscured the fact that he was actively herniating due to a large subdural hematoma.
    • Solution:  Realize that patients who abuse drugs or have "red flag" diagnoses or allergies get sick, too. Look at each patient with fresh eyes.
    As a student, I force myself to generate 5 items on a differential before I present.  Sometimes this is ridiculous and a clear stretch but I use that tiny bit of time to think about why I'm thinking the way I am and potentially identify some of my cognitive bias.  As information comes in from further evaluation, diagnostics, etc I look at the data and integrate it into my leading diagnosis, as well as my differential.  It really doesn't take additional time if I force myself to do it every time.

    We will never be able to eliminate all errors, especially since systems errors play an enormous role in medical errors (and contribute to cognitive error), but perhaps we can train ourselves to reduce those that are in our control.  Life in the Fast Lane provides some succinct case-based insight into cognitive errors with these case scenarios.  There's some argument that recognition of these biases may not translate into meaningful patient outcomes, but I still think it's good form to think with intention and act when necessary.  Also, if you haven't yet, check out Dr. Patrick Croskerry's  free lectures,  on the subject (most span all of clinical decision making and errors).

    References: 
    Croskerry, P. The importance of Cognitive Errors in Diagnosis and Strategies to Minimize Them.  Academic Medicine.  August 2003, Vol 78, Issue 8. p775-780.
    Croskerry, P.  Achieving Quality in Clinical Decision Making:  Cognitive Strategies and Detection of Bias.  Academic Emergency Medicine.  Nov 2002, Vol 9. No 11.
    Jepson, Zak.  University of Massachusetts.  Medical Student Lecture. August 15, 2012.
    08.30.12
    by

    Anchors Aweigh! Cognitive Bias – Where IS This Ship Headed?

    The Gist:  We all succumb to cognitive errors from time to time.  Identifying these errors in our medical decision making though exercising metacognition may improve patient safety but it may also allow us to be better clinicians.  NB:  This is not a comprehensive review of all types of cognitive biases, which one can find here in "List 1."  Rather, this is a synopsis of some of the commonest cognitive biases, which I've learned from first-hand.

    Anchoring Bias     - when a first impression or one piece of evidence exerts undue influence in the diagnostic process.
    • Case:  Listen to a great new blogger/podcaster, Dr. Bob Stuntz, present a case on Anchoring Bias in which he gives an excellent example of the patient who comes in complaining of "I have a kidney stone."
    • Solution: wait until information about the case is complete before forming an impression or selling yourself on a diagnosis.  Note:  clearly in some critical situations one must act before information is complete.   
    Triage Cueing - bias initiated by the patient's initial triage level, assuming that a patient can't be sicker than their triage level.  
    • Case:  A patient was placed in the "minor care" area for a "sore throat."  The patient's PMH included hypertension and the history elucidated that the patient's complaint was more of a dry throat (drinking copious amounts of water) coupled with a yeast infection that wouldn't go away.  She also generally felt terrible and weak.  The attending was initially wary of the idea of a fingerstick glucose level but acquiesced after discussing that polydipsia and intractable yeast infections are harbingers of uncontrolled diabetes.  The result = 587 mg/dL.  Chemistry demonstrated that the patient was in mild DKA, with newly diagnosed diabetes.
    • Solution:  Recognize that patients have the potential to be sick regardless of initial triage level.  Triage cueing may also set up another cognitive bias, Diagnostic Momentum, where a patient's workup is based solely on one diagnosis or label (hand-offs at sign out serve as notorious examples).  
    Premature closure - when one accepts a diagnosis before verification of the diagnosis. 
    • Case: A 48 year old male is transferred from an outside hospital for CHF.  He presented with acute dyspnea accompanied by some pinkish phlegm.  He denies chest pain, pressure, leg swelling, travel, or cough. He was slightly hypertensive, sating 93% on 3L (non-smoker). Troponin was negative, ecg showed potentially new LBBB. Patient was given furosemide and a diagnosis of CHF. Upon arrival to our ED he had a BNP of 52 and was found to have a PE upon further work up since his story of CHF didn't seem to fit with our independent evaluation.
    • Solution:  Look at the evidence that both supports and refutes the diagnosis and, if lacking, obtain appropriate evidence.
    Confirmation bias - look for evidence to confirm the hypothesis rather than searching for evidence to refute.
    • Case:  A 40-something year old patient presents to the hospital with nausea, vomiting, and epigastric pain. The patient has a history of pancreatitis and helicobacter pylori in addition to the all-American trio:  diabetes, hypertension, and hypercholesterolemia.  When the lipase came back over 300 and the bilirubin and transaminases were also fairly elevated, the patient was observed until his pain and nausea were controlled and he passed a PO challenge.  The patient bounced back within 24 hours in heart failure from a sizable MI.
    • Solution:  Look at incoming data objectively before selecting out certain pieces.
    Search Satisfying - the tendency to cease looking for other findings/disease processes once something is found.
    • Case:  A patient presents s/p motorcycle crash with right arm pain.  Exam demonstrates an avulsion injury over the patient's right elbow.  X-rays were negative, the wound was repaired, and the patient was readied for discharge.  Upon an additional exam, the patient had tenderness in the anatomic snuff box and we found the following:
    Scaphoid Fracture!
    • Solution:  Ask yourself - Is there anything else going on here? ATLS has helped decrease the tendency for search satisfying bias in trauma situations through algorithms.
    Availability and Non-availability - the greater prevalence (in the ED,literature,community,news,etc), the more likely we will think of and pursue the diagnosis (and the converse also holds true).
    • Case:  A 4 year old male presents with several days of fever.  He also had cracking of his lips, a maculopapular rash, and cervical lymphadenopathy.  The patient was diagnosed with Kawasaki Disease after a day.  The next several patients that came in with more than a few days of fever got complete workups/evaluation for Kawasaki. 
    • Solution:  Ask yourself - Is the diagnosis based on the case and data or based on something you're comfortable with?  Uncommon things happen too - keep these in mind as well (I'm biased as I love a good Zebra!).
    Ascertainment Bias - one sees what one expects to see (self-fulfilling prophecy)
    • Case: A 34 year old male, well known to the ED and EMS for frequent overdoses, presents with AMS and respiratory depression after his friends watched him shoot up heroin.  The patient was brought in with the diagnosis of overdose and his initial workup and treatment revolved around that one diagnosis.  Eventually the patient required intubation and upon further exam was noted to have unequal pupils.  Although this "frequent flyer" did have some level of overdose going on, the label as a "frequent flyer" and "overdose" initially obscured the fact that he was actively herniating due to a large subdural hematoma.
    • Solution:  Realize that patients who abuse drugs or have "red flag" diagnoses or allergies get sick, too. Look at each patient with fresh eyes.
    As a student, I force myself to generate 5 items on a differential before I present.  Sometimes this is ridiculous and a clear stretch but I use that tiny bit of time to think about why I'm thinking the way I am and potentially identify some of my cognitive bias.  As information comes in from further evaluation, diagnostics, etc I look at the data and integrate it into my leading diagnosis, as well as my differential.  It really doesn't take additional time if I force myself to do it every time.

    We will never be able to eliminate all errors, especially since systems errors play an enormous role in medical errors (and contribute to cognitive error), but perhaps we can train ourselves to reduce those that are in our control.  Life in the Fast Lane provides some succinct case-based insight into cognitive errors with these case scenarios.  There's some argument that recognition of these biases may not translate into meaningful patient outcomes, but I still think it's good form to think with intention and act when necessary.  Also, if you haven't yet, check out Dr. Patrick Croskerry's  free lectures,  on the subject (most span all of clinical decision making and errors).

    References: 
    Croskerry, P. The importance of Cognitive Errors in Diagnosis and Strategies to Minimize Them.  Academic Medicine.  August 2003, Vol 78, Issue 8. p775-780.
    Croskerry, P.  Achieving Quality in Clinical Decision Making:  Cognitive Strategies and Detection of Bias.  Academic Emergency Medicine.  Nov 2002, Vol 9. No 11.
    Jepson, Zak.  University of Massachusetts.  Medical Student Lecture. August 15, 2012.
    08.30.12
    by

    Anchors Aweigh! Cognitive Bias – Where IS This Ship Headed?

    The Gist:  We all succumb to cognitive errors from time to time.  Identifying these errors in our medical decision making though exercising metacognition may improve patient safety but it may also allow us to be better clinicians.  NB:  This is not a comprehensive review of all types of cognitive biases, which one can find here in "List 1."  Rather, this is a synopsis of some of the commonest cognitive biases, which I've learned from first-hand.

    Anchoring Bias     - when a first impression or one piece of evidence exerts undue influence in the diagnostic process.
    • Case:  Listen to a great new blogger/podcaster, Dr. Bob Stuntz, present a case on Anchoring Bias in which he gives an excellent example of the patient who comes in complaining of "I have a kidney stone."
    • Solution: wait until information about the case is complete before forming an impression or selling yourself on a diagnosis.  Note:  clearly in some critical situations one must act before information is complete.   
    Triage Cueing - bias initiated by the patient's initial triage level, assuming that a patient can't be sicker than their triage level.  
    • Case:  A patient was placed in the "minor care" area for a "sore throat."  The patient's PMH included hypertension and the history elucidated that the patient's complaint was more of a dry throat (drinking copious amounts of water) coupled with a yeast infection that wouldn't go away.  She also generally felt terrible and weak.  The attending was initially wary of the idea of a fingerstick glucose level but acquiesced after discussing that polydipsia and intractable yeast infections are harbingers of uncontrolled diabetes.  The result = 587 mg/dL.  Chemistry demonstrated that the patient was in mild DKA, with newly diagnosed diabetes.
    • Solution:  Recognize that patients have the potential to be sick regardless of initial triage level.  Triage cueing may also set up another cognitive bias, Diagnostic Momentum, where a patient's workup is based solely on one diagnosis or label.  
    Premature closure - when one accepts a diagnosis before verification of the diagnosis. 
    • Case: A 48 year old male is transferred from an outside hospital for CHF.  He presented with acute dyspnea accompanied by some pinkish phlegm.  He denies chest pain, pressure, leg swelling, travel, or cough.
    • Solution:  Look at the evidence that both supports and refutes the diagnosis and, if lacking, obtain appropriate evidence.
    Confirmation bias - look for evidence to confirm the hypothesis rather than searching for evidence to refute.
    • Case:  A 40-something year old patient presents to the hospital with nausea, vomiting, and epigastric pain. The patient has a history of pancreatitis and helicobacter pylori in addition to the all-American trio:  diabetes, hypertension, and hypercholesterolemia.  When the lipase came back over 300 and the bilirubin and transaminases were also fairly elevated, the patient was observed until his pain and nausea were controlled and he passed a PO challenge.  The patient bounced back within 24 hours in heart failure from a sizable MI.
    • Solution:  Look at incoming data objectively before selecting out certain pieces.
    Search Satisfying - the tendency to cease looking for other findings/disease processes once something is found.
    • Case:  A patient presents s/p motorcycle crash with right arm pain.  Exam demonstrates an avulsion injury over the patient's right elbow.  X-rays were negative, the wound was repaired, and the patient was readied for discharge.  Upon an additional exam, the patient had tenderness in the anatomic snuff box and we found the following:
    • Solution:  Ask yourself - Is there anything else going on here? ATLS has helped decrease the tendency for search satisfying bias in trauma situations through algorithms.
    Availability and Non-availability - the greater prevalence (in the ED,literature,community,news,etc), the more likely we will think of and pursue the diagnosis (and the converse also holds true).
    • Case:  A 4 year old male presents with several days of fever.  He also had cracking of his lips, a maculopapular rash, and cervical lymphadenopathy.  The patient was diagnosed with Kawasaki Disease after a day.  The next several patients that came in with more than a few days of fever got complete workups/evaluation for Kawasaki. 
    • Solution:  Ask yourself - Is the diagnosis based on the case and data or based on something you're comfortable with?  Uncommon things happen too - keep these in mind as well (I'm biased as I love a good Zebra!).
    As a student, I force myself to generate 5 items on a differential before I present.  Sometimes this is ridiculous and a clear stretch but I use that tiny bit of time to think about why I'm thinking the way I am and potentially identify some of my cognitive bias.  As information comes in from further evaluation, diagnostics, etc I look at the data and integrate it into my leading diagnosis, as well as my differential.  It really doesn't take additional time if I force myself to do it every time.

    We will never be able to eliminate all errors, but perhaps we can train ourselves to reduce those that are in our control.  Life in the Fast Lane provides some succinct case-based insight into cognitive errors with these case scenarios.  There's some argument that recognition of these biases may not translate into meaningful patient outcomes, but I still think it's good form to think with intention and act when necessary.  Also, if you haven't yet, check out Dr. Patrick Croskerry's  free lectures,  on the subject (most span all of clinical decision making and errors).

    Reference:
    Croskerry, P.  The Importance of Cognitive Errors in Diagnosis and Strategies to Minimize Them. Academic Medicine August 2003, Volume 78. Issue 8. p 775-780
    Croskerry, P.  Achieving Quality in Clinical Decision Making: Cognitive Strategies and Detection of Bias.  Academic Emergency Medicine. Nov 2002, Vol 9. No 11.
    Zak Jepson, MD.  University of Massachusetts Medical Student Lecture.  August 15, 2012.
    08.27.12
    by

    Thinking About Thinking

    The Gist:  Clinical reasoning in the EM setting is different than other arenas as one must often make life and death decisions (and actions) with limited information and even less time.  Our patients are often undifferentiated and nearly any ailment exists as a possibility.  Furthermore, EPs are constantly juggling multiple patients and responsibilities.  As a result, cognitive errors are common and play a role in clinical decision making (although this also applies to all fields of medicine).  Thinking about thinking or, "metacognition," may help reduce these cognitive errors to allow Emergency Physicians (EPs) to improve diagnostic and treatment decision making.   

    The case that made me care about cognitive errors:  A 40-something year old patient presented to the hospital with nausea, vomiting, and epigastric pain stating "this feels a lot like my pancreatitis."  The patient had a history of pancreatitis and helicobacter pylori in addition to the all-American trio:  diabetes, hypertension, and hypercholesterolemia.  The labs, work up, and patient all seemed to proclaim pancreatitis.  Unfortunately, the patient bounced back within a day in heart failure, status-post massive MI.  Ever since, I've been exceptionally wary of diabetics with nausea and vomiting and garnered a fascination with the thinking of an EP.

    In medical school, we're overtly taught clinical reasoning through data mining in the form of history, physical exam, and diagnostic testing.  I suppose we're subtly and indirectly taught to think about the way we integrate and assimilate this data into a coherent picture of the patient and an accurate diagnosis.  We subconsciously use heuristics, cognitive short cuts, to inform clinical gestalt.  My formal medical education, however, did not include any discussion of cognitive bias or meta-cognition until a resident at a program I rotated at gave a brief presentation on metacognition.
    • Apparently, we can reduce errors if we step back for a moment and think:  What doesn't fit? What have I failed to consider (perhaps a zebra? or a different horse?)?  What biases may be present?  What is leading me to think that this patient has X?
    This is so important that I wanted to disseminate this information to help others who strive to be excellent thinkers and swell clinicians.

    Basic systems of thinking.  Between which we have the capability to toggle, which we should probably exercise more often. Check out this lecture.
    • "System 1" or "Fast":  This is the instinct, intuitive, adaptive, associative, quick thinking.  We use this system when we say, "this patient just looks sick" or "I have this gut feeling the patient has ______."  Caution: medical students and trainees should really not rely on this type of thinking although it is often key in EM (think clinical gestalt)
    • "System 2" or "Analytic":  This is a slower process of thinking which is more deliberate and analytic.
    Common EM thinking patterns:
    • Hypothetico-Deductive Model:  One of the most common cognitive pathways used in medicine - useful in non-critical situations, as algorithms such as ATLS and ACLS tend to dominate in the more critical circumstances.  
      • Main steps:  Generation, Evaluation, Refinement, Verification.  Errors can be present in any step.  
      • Error in Generation - failure to consider a potential diagnosis (influenced by disease prevalence, atypical presentations, etc).  
      • Error in Evaluation - problems in gathering data, interpreting and assimilating the data, and putting the data in the proper context.
      • Error in Verification - failure to ensure that the final diagnosis fits with the clinical picture and established data/workup.
    • Pattern Recognition Model:  This dominates when an experienced clinician uses clinical gestalt to inform the diagnosis rather than generating a complete differential diagnosis (and thereby prone to error for failing to consider alternative diagnoses).
    • Rule Out Worse Case Scenario Model:  Some clinicians employ this most of the time and others tend to apply it when particularly high-risk diagnoses are on the table.  This method of reasoning is expensive and exposes the patient to excess harms through extensive investigations.
    Why may the ED be a breeding ground for cognitive error?
    • High levels of diagnostic uncertainty
    • High decision density and cognitive load
    • High levels of activity
    • Inexperience of some providers (and students)
    • Interruptions and distractions
    • Shift changes
    • Many of these, integrated, produce fatigue
    • These errors occur in every facet of medicine but in EM, there is a certain expectation that EPs not miss the badness (or anything).
    The papers to read (note:  Dr. Patrick Croskerry is a world-reknowned expert in this arena.  If you're looking for even more to read, check out his plethora of articles.  Also, he has several free talks on freeemergencytalks.net, which can be converted to podcasts within iTunes)  


    Life in the Fast Lane provides some succinct case-based insight into cognitive errors with To Err is Human 1 and To Err is Human 2


    Achieving quality in clinical decision making: cognitive strategies and detection of bias - Croskerry


    This article, also by Croskerry has a rather complete list of cognitive errors in the tables embedded in the free text article.



    Other References:
    Jepson, Zak. University of Massachusetts.  Medical Student Lecture. August 15, 2012.
    08.27.12
    by

    Thinking About Thinking

    The Gist:  Clinical reasoning in the EM setting is different than other arenas as one must often make decisions with limited information and even less time.  Our patients are often undifferentiated and nearly any ailment exists as a possibility.  Furthermore, EPs are constantly juggling multiple patients and responsibilities.  As a result, cognitive errors are common and play a role in clinical decision making (although this also applies to all fields of medicine).  Thinking about thinking or, "metacognition," may help reduce these cognitive errors to allow Emergency Physicians (EPs) to improve diagnostic and treatment decision making.   

    The case that made me care about cognitive errors:  A 40-something year old patient presents to the hospital with nausea, vomiting, and epigastric pain stating "this feels a lot like my pancreatitis."  The patient has a history of pancreatitis and helicobacter pylori in addition to the all-American trio:  diabetes, hypertension, and hypercholesterolemia.  The labs, work up, and patient all seemed to proclaim pancreatitis.  Unfortunately, the patient bounced back within a day in heart failure, status-post massive MI.  Ever since, I've been exceptionally wary of diabetics with nausea and vomiting and garnered a fascination with the thinking of an EP.

    In medical school, we're overtly taught clinical reasoning through data mining in the form of history, physical exam, and diagnostic testing.  I suppose we're subtly and indirectly taught to think about the way we integrate and assimilate this data into a coherent picture of the patient and an accurate diagnosis.  We subconsciously use heuristics, cognitive short cuts, to inform clinical gestalt.  My formal medical education, however, did not include any discussion of cognitive bias or meta-cognition until a resident at a program I rotated at gave a brief presentation on metacognition.
    • Apparently, we can reduce errors if we step back for a moment and think:  What doesn't fit? What have I failed to consider (perhaps a zebra? or a different horse?)?  What biases may be present?  What is leading me to think that this patient has X?
    This is so important that I wanted to disseminate this information to help others who strive to be excellent thinkers and swell clinicians.

    Basic systems of thinking.  Between which we have the capability to toggle, which we should probably exercise more often. Check out this lecture.
    • "System 1" or "Fast":  This is the instinct, intuitive, adaptive, associative, quick thinking.  We use this system when we say, "this patient just looks sick" or "I have this gut feeling the patient has ______."  Caution: medical students and trainees should really not rely on this type of thinking although it is often key in EM (think clinical gestalt)
    • "System 2" or "Analytic":  This is a slower process of thinking which is more deliberate and analytic.
    Common EM thinking patterns:
    • Hypothetico-Deductive Model:  One of the most common cognitive pathways used in medicine - useful in non-critical situations, as algorithms such as ATLS and ACLS tend to dominate in the more critical circumstances.  
      • Main steps:  Generation, Evaluation, Refinement, Verification.  Errors can be present in any step.  
      • Error in Generation - failure to consider a potential diagnosis (influenced by disease prevalence, atypical presentations, etc).  
      • Error in Evaluation - problems in gathering data, interpreting and assimilating the data, and putting the data in the proper context.
      • Error in Verification - failure to ensure that the final diagnosis fits with the clinical picture and established data/workup.
    • Pattern Recognition Model:  This dominates when an experienced clinician uses clinical gestalt to inform the diagnosis rather than generating a complete differential diagnosis (and thereby prone to error for failing to consider alternative diagnoses).
    • Rule Out Worse Case Scenario Model:  Some clinicians employ this most of the time and others tend to apply it when particularly high-risk diagnoses are on the table.  This method of reasoning is expensive and exposes the patient to excess harms through extensive investigations.
    The papers to read (note:  Dr. Patrick Croskerry is a world-reknowned expert in this arena.  If you're looking for even more to read, check out his plethora of articles.  Also, he has several free talks on freeemergencytalks.net, which can be converted to podcasts within iTunes)  


    Life in the Fast Lane provides some succinct case-based insight into cognitive errors with To Err is Human 1 and To Err is Human 2


    Achieving quality in clinical decision making: cognitive strategies and detection of bias - Croskerry


    This article, also by Croskerry has a rather complete list of cognitive errors in the tables embedded in the free text article.



    Next up:  Anchoring, Triage, and Confirmation...Examples of Cognitive Bias/Error and Solutions
    08.27.12
    by

    Thinking About Thinking

    The Gist:  Clinical reasoning in the EM setting is different than other arenas as one must often make decisions with limited information and even less time.  Our patients are often undifferentiated and nearly any ailment exists as a possibility.  Furthermore, EPs are constantly juggling multiple patients and responsibilities.  As a result, cognitive errors are common and play a role in clinical decision making (although this also applies to all fields of medicine).  Thinking about thinking or, "metacognition," may help reduce these cognitive errors to allow Emergency Physicians (EPs) to improve diagnostic and treatment decision making.   

    The case that made me care about cognitive errors:  A 40-something year old patient presents to the hospital with nausea, vomiting, and epigastric pain stating "this feels a lot like my pancreatitis."  The patient has a history of pancreatitis and helicobacter pylori in addition to the all-American trio:  diabetes, hypertension, and hypercholesterolemia.  The labs, work up, and patient all seemed to proclaim pancreatitis.  Unfortunately, the patient bounced back within a day in heart failure, status-post massive MI.  Ever since, I've been exceptionally wary of diabetics with nausea and vomiting and garnered a fascination with the thinking of an EP.

    In medical school, we're overtly taught clinical reasoning through data mining in the form of history, physical exam, and diagnostic testing.  I suppose we're subtly and indirectly taught to think about the way we integrate and assimilate this data into a coherent picture of the patient and an accurate diagnosis.  We subconsciously use heuristics, cognitive short cuts, to inform clinical gestalt.  My formal medical education, however, did not include any discussion of cognitive bias or meta-cognition until a resident at a program I rotated at gave a brief presentation on metacognition.
    • Apparently, we can reduce errors if we step back for a moment and think:  What doesn't fit? What have I failed to consider (perhaps a zebra? or a different horse?)?  What biases may be present?  What is leading me to think that this patient has X?
    This is so important that I wanted to disseminate this information to help others who strive to be excellent thinkers and swell clinicians.

    Basic systems of thinking.  Between which we have the capability to toggle, which we should probably exercise more often. Check out this lecture.
    • "System 1" or "Fast":  This is the instinct, intuitive, adaptive, associative, quick thinking.  We use this system when we say, "this patient just looks sick" or "I have this gut feeling the patient has ______."  Caution: medical students and trainees should really not rely on this type of thinking although it is often key in EM (think clinical gestalt)
    • "System 2" or "Analytic":  This is a slower process of thinking which is more deliberate and analytic.
    Common EM thinking patterns:
    • Hypothetico-Deductive Model:  One of the most common cognitive pathways used in medicine - useful in non-critical situations, as algorithms such as ATLS and ACLS tend to dominate in the more critical circumstances.  
      • Main steps:  Generation, Evaluation, Refinement, Verification.  Errors can be present in any step.  
      • Error in Generation - failure to consider a potential diagnosis (influenced by disease prevalence, atypical presentations, etc).  
      • Error in Evaluation - problems in gathering data, interpreting and assimilating the data, and putting the data in the proper context.
      • Error in Verification - failure to ensure that the final diagnosis fits with the clinical picture and established data/workup.
    • Pattern Recognition Model:  This dominates when an experienced clinician uses clinical gestalt to inform the diagnosis rather than generating a complete differential diagnosis (and thereby prone to error for failing to consider alternative diagnoses).
    • Rule Out Worse Case Scenario Model:  Some clinicians employ this most of the time and others tend to apply it when particularly high-risk diagnoses are on the table.  This method of reasoning is expensive and exposes the patient to excess harms through extensive investigations.
    The papers to read (note:  Dr. Patrick Croskerry is a world-reknowned expert in this arena.  If you're looking for even more to read, check out his plethora of articles.  Also, he has several free talks on freeemergencytalks.net, which can be converted to podcasts within iTunes)  


    Life in the Fast Lane provides some succinct case-based insight into cognitive errors with To Err is Human 1 and To Err is Human 2


    Achieving quality in clinical decision making: cognitive strategies and detection of bias - Croskerry


    This article, also by Croskerry has a rather complete list of cognitive errors in the tables embedded in the free text article.



    Next up:  Anchoring, Triage, and Confirmation...Examples of Cognitive Bias/Error and Solutions
    08.27.12
    by

    Thinking About Thinking

    The Gist:  Clinical reasoning in the EM setting is different than other arenas as one must often make life and death decisions (and actions) with limited information and even less time.  Our patients are often undifferentiated and nearly any ailment exists as a possibility.  Furthermore, EPs are constantly juggling multiple patients and responsibilities.  As a result, cognitive errors are common and play a role in clinical decision making (although this also applies to all fields of medicine).  Thinking about thinking or, "metacognition," may help reduce these cognitive errors to allow Emergency Physicians (EPs) to improve diagnostic and treatment decision making.   

    The case that made me care about cognitive errors:  A 40-something year old patient presented to the hospital with nausea, vomiting, and epigastric pain stating "this feels a lot like my pancreatitis."  The patient had a history of pancreatitis and helicobacter pylori in addition to the all-American trio:  diabetes, hypertension, and hypercholesterolemia.  The labs, work up, and patient all seemed to proclaim pancreatitis.  Unfortunately, the patient bounced back within a day in heart failure, status-post massive MI.  Ever since, I've been exceptionally wary of diabetics with nausea and vomiting and garnered a fascination with the thinking of an EP.

    In medical school, we're overtly taught clinical reasoning through data mining in the form of history, physical exam, and diagnostic testing.  I suppose we're subtly and indirectly taught to think about the way we integrate and assimilate this data into a coherent picture of the patient and an accurate diagnosis.  We subconsciously use heuristics, cognitive short cuts, to inform clinical gestalt.  My formal medical education, however, did not include any discussion of cognitive bias or meta-cognition until a resident at a program I rotated at gave a brief presentation on metacognition.
    • Apparently, we can reduce errors if we step back for a moment and think:  What doesn't fit? What have I failed to consider (perhaps a zebra? or a different horse?)?  What biases may be present?  What is leading me to think that this patient has X?
    This is so important that I wanted to disseminate this information to help others who strive to be excellent thinkers and swell clinicians.

    Basic systems of thinking.  Between which we have the capability to toggle, which we should probably exercise more often. Check out this lecture.
    • "System 1" or "Fast":  This is the instinct, intuitive, adaptive, associative, quick thinking.  We use this system when we say, "this patient just looks sick" or "I have this gut feeling the patient has ______."  Caution: medical students and trainees should really not rely on this type of thinking although it is often key in EM (think clinical gestalt)
    • "System 2" or "Analytic":  This is a slower process of thinking which is more deliberate and analytic.
    Common EM thinking patterns:
    • Hypothetico-Deductive Model:  One of the most common cognitive pathways used in medicine - useful in non-critical situations, as algorithms such as ATLS and ACLS tend to dominate in the more critical circumstances.  
      • Main steps:  Generation, Evaluation, Refinement, Verification.  Errors can be present in any step.  
      • Error in Generation - failure to consider a potential diagnosis (influenced by disease prevalence, atypical presentations, etc).  
      • Error in Evaluation - problems in gathering data, interpreting and assimilating the data, and putting the data in the proper context.
      • Error in Verification - failure to ensure that the final diagnosis fits with the clinical picture and established data/workup.
    • Pattern Recognition Model:  This dominates when an experienced clinician uses clinical gestalt to inform the diagnosis rather than generating a complete differential diagnosis (and thereby prone to error for failing to consider alternative diagnoses).
    • Rule Out Worse Case Scenario Model:  Some clinicians employ this most of the time and others tend to apply it when particularly high-risk diagnoses are on the table.  This method of reasoning is expensive and exposes the patient to excess harms through extensive investigations.
    Why may the ED be a breeding ground for cognitive error?
    • High levels of diagnostic uncertainty
    • High decision density and cognitive load
    • High levels of activity
    • Inexperience of some providers (and students)
    • Interruptions and distractions
    • Shift changes
    • Many of these, integrated, produce fatigue
    • These errors occur in every facet of medicine but in EM, there is a certain expectation that EPs not miss the badness (or anything).
    The papers to read (note:  Dr. Patrick Croskerry is a world-reknowned expert in this arena.  If you're looking for even more to read, check out his plethora of articles.  Also, he has several free talks on freeemergencytalks.net, which can be converted to podcasts within iTunes)  


    Life in the Fast Lane provides some succinct case-based insight into cognitive errors with To Err is Human 1 and To Err is Human 2


    Achieving quality in clinical decision making: cognitive strategies and detection of bias - Croskerry


    This article, also by Croskerry has a rather complete list of cognitive errors in the tables embedded in the free text article.



    Other References:
    Jepson, Zak. University of Massachusetts.  Medical Student Lecture. August 15, 2012.
    07.31.12
    by

    Trying Hard – Trials in EM Research

    The Gist:  If one follows EM blogs, podcasts, or tweets for any period of time, it's immediately apparent that application of evidenced based medicine is the expectation.  Within the EM context, however, research and evidence face incredible challenges, partially due to the improvisational, desperate nature of the job.  Global discourse over TXA in trauma and epinephrine in cardiac arrest highlight learning points regarding the complexity EM research.  Note: This was part of a behemoth post, so this is Part 2 (Part 1 takes a gander at the CRASH-2 trial and under-utilization of TXA in the context of study design/result interpretation).


    The papers behind many of these musings:  Effect of adrenaline on survival in out-of-hospital cardiac arrest: A randomised double-blind placebo-controlled trial. and Prehospital Epinephrine Use and Survival Among Patients With Out-of-Hospital Cardiac Arrest.  
    • On the PHARM Podcast, Episode 12, when Dr. Minh Le Cong and Tim Noonan highlighted some problems with trials in EM with medications like epi and they do a great job reviewing some of the issues below.  
    What makes evidence based medicine different in EM?

    Diversity of the Population - ED patients often have trauma or an undifferentiated illness/complaint that causes them to present to the ED.  Trauma, naturally, is not uniform and certainly not predictable in terms of enrolling patients. 
    • Mechanism of action -  There are seemingly infinite ways in which people manage to harm themselves or others.  Every study that investigates trauma will have some degree of variation (heterogeneity) in penetrating and blunt trauma, burns, etc.  Thus, inclusion criteria may rely on a clinician's judgment or an objective systemic endpoint (BP, HR, etc).
    • Predictability - Within a population, estimates exist regarding the incidence/prevalance of the disease.  One of the beauties of EM is never knowing what type of patient is going to roll through the doors next.  Sometimes we can guess (or hope), but that's about the extent.
    Cost - In EM, many therapies are relatively inexpensive:  chilled saline, epinephrine (epi) , and TXA are all fairly cheap.
    • Pharmaceutical companies are not inclined to sink significant funds into examining the efficacy of these therapies.  In stark contrast, some therapies like activated protein C (Xigris, drotrecogin alfa) seems to get a great deal of journal/media attention for an intervention with limited clinical utility and no proven benefit.  Activated protein C,  far more expensive than drugs such as TXA/epi, has a clear pharmaceutical backing drawing more research and publicity.
    Vulnerability of the Population  - The day a patient requires emergency care is often the worse day of their life.  
    • Oftentimes, one is unable to obtained informed consent for study participation due to the nature of a patient's injuries, mental status, or the critical nature of events.   The final rule on Exception From Informed Consent (EFIC) in the U.S. waived the need for informed consent in EM research in 1996. Note:  The Nov 2005 volume of Acad Emergency Medicine details this topic thoroughly.  Although in emergent situations, informed consent may be waived legally, IRBs often have issue with approving these studies.  This rule does not apply internationally.  For example, the authors of CRASH-2 reported that some of the delay in TXA/placebo administration existed in the delay in obtaining informed consent.  
    • The population is comprised of pregnant women and children, two groups that experimenters are already reticent to include in trials. 
    Unique Environment - A certain MacGyver-esque quality exists in EM where there's some agreement that nearly anything (reasonable) may be done in order to save a life.  Due to the oft undifferentiated and improvisational nature of the trade, it's much more difficult to go through many of the standard research protocols.   
    • Time proves critical in many EM situations.  Thus, a physician's impression of a situation (or gestalt) may be the only thing guiding critical care, as some diagnostic queries may take too long.  This is especially notable in the time frame that TXA works best (within 3 hours of trauma, but <1 hour is superior).  
    • Along these lines, a fraction of EM practice incorporates salvage therapy.  Individuals may have a lower threshold for utilizing a treatment due to the notion that the intervention is a "last-ditch effort."  The use of epinephrine in cardiac arrest is an example in which many people have questioned, "what can be the harm if the patient is already dead?"  Unfortunately, epinephrine's primary benefit seems to be in establishing ROSC so the patient's family (and the patient's body) then bears the burden of an alive patient with little to no neurological recovery.  Certainly some patient's fall into the area where they can have both ROSC and retained neurological function (therapeutic hypothermia!); however, the studies don't look promising that this is positive at the population level.  It's extremely difficult to refrain from doing something.  
    • The population is (generally) very sick.  Many cohorts have confounders or confusing secondary endpoints where survivor bias plays a significant role.  TXA's failure to significantly reduce blood transfusions in CRASH-2 may serve as an example of this.
    • Much of EM is protocol driven, particularly in the pre-hospital realm.  Thus, study design may need implementation/approval at the system level.  The initial study in Houston, TX regarding permissive hypotension in the penetrating trauma patient is an example of a successful study with a protocol based intervention. 
    Standard of Care - The current dialogue regarding epi in cardiac arrest serves as an excellent example of how a standard of care, widely accepted prior to rigorous studies and modern research design, requires one to assume the burden of disproof.
    • Placebo controlled trials may be difficult to get past an IRB with something that has become a "standard of care," even if the "standard of care" has never been adequately investigated.  
    This paper, by Dr. Tim Coats in the the BMJ, discusses the challenges of conventional research in the EM realm and advocates for emphasis on pragmatic trials over explanatory trials in EM.  It really is helpful.
    07.31.12
    by

    Trying Hard – Trials in EM Research

    The Gist:  If one follows EM blogs, podcasts, or tweets for any period of time, it's immediately apparent that application of evidenced based medicine is the expectation.  Within the EM context, however, research and evidence face incredible challenges, partially due to the improvisational, desperate nature of the job.  Global discourse over TXA in trauma and epinephrine in cardiac arrest highlight learning points regarding the complexity EM research.  Note: This was part of a behemoth post, so this is Part 2 (Part 1 takes a gander at the CRASH-2 trial and under-utilization of TXA in the context of study design/result interpretation).


    The papers behind many of these musings:  Effect of adrenaline on survival in out-of-hospital cardiac arrest: A randomised double-blind placebo-controlled trial. and Prehospital Epinephrine Use and Survival Among Patients With Out-of-Hospital Cardiac Arrest.  
    • On the PHARM Podcast, Episode 12, when Dr. Minh Le Cong and Tim Noonan highlighted some problems with trials in EM with medications like epi and they do a great job reviewing some of the issues below.  
    What makes evidence based medicine different in EM?

    Diversity of the Population - ED patients often have trauma or an undifferentiated illness/complaint that causes them to present to the ED.  Trauma, naturally, is not uniform and certainly not predictable in terms of enrolling patients. 
    • Mechanism of action -  There are seemingly infinite ways in which people manage to harm themselves or others.  Every study that investigates trauma will have some degree of variation (heterogeneity) in penetrating and blunt trauma, burns, etc.  Thus, inclusion criteria may rely on a clinician's judgment or an objective systemic endpoint (BP, HR, etc).
    • Predictability - Within a population, estimates exist regarding the incidence/prevalance of the disease.  One of the beauties of EM is never knowing what type of patient is going to roll through the doors next.  Sometimes we can guess (or hope), but that's about the extent.
    Cost - In EM, many therapies are relatively inexpensive:  chilled saline, epinephrine (epi) , and TXA are all fairly cheap.
    • Pharmaceutical companies are not inclined to sink significant funds into examining the efficacy of these therapies.  In stark contrast, some therapies like activated protein C (Xigris, drotrecogin alfa) seems to get a great deal of journal/media attention for an intervention with limited clinical utility and no proven benefit.  Activated protein C,  far more expensive than drugs such as TXA/epi, has a clear pharmaceutical backing drawing more research and publicity.
    Vulnerability of the Population  - The day a patient requires emergency care is often the worse day of their life.  
    • Oftentimes, one is unable to obtained informed consent for study participation due to the nature of a patient's injuries, mental status, or the critical nature of events.   The final rule on Exception From Informed Consent (EFIC) in the U.S. waived the need for informed consent in EM research in 1996. Note:  The Nov 2005 volume of Acad Emergency Medicine details this topic thoroughly.  Although in emergent situations, informed consent may be waived legally, IRBs often have issue with approving these studies.  This rule does not apply internationally.  For example, the authors of CRASH-2 reported that some of the delay in TXA/placebo administration existed in the delay in obtaining informed consent.  
    • The population is comprised of pregnant women and children, two groups that experimenters are already reticent to include in trials. 
    Unique Environment - A certain MacGyver-esque quality exists in EM where there's some agreement that nearly anything (reasonable) may be done in order to save a life.  Due to the oft undifferentiated and improvisational nature of the trade, it's much more difficult to go through many of the standard research protocols.   
    • Time proves critical in many EM situations.  Thus, a physician's impression of a situation (or gestalt) may be the only thing guiding critical care, as some diagnostic queries may take too long.  This is especially notable in the time frame that TXA works best (within 3 hours of trauma, but <1 hour is superior).  
    • Along these lines, a fraction of EM practice incorporates salvage therapy.  Individuals may have a lower threshold for utilizing a treatment due to the notion that the intervention is a "last-ditch effort."  The use of epinephrine in cardiac arrest is an example in which many people have questioned, "what can be the harm if the patient is already dead?"  Unfortunately, epinephrine's primary benefit seems to be in establishing ROSC so the patient's family (and the patient's body) then bears the burden of an alive patient with little to no neurological recovery.  Certainly some patient's fall into the area where they can have both ROSC and retained neurological function (therapeutic hypothermia!); however, the studies don't look promising that this is positive at the population level.  It's extremely difficult to refrain from doing something.  
    • The population is (generally) very sick.  Many cohorts have confounders or confusing secondary endpoints where survivor bias plays a significant role.  TXA's failure to significantly reduce blood transfusions in CRASH-2 may serve as an example of this.
    • Much of EM is protocol driven, particularly in the pre-hospital realm.  Thus, study design may need implementation/approval at the system level.  The initial study in Houston, TX regarding permissive hypotension in the penetrating trauma patient is an example of a successful study with a protocol based intervention. 
    Standard of Care - The current dialogue regarding epi in cardiac arrest serves as an excellent example of how a standard of care, widely accepted prior to rigorous studies and modern research design, requires one to assume the burden of disproof.
    • Placebo controlled trials may be difficult to get past an IRB with something that has become a "standard of care," even if the "standard of care" has never been adequately investigated.  
    This paper, by Dr. Tim Coats in the the BMJ, discusses the challenges of conventional research in the EM realm and advocates for emphasis on pragmatic trials over explanatory trials in EM.  It really is helpful.
    07.31.12
    by

    Trying Hard – Trials in EM Research

    The Gist:  If one follows EM blogs, podcasts, or tweets for any period of time, it's immediately apparent that application of evidenced based medicine is the expectation.  Within the EM context, however, research and evidence face incredible challenges, partially due to the improvisational, desperate nature of the job.  Global discourse over TXA in trauma and epinephrine in cardiac arrest highlight learning points regarding the complexity EM research.  Note: This was part of a behemoth post, so this is Part 2 (Part 1 takes a gander at the CRASH-2 trial and under-utilization of TXA in the context of study design/result interpretation).


    The papers behind many of these musings:  Effect of adrenaline on survival in out-of-hospital cardiac arrest: A randomised double-blind placebo-controlled trial. and Prehospital Epinephrine Use and Survival Among Patients With Out-of-Hospital Cardiac Arrest.  
    • On the PHARM Podcast, Episode 12, when Dr. Minh Le Cong and Tim Noonan highlighted some problems with trials in EM with medications like epi and they do a great job reviewing some of the issues below.  
    What makes evidence based medicine different in EM?

    Diversity of the Population - ED patients often have trauma or an undifferentiated illness/complaint that causes them to present to the ED.  Trauma, naturally, is not uniform and certainly not predictable in terms of enrolling patients. 
    • Mechanism of action -  There are seemingly infinite ways in which people manage to harm themselves or others.  Every study that investigates trauma will have some degree of variation (heterogeneity) in penetrating and blunt trauma, burns, etc.  Thus, inclusion criteria may rely on a clinician's judgment or an objective systemic endpoint (BP, HR, etc).
    • Predictability - Within a population, estimates exist regarding the incidence/prevalance of the disease.  One of the beauties of EM is never knowing what type of patient is going to roll through the doors next.  Sometimes we can guess (or hope), but that's about the extent.
    Cost - In EM, many therapies are relatively inexpensive:  chilled saline, epinephrine (epi) , and TXA are all fairly cheap.
    • Pharmaceutical companies are not inclined to sink significant funds into examining the efficacy of these therapies.  In stark contrast, some therapies like activated protein C (Xigris, drotrecogin alfa) seems to get a great deal of journal/media attention for an intervention with limited clinical utility and no proven benefit.  Activated protein C,  far more expensive than drugs such as TXA/epi, has a clear pharmaceutical backing drawing more research and publicity.
    Vulnerability of the Population  - The day a patient requires emergency care is often the worse day of their life.  
    • Oftentimes, one is unable to obtained informed consent for study participation due to the nature of a patient's injuries, mental status, or the critical nature of events.   The final rule on Exception From Informed Consent (EFIC) in the U.S. waived the need for informed consent in EM research in 1996. Note:  The Nov 2005 volume of Acad Emergency Medicine details this topic thoroughly.  Although in emergent situations, informed consent may be waived legally, IRBs often have issue with approving these studies.  This rule does not apply internationally.  For example, the authors of CRASH-2 reported that some of the delay in TXA/placebo administration existed in the delay in obtaining informed consent.  
    • The population is comprised of pregnant women and children, two groups that experimenters are already reticent to include in trials. 
    Unique Environment - A certain MacGyver-esque quality exists in EM where there's some agreement that nearly anything (reasonable) may be done in order to save a life.  Due to the oft undifferentiated and improvisational nature of the trade, it's much more difficult to go through many of the standard research protocols.   
    • Time proves critical in many EM situations.  Thus, a physician's impression of a situation (or gestalt) may be the only thing guiding critical care, as some diagnostic queries may take too long.  This is especially notable in the time frame that TXA works best (within 3 hours of trauma, but <1 hour is superior).  
    • Along these lines, a fraction of EM practice incorporates salvage therapy.  Individuals may have a lower threshold for utilizing a treatment due to the notion that the intervention is a "last-ditch effort."  The use of epinephrine in cardiac arrest is an example in which many people have questioned, "what can be the harm if the patient is already dead?"  Unfortunately, epinephrine's primary benefit seems to be in establishing ROSC so the patient's family (and the patient's body) then bears the burden of an alive patient with little to no neurological recovery.  Certainly some patient's fall into the area where they can have both ROSC and retained neurological function (therapeutic hypothermia!); however, the studies don't look promising that this is positive at the population level.  It's extremely difficult to refrain from doing something.  
    • The population is (generally) very sick.  Many cohorts have confounders or confusing secondary endpoints where survivor bias plays a significant role.  TXA's failure to significantly reduce blood transfusions in CRASH-2 may serve as an example of this.
    • Much of EM is protocol driven, particularly in the pre-hospital realm.  Thus, study design may need implementation/approval at the system level.  The initial study in Houston, TX regarding permissive hypotension in the penetrating trauma patient is an example of a successful study with a protocol based intervention. 
    Standard of Care - The current dialogue regarding epi in cardiac arrest serves as an excellent example of how a standard of care, widely accepted prior to rigorous studies and modern research design, requires one to assume the burden of disproof.
    • Placebo controlled trials may be difficult to get past an IRB with something that has become a "standard of care," even if the "standard of care" has never been adequately investigated.  
    This paper, by Dr. Tim Coats in the the BMJ, discusses the challenges of conventional research in the EM realm and advocates for emphasis on pragmatic trials over explanatory trials in EM.  It really is helpful.
    07.30.12
    by

    Size Matters? – Tranexamic Acid in Trauma

    The Gist: There's a good bit of chatter in the EM world focused on picking apart literature and trials to ensure that decisions and clinical treatment are up to date and evidence based.  This is amazing and something many neglect as they merely peruse a paper's abstract.  Might there be a time, however, when one should let some study design technicalities slide?  I'm certainly not an expert on this subject, but a few recent debates on tranexamic acid (TXA) and epinephrine (epi) piqued my interest in this subject. Note: This was a behemoth post, so I've split it in two because my attention span is not nearly that long.

    Recently, I heard an impromptu debate from a grand rounds lecture on the CRASH 2 study regarding TXA in trauma patients.  The trial wasn't well received by the audience because of design issues.  I recalled attempting to sell my surgery attending on the idea after I listened to the EMCrit podcast on TXA...he was totally unaware of the drug.  This served as a impetus to review research/evidence problems specific to EM - an issue on my mind since the Japanese epi studies were published earlier this year, generating controversy regarding ROSC and neurological outcomes.    


    What did this RCT show?  Dr. Andy Neill of Emergency Medicine Ireland reviews and interprets the study here and the NNT review of TXA is also excellent. Basic rundown:
    • Reduction in all cause mortality (RR 0.91, CI  0.85-0.97, p=0.0035) when tranexamic acid was given to trauma patients who were bleeding or at risk for bleeding (2)
    • Reduction in the risk of bleeding death (RR 0.85, CI 0.76-0.96, p=0.0077) best benefit in patients who received it within 1 hour of injury (RR 0.68, p<0.0001) (2)
    • Subgroup analysis planned a-priori
    Ok, now onto some criticisms of the CRASH2 study:

    • Size - Some argue that the large scale of the study (n=20211 patients in 40 countries at 274 hospitals) weakened the study results.  Size seems to be one of the commonest reasons that a study is cited as weak.  In EM, some studies have small numbers because of the infrequency of some presentations (toxic ingestion, difficult airways, etc).  These studies are criticized for their lack of generalizability in other populations.  CRASH-2, however, received some criticism because the argument that the size created heterogeneity in the population.  Instead of believing that this might increase the generalizability across the globe, some believe that the size creates protocol standardization failure, meaning the results aren't actually applicable.  Also, it is true that large studies can achieve power more easily than smaller studies, perhaps leading to detection of small clinical benefits. 
    • Effect - Absolute reduction in bleeding death observed in the treatment group is only 0.8%, so the number needed to treat (NNT) is 125 versus a NNT of 67 in those who received TXA earlier in their course.  Thus, although statistically significant, the potential clinical benefit for an individual patient is small.  Furthermore, some of the endpoints such as transfusions, were not decreased by TXA.  
    • Protocol - Patients were entered into the study based on physician's determination that they are "reasonably certain anti-fibrinolytic agents are indicated."  This creates a subjective entry point rather than a quantitative, objective point.  
    • Time - The evidence strongly demonstrates that effect size depends on the time of administration.  Harm may exist in administration of TXA after 3 hours.  Due to transport time, some doubt their ability to meet this time frame. 

    So, then, why become a fan of TXA in the bleeding trauma patient?
    • TXA is extremely cheap for an intervention that may save lives.  The U.S. Department of Defense formulary cost is $39.12 per 10 mL vial containing 1 g of TXA ($80 for the regimen used in the trial). The cost at CVS Pharmacy is $101.99 per 10 mL vial containing 1 g of TXA ($204 for the regimen used in the trial) (1).  The drug also demonstrated cost-effectiveness in country-based analysis of the CRASH-2. 
    • With regard to the size of the trial, this study would suggest that the the benefits of TXA have the potential to be generalized worldwide (as the cohort was rather international), a quality that many studies lack.
    • In addition to the subjective entry point of a patient being at risk for significant hemorrhage, there was some objective criteria to guide clinicians. Ex: the patient had to have significant hemorrhage (systolic blood pressure less than 90 mmHg and/or heart rate more than 110 beats per minute), or meet the clinician's gestalt of being at risk of significant hemorrhage within 8 hours of the inciting event.
    • The side effect profile was remarkably good, especially in the group that TXA is really indicated for (early post-event, within 3 hours).  Compared with pharmaceuticals like Factor VII, which is markedly expensive, there is a paucity of thrombotic events associated with TXA.  Also, blood product transfusions are not benign.  Early utilization of this drug is likely far less expensive and harmful than massive tranfusions that often ensue.
    • The patients that are likely to qualify for TXA are incredibly ill.  The reduction in  mortality by absolute numbers may be modest, but this cohort doesn't generally do well regardless.  In an era when many other standard interventions have questionable efficacy (epinephrine in cardiac arrest, PPIs in UGIB, etc) rejection of the benefits of TXA seems in-congruent.
    • The time frame issue seems work-able, especially if TXA were implemented in the pre-hospital setting.  
    • The findings of CRASH2 have been demonstrated outside of this large trial.  The MATTERs study, a retrospective analysis of 293 patients who received TXA in the US and UK military combat setting in Afghanistan demonstrated a statistically significant mortality benefit in patients who received TXA compared with those who did not (17.4% vs 23.9%).  The patients that received TXA were sicker than those who didn't (mean Injury Severity Score, 25.2 vs 22.5, P .001) (4). 



    References:
    07.30.12
    by

    Size Matters? – Tranexamic Acid in Trauma

    The Gist: There's a good bit of chatter in the EM world focused on picking apart literature and trials to ensure that decisions and clinical treatment are up to date and evidence based.  This is amazing and something many neglect as they merely peruse a paper's abstract.  Might there be a time, however, when one should let some study design technicalities slide?  I'm certainly not an expert on this subject, but a few recent debates on tranexamic acid (TXA) and epinephrine (epi) piqued my interest in this subject. Note: This was a behemoth post, so I've split it in two because my attention span is not nearly that long.

    Recently, I heard an impromptu debate from a grand rounds lecture on the CRASH 2 study regarding TXA in trauma patients.  The trial wasn't well received by the audience because of design issues.  I recalled attempting to sell my surgery attending on the idea after I listened to the EMCrit podcast on TXA...he was totally unaware of the drug.  This served as a impetus to review research/evidence problems specific to EM - an issue on my mind since the Japanese epi studies were published earlier this year, generating controversy regarding ROSC and neurological outcomes.    


    What did this RCT show?  Dr. Andy Neill of Emergency Medicine Ireland reviews and interprets the study here and the NNT review of TXA is also excellent. Basic rundown:
    • Reduction in all cause mortality (RR 0.91, CI  0.85-0.97, p=0.0035) when tranexamic acid was given to trauma patients who were bleeding or at risk for bleeding (2)
    • Reduction in the risk of bleeding death (RR 0.85, CI 0.76-0.96, p=0.0077) best benefit in patients who received it within 1 hour of injury (RR 0.68, p<0.0001) (2)
    • Subgroup analysis planned a-priori
    Ok, now onto some criticisms of the CRASH2 study:

    • Size - Some argue that the large scale of the study (n=20211 patients in 40 countries at 274 hospitals) weakened the study results.  Size seems to be one of the commonest reasons that a study is cited as weak.  In EM, some studies have small numbers because of the infrequency of some presentations (toxic ingestion, difficult airways, etc).  These studies are criticized for their lack of generalizability in other populations.  CRASH-2, however, received some criticism because the argument that the size created heterogeneity in the population.  Instead of believing that this might increase the generalizability across the globe, some believe that the size creates protocol standardization failure, meaning the results aren't actually applicable.  Also, it is true that large studies can achieve power more easily than smaller studies, perhaps leading to detection of small clinical benefits. 
    • Effect - Absolute reduction in bleeding death observed in the treatment group is only 0.8%, so the number needed to treat (NNT) is 125 versus a NNT of 67 in those who received TXA earlier in their course.  Thus, although statistically significant, the potential clinical benefit for an individual patient is small.  Furthermore, some of the endpoints such as transfusions, were not decreased by TXA.  
    • Protocol - Patients were entered into the study based on physician's determination that they are "reasonably certain anti-fibrinolytic agents are indicated."  This creates a subjective entry point rather than a quantitative, objective point.  
    • Time - The evidence strongly demonstrates that effect size depends on the time of administration.  Harm may exist in administration of TXA after 3 hours.  Due to transport time, some doubt their ability to meet this time frame. 

    So, then, why become a fan of TXA in the bleeding trauma patient?
    • TXA is extremely cheap for an intervention that may save lives.  The U.S. Department of Defense formulary cost is $39.12 per 10 mL vial containing 1 g of TXA ($80 for the regimen used in the trial). The cost at CVS Pharmacy is $101.99 per 10 mL vial containing 1 g of TXA ($204 for the regimen used in the trial) (1).  The drug also demonstrated cost-effectiveness in country-based analysis of the CRASH-2. 
    • With regard to the size of the trial, this study would suggest that the the benefits of TXA have the potential to be generalized worldwide (as the cohort was rather international), a quality that many studies lack.
    • In addition to the subjective entry point of a patient being at risk for significant hemorrhage, there was some objective criteria to guide clinicians. Ex: the patient had to have significant hemorrhage (systolic blood pressure less than 90 mmHg and/or heart rate more than 110 beats per minute), or meet the clinician's gestalt of being at risk of significant hemorrhage within 8 hours of the inciting event.
    • The side effect profile was remarkably good, especially in the group that TXA is really indicated for (early post-event, within 3 hours).  Compared with pharmaceuticals like Factor VII, which is markedly expensive, there is a paucity of thrombotic events associated with TXA.  Also, blood product transfusions are not benign.  Early utilization of this drug is likely far less expensive and harmful than massive tranfusions that often ensue.
    • The patients that are likely to qualify for TXA are incredibly ill.  The reduction in  mortality by absolute numbers may be modest, but this cohort doesn't generally do well regardless.  In an era when many other standard interventions have questionable efficacy (epinephrine in cardiac arrest, PPIs in UGIB, etc) rejection of the benefits of TXA seems in-congruent.
    • The time frame issue seems work-able, especially if TXA were implemented in the pre-hospital setting.  
    • The findings of CRASH2 have been demonstrated outside of this large trial.  The MATTERs study, a retrospective analysis of 293 patients who received TXA in the US and UK military combat setting in Afghanistan demonstrated a statistically significant mortality benefit in patients who received TXA compared with those who did not (17.4% vs 23.9%).  The patients that received TXA were sicker than those who didn't (mean Injury Severity Score, 25.2 vs 22.5, P .001) (4). 



    References:
    07.30.12
    by

    Size Matters? – Tranexamic Acid in Trauma

    The Gist: There's a good bit of chatter in the EM world focused on picking apart literature and trials to ensure that decisions and clinical treatment are up to date and evidence based.  This is amazing and something many neglect as they merely peruse a paper's abstract.  Might there be a time, however, when one should let some study design technicalities slide?  I'm certainly not an expert on this subject, but a few recent debates on tranexamic acid (TXA) and epinephrine (epi) piqued my interest in this subject. Note: This was a behemoth post, so I've split it in two because my attention span is not nearly that long.

    Recently, I heard an impromptu debate from a grand rounds lecture on the CRASH 2 study regarding TXA in trauma patients.  The trial wasn't well received by the audience because of design issues.  I recalled attempting to sell my surgery attending on the idea after I listened to the EMCrit podcast on TXA...he was totally unaware of the drug.  This served as a impetus to review research/evidence problems specific to EM - an issue on my mind since the epi studies were published.    


    What did this RCT show?  Dr. Andy Neill of Emergency Medicine Ireland reviews and interprets the study here and the NNT review of TXA is also excellent. Basic rundown:
    • Reduction in all cause mortality (RR 0.91, CI  0.85-0.97, p=0.0035) when tranexamic acid was given to trauma patients who were bleeding or at risk for bleeding (2)
    • Reduction in the risk of bleeding death (RR 0.85, CI 0.76-0.96, p=0.0077) best benefit in patients who received it within 1 hour of injury (RR 0.68, p<0.0001) (2)
    • Subgroup analysis planned a-priori

    Ok, now onto some criticisms of the CRASH2 study:

    • Size - Some argue that the large scale of the study (n=20211 patients in 40 countries at 274 hospitals) weakened the study results.  Size seems to be one of the commonest reasons that a study is cited as weak.  In EM, some studies have small numbers because of the infrequency of some presentations (toxic ingestion, difficult airways, etc).  These studies are criticized for their lack of generalizability in other populations.  CRASH-2, however, received some criticism because the argument that the size created heterogeneity in the population.  Instead of believing that this might increase the generalizability across the globe, some believe that the size creates protocol standardization failure, meaning the results aren't actually applicable.  Also, it is true that large studies can achieve power more easily than smaller studies, perhaps leading to detection of small clinical benefits. 
    • Effect - Absolute reduction in bleeding death observed in the treatment group is only 0.8%, so the number needed to treat (NNT) is 125 versus a NNT of 67 in those who received TXA earlier in their course.  Thus, although statistically significant, the potential clinical benefit for an individual patient is small.  Furthermore, some of the endpoints such as transfusions, were not decreased by TXA.  
    • Protocol - Patients were entered into the study based on physician's determination that they are "reasonably certain anti-fibrinolytic agents are indicated."  This creates a subjective entry point rather than a quantitative, objective point.  
    • Time - The evidence strongly demonstrates that effect size depends on the time of administration.  Harm may exist in administration of TXA after 3 hours.  Due to transport time, some doubt their ability to meet this time frame. 
    So, then, why become a fan of TXA in the bleeding trauma patient?
    • TXA is extremely cheap for an intervention that may save lives.  The U.S. Department of Defense formulary cost is $39.12 per 10 mL vial containing 1 g of TXA ($80 for the regimen used in the trial). The cost at CVS Pharmacy is $101.99 per 10 mL vial containing 1 g of TXA ($204 for the regimen used in the trial) (1).  The drug also demonstrated cost-effectiveness in country-based analysis of the CRASH-2. 
    • With regard to the size of the trial, this study would suggest that the the benefits of TXA have the potential to be generalized worldwide (as the cohort was rather international), a quality that many studies lack.
    • In addition to the subjective entry point of a patient being at risk for significant hemorrhage, there was some objective criteria to guide clinicians. Ex: the patient had to have significant hemorrhage (systolic blood pressure less than 90 mmHg and/or heart rate more than 110 beats per minute), or meet the clinician's gestalt of being at risk of significant hemorrhage within 8 hours of the inciting event.
    • The side effect profile was remarkably good, especially in the group that TXA is really indicated for (early post-event, within 3 hours).  Compared with pharmaceuticals like Factor VII, which is markedly expensive, there is a paucity of thrombotic events associated with TXA.  Also, blood product transfusions are not benign.  Early utilization of this drug is likely far less expensive and harmful than massive tranfusions that often ensue.
    • The patients that are likely to qualify for TXA are incredibly ill.  The reduction in  mortality by absolute numbers may be modest, but this cohort doesn't generally do well regardless.  In an era when many other standard interventions have questionable efficacy (epinephrine in cardiac arrest, PPIs in UGIB, etc) rejection of the benefits of TXA seems in-congruent.
    • The time frame issue seems work-able, especially if TXA were implemented in the pre-hospital setting.  




    References:
    07.17.12
    by

    Direct Laryngoscopy May Be Dead – Just Not to Me

    The Gist:  Video laryngoscopy (VL) augments patient safety and is a great tool for endotracheal intubation (ETI) but trainees should likely be comfortable with both DL and VL.  There's a solid argument for Emergency Physicians to maintain DL skills while using the capabilities proffered by VL in situations to improve training and patient safety.  (As a medical student, I recognize I have minimal experience and probably should not have an opinion on this issue but, like most things, I do).  For expert airway tips and tricks, visit Life in the Fast Lane's Own the Airway.

    A couple of months back, I heard something frightening in the midst of shoulder presses at the gym - that direct laryngoscopy is dying.  On the superb Prehospital and Retrieval Medicine (PHARM) podcast, interviewee Dr. DuCanto discussed the importance of fiberoptic laryngoscopy during difficult airways.  Days later, I shuddered again, when I found that Dr. Ron Walls proclaimed DL "dead" via Twitter.  This discussion struck entirely too close to home.  

    In preparation for intubation, many attendings, upon seeing my eager, young face, steer the Glidescope in my direction.  I discovered a little bit of confidence is a dangerous thing when the airway is involved; thus, I love having this tool powered up and ready.  It's perfect for airways during chest compressions/resuscitation and many difficult airways.  Like the faithful bougie, I like to have a fiberoptic device at the bedside during an ETI.  However, it seems that many physicians think one should learn to intubate solely with video laryngoscopy but in my limited experience, I have run into occasional problems where I converted from VL to DL with immediate success.  Of note, however, I wasn't taught any specific set of skills for VL.

    Video laryngoscopy is superb in many ways.
    • It allows more than one person to visualize the airway well.  
      • This is especially valuable in training situations, allowing the trainer to give real time feedback to the trainee.  Additionally, this adds some theoretical patient protection (Although, in the age of apneic oxygenation, it probably routinely adds more trainee protection, "No, sir, that would be the gooose, try again.")  
      • Safer for some difficult airways. Again, VL allows more than one individual the opportunity to visualize the airway which, in my experience (dangerous words!),  can be helpful for team problem solving.   
    • Airway outsourcing (see EMCrit Wee:  I've always wanted a henchman/woman).  I think that most good Emergency Physicians have at least a third, if not fourth, hand tucked away somewhere.  Either that or they've mastered the art of preparation and adaptation for various procedures.  The following tasks can be outsourced, allowing the operator to keep their hands free/clutching the tube/bougie.   
      • I have a clear disdain for cricoid pressure as it has destroyed more views of the cords than it's created for me; however, laryngeal manipulation using the VL is an excellent idea, if needed.
      • Suction. Again, an assistant can direct the Yankauer to the necessary regions without getting in the way (too much, theoretically).  
      • Prepass bougie/ETT.
    • A combination VL/DL exists in the C-Mac device, which allows an intubator to use a VL view or DL view.  While I have no first hand experience with this device, studies such as this one in Anesthesia & Analgesia, look promising.  This study in BMC Anesthesiology demonstrates that the VL view resulted in faster visualization but actually required a greater number of attempts at ETI for success (perhaps due to operator familiarity/lack of training). 
    So, why am I somewhat reticent?
    • Different skill set than DL, at least to do VL correctly.  Drs. Weingart and DuCanto on EMCrit Episode 73 highlight some necessary differences to properly perform VL. 
      • The individual performing ETI should focus their gaze as such:  Mouth -> Screen -> Mouth -> Screen. 
      • Hold the ETT further back and rotate 15 degrees, using a rotatory motion of the thumb and forefinger
    • Sometimes the VL screen gets obscured by blood, secretions, or fog.  Most airways in EM are less pristine than the ones I initially trained on in the OR.  In these cases, DL may allow for quicker ETI.  
    • Passing the tube is somteimes more difficult with the Glidescope as there seems to be less space in the mouth.  Sometimes good technique can overcome this, but some studies demonstrate the ETI time isn't consistently lower in the VL group (the time to good view may be quicker, but not to cord placement).  The literature pretty consistently shows that one can achieve a technically good view in less time with VL but the time to ETI is not consistently better across studies (1,2).  
      • For example, this trial showed an average time to ETI of 22.5 sec (18-29.5) with DL compared with 33 sec (27.5-35.5) with VL (Glidescope), which was statistically significant.  This may be in part due to operator familiarity, favoring DL, but I think this point is still valid.
      • A meta-analysis in the Canadian Journal of Anesthesia demonstrated a statistically significant difference, favoring VL, in achieving a good view of the cords; however, there was no statistically significant difference in time to ETI between DL and VL. 
    • VL is a technology/electricity dependent process.   I grew up in an area of the US where natural disasters may leave a community without electricity for a month and leave buildings/one's house in ruins.  I've spent a fair amount of time in South Asia where these situations are more like a way of life.  Many areas of the world are resource limited and may have frequent power outages and limited funds for this equipment.  

    (Cox's Bazaar, Bangladesh, 2010)

    Take home?
    Best said by Dr. Seth Trueger @MDaware on Twitter:  "VL/DL = belt + suspenders. and real time training. and supervisor midaz"  

    References:


  • (1)NIFOROPOULOU P,
  • PANTAZOPOULOS
  • I, 
  • DEMESTIHA
  • T, 
  • KOUDOUNA
  •  E, 
  • XANTHOS T. 
    •  Video-laryngoscopes in the adult airway management: a topical review of the literature Acta Anaesthesiologica Scandinavica Volume 54, Issue 9, pages 1050-1061, October 2010 


  • Groeben H.
    • Expected difficult tracheal intubation: a prospective comparison of direct laryngoscopy and video laryngoscopy in 200 patients.  Br. J. Anaesth.102 (4):546-550

    Note:  I use Glidescope interchangeably with VL at times when talking about personal experience since it's the VL method I have the most experience with.  
    07.17.12
    by

    Direct Laryngoscopy May Be Dead – Just Not to Me

    The Gist:  Video laryngoscopy (VL) augments patient safety and is a great tool for endotracheal intubation (ETI) but trainees should likely be comfortable with both DL and VL.  There's a solid argument for Emergency Physicians to maintain DL skills while using the capabilities proffered by VL in situations to improve training and patient safety.  (As a medical student, I recognize I have minimal experience and probably should not have an opinion on this issue but, like most things, I do).  For expert airway tips and tricks, visit Life in the Fast Lane's Own the Airway.

    A couple of months back, I heard something frightening in the midst of shoulder presses at the gym - that direct laryngoscopy is dying.  On the superb Prehospital and Retrieval Medicine (PHARM) podcast, interviewee Dr. DuCanto discussed the importance of fiberoptic laryngoscopy during difficult airways.  Days later, I shuddered again, when I found that Dr. Ron Walls proclaimed DL "dead" via Twitter.  This discussion struck entirely too close to home.  

    In preparation for intubation, many attendings, upon seeing my eager, young face, steer the Glidescope in my direction.  I discovered a little bit of confidence is a dangerous thing when the airway is involved; thus, I love having this tool powered up and ready.  It's perfect for airways during chest compressions/resuscitation and many difficult airways.  Like the faithful bougie, I like to have a fiberoptic device at the bedside during an ETI.  However, it seems that many physicians think one should learn to intubate solely with video laryngoscopy but in my limited experience, I have run into occasional problems where I converted from VL to DL with immediate success.  Of note, however, I wasn't taught any specific set of skills for VL.

    Video laryngoscopy is superb in many ways.
    • It allows more than one person to visualize the airway well.  
      • This is especially valuable in training situations, allowing the trainer to give real time feedback to the trainee.  Additionally, this adds some theoretical patient protection (Although, in the age of apneic oxygenation, it probably routinely adds more trainee protection, "No, sir, that would be the gooose, try again.")  
      • Safer for some difficult airways. Again, VL allows more than one individual the opportunity to visualize the airway which, in my experience (dangerous words!),  can be helpful for team problem solving.   
    • Airway outsourcing (see EMCrit Wee:  I've always wanted a henchman/woman).  I think that most good Emergency Physicians have at least a third, if not fourth, hand tucked away somewhere.  Either that or they've mastered the art of preparation and adaptation for various procedures.  The following tasks can be outsourced, allowing the operator to keep their hands free/clutching the tube/bougie.   
      • I have a clear disdain for cricoid pressure as it has destroyed more views of the cords than it's created for me; however, laryngeal manipulation using the VL is an excellent idea, if needed.
      • Suction. Again, an assistant can direct the Yankauer to the necessary regions without getting in the way (too much, theoretically).  
      • Prepass bougie/ETT.
    • A combination VL/DL exists in the C-Mac device, which allows an intubator to use a VL view or DL view.  While I have no first hand experience with this device, studies such as this one in Anesthesia & Analgesia, look promising.  This study in BMC Anesthesiology demonstrates that the VL view resulted in faster visualization but actually required a greater number of attempts at ETI for success (perhaps due to operator familiarity/lack of training). 
    So, why am I somewhat reticent?
    • Different skill set than DL, at least to do VL correctly.  Drs. Weingart and DuCanto on EMCrit Episode 73 highlight some necessary differences to properly perform VL. 
      • The individual performing ETI should focus their gaze as such:  Mouth -> Screen -> Mouth -> Screen. 
      • Hold the ETT further back and rotate 15 degrees, using a rotatory motion of the thumb and forefinger
    • Sometimes the VL screen gets obscured by blood, secretions, or fog.  Most airways in EM are less pristine than the ones I initially trained on in the OR.  In these cases, DL may allow for quicker ETI.  
    • Passing the tube is somteimes more difficult with the Glidescope as there seems to be less space in the mouth.  Sometimes good technique can overcome this, but some studies demonstrate the ETI time isn't consistently lower in the VL group (the time to good view may be quicker, but not to cord placement).  The literature pretty consistently shows that one can achieve a technically good view in less time with VL but the time to ETI is not consistently better across studies (1,2).  
      • For example, this trial showed an average time to ETI of 22.5 sec (18-29.5) with DL compared with 33 sec (27.5-35.5) with VL (Glidescope), which was statistically significant.  This may be in part due to operator familiarity, favoring DL, but I think this point is still valid.
      • A meta-analysis in the Canadian Journal of Anesthesia demonstrated a statistically significant difference, favoring VL, in achieving a good view of the cords; however, there was no statistically significant difference in time to ETI between DL and VL. 
    • VL is a technology/electricity dependent process.   I grew up in an area of the US where natural disasters may leave a community without electricity for a month and leave buildings/one's house in ruins.  I've spent a fair amount of time in South Asia where these situations are more like a way of life.  Many areas of the world are resource limited and may have frequent power outages and limited funds for this equipment.  

    (Cox's Bazaar, Bangladesh, 2010)

    Take home?
    Best said by Dr. Seth Trueger @MDaware on Twitter:  "VL/DL = belt + suspenders. and real time training. and supervisor midaz"  

    References:


  • (1)NIFOROPOULOU P,
  • PANTAZOPOULOS
  • I, 
  • DEMESTIHA
  • T, 
  • KOUDOUNA
  •  E, 
  • XANTHOS T. 
    •  Video-laryngoscopes in the adult airway management: a topical review of the literature Acta Anaesthesiologica Scandinavica Volume 54, Issue 9, pages 1050-1061, October 2010 


  • Groeben H.
    • Expected difficult tracheal intubation: a prospective comparison of direct laryngoscopy and video laryngoscopy in 200 patients.  Br. J. Anaesth.102 (4):546-550

    Note:  I use Glidescope interchangeably with VL at times when talking about personal experience since it's the VL method I have the most experience with.  
    07.17.12
    by

    Direct Laryngoscopy May Be Dead – Just Not to Me

    The Gist:  Video laryngoscopy (VL) augments patient safety and is a great tool for endotracheal intubation (ETI) but trainees should likely be comfortable with both DL and VL.  There's a solid argument for Emergency Physicians to maintain DL skills while using the capabilities proffered by VL in situations to improve training and patient safety.  (As a medical student, I recognize I have minimal experience and probably should not have an opinion on this issue but, like most things, I do).  For expert airway tips and tricks, visit Life in the Fast Lane's Own the Airway.

    A couple of months back, I heard something frightening in the midst of shoulder presses at the gym - that direct laryngoscopy is dying.  On the superb Prehospital and Retrieval Medicine (PHARM) podcast, interviewee Dr. DuCanto discussed the importance of fiberoptic laryngoscopy during difficult airways.  Days later, I shuddered again, when I found that Dr. Ron Walls proclaimed DL "dead" via Twitter.  This discussion struck entirely too close to home.  

    In preparation for intubation, many attendings, upon seeing my eager, young face, steer the Glidescope in my direction.  I discovered a little bit of confidence is a dangerous thing when the airway is involved; thus, I love having this tool powered up and ready.  It's perfect for airways during chest compressions/resuscitation and many difficult airways.  Like the faithful bougie, I like to have a fiberoptic device at the bedside during an ETI.  However, it seems that many physicians think one should learn to intubate solely with video laryngoscopy but in my limited experience, I have run into occasional problems where I converted from VL to DL with immediate success.  Of note, however, I wasn't taught any specific set of skills for VL.

    Video laryngoscopy is superb in many ways.
    • It allows more than one person to visualize the airway well.  
      • This is especially valuable in training situations, allowing the trainer to give real time feedback to the trainee.  Additionally, this adds some theoretical patient protection (Although, in the age of apneic oxygenation, it probably routinely adds more trainee protection, "No, sir, that would be the gooose, try again.")  
      • Safer for some difficult airways. Again, VL allows more than one individual the opportunity to visualize the airway which, in my experience (dangerous words!),  can be helpful for team problem solving.   
    • Airway outsourcing (see EMCrit Wee:  I've always wanted a henchman/woman).  I think that most good Emergency Physicians have at least a third, if not fourth, hand tucked away somewhere.  Either that or they've mastered the art of preparation and adaptation for various procedures.  The following tasks can be outsourced, allowing the operator to keep their hands free/clutching the tube/bougie.   
      • I have a clear disdain for cricoid pressure as it has destroyed more views of the cords than it's created for me; however, laryngeal manipulation using the VL is an excellent idea, if needed.
      • Suction. Again, an assistant can direct the Yankauer to the necessary regions without getting in the way (too much, theoretically).  
      • Prepass bougie/ETT.
    • A combination VL/DL exists in the C-Mac device, which allows an intubator to use a VL view or DL view.  While I have no first hand experience with this device, studies such as this one in Anesthesia & Analgesia, look promising.  This study in BMC Anesthesiology demonstrates that the VL view resulted in faster visualization but actually required a greater number of attempts at ETI for success (perhaps due to operator familiarity/lack of training). 
    So, why am I somewhat reticent?
    • Different skill set than DL, at least to do VL correctly.  Drs. Weingart and DuCanto on EMCrit Episode 73 highlight some necessary differences to properly perform VL. 
      • The individual performing ETI should focus their gaze as such:  Mouth -> Screen -> Mouth -> Screen. 
      • Hold the ETT further back and rotate 15 degrees, using a rotatory motion of the thumb and forefinger
    • Sometimes the VL screen gets obscured by blood, secretions, or fog.  Most airways in EM are less pristine than the ones I initially trained on in the OR.  In these cases, DL may allow for quicker ETI.  
    • Passing the tube is somteimes more difficult with the Glidescope as there seems to be less space in the mouth.  Sometimes good technique can overcome this, but some studies demonstrate the ETI time isn't consistently lower in the VL group (the time to good view may be quicker, but not to cord placement).  The literature pretty consistently shows that one can achieve a technically good view in less time with VL but the time to ETI is not consistently better across studies (1,2).  
      • For example, this trial showed an average time to ETI of 22.5 sec (18-29.5) with DL compared with 33 sec (27.5-35.5) with VL (Glidescope), which was statistically significant.  This may be in part due to operator familiarity, favoring DL, but I think this point is still valid.
      • A meta-analysis in the Canadian Journal of Anesthesia demonstrated a statistically significant difference, favoring VL, in achieving a good view of the cords; however, there was no statistically significant difference in time to ETI between DL and VL. 
    • VL is a technology/electricity dependent process.   I grew up in an area of the US where natural disasters may leave a community without electricity for a month and leave buildings/one's house in ruins.  I've spent a fair amount of time in South Asia where these situations are more like a way of life.  Many areas of the world are resource limited and may have frequent power outages and limited funds for this equipment.  

    (Cox's Bazaar, Bangladesh, 2010)

    Take home?
    Best said by Dr. Seth Trueger @MDaware on Twitter:  "VL/DL = belt + suspenders. and real time training. and supervisor midaz"  

    References:


  • (1)NIFOROPOULOU P,
  • PANTAZOPOULOS
  • I, 
  • DEMESTIHA
  • T, 
  • KOUDOUNA
  •  E, 
  • XANTHOS T. 
    •  Video-laryngoscopes in the adult airway management: a topical review of the literature Acta Anaesthesiologica Scandinavica Volume 54, Issue 9, pages 1050-1061, October 2010 


  • Groeben H.
    • Expected difficult tracheal intubation: a prospective comparison of direct laryngoscopy and video laryngoscopy in 200 patients.  Br. J. Anaesth.102 (4):546-550

    Note:  I use Glidescope interchangeably with VL at times when talking about personal experience since it's the VL method I have the most experience with.  
    07.16.12
    by

    Even Fewer Central Lines? – US Guided IVs

    The Gist:  Patients in the ED often need venous access for fluid resuscitation or medication but may have poor peripheral venous access due to a myriad of reasons.  Ultrasound guided peripheral IV placement reduces the need for central venous catheters (and may also spare patients undue pain).

    Doesn't sound that exciting, why should I care?  A patient presented with the clinical picture of sepsis - febrile, hypotensive, tachycardic, headache, visual changes and a possible source of cellulitis on his leg.  It was incredibly easy to order initiation of an early goal directed protocol; however, implementation was another story since we were unable to establish venous access.  The patient was morbidly obese and clearly intravascularly depleted, as evidenced by his very collapsed IVC on US.  The IV team eventually established access, but by that point, greater than one hour had elapsed.  The patient ended up doing well, but I think would have been better served had we begun fluid resuscitation, IV antibiotics, and the battery of lab tests more quickly.  The family and the patient were frustrated by the multiple unsuccessful attempts, and all interventions were dependent upon that access (no, he did not want an intraosseous line).    

    The paper:  Au A, Rotte M, Grzybowski R, Ku B, Fields J.  Decrease in central venous catheter placement due to use of ultrasound guidance for peripheral intravenous catheters.  Am J of Emergency Medicine.  Online first 15 July 2012.

    Methods

    • 100 patients enrolled after meeting the following criteria:  after "multiple" failed peripheral attempts, nurse and physician discussed need for IV access and, if necessary, the physician attempt at external jugular placement must have been unsuccessful.  Physicians only enrolled patients who they thought would need a central venous catheter if peripheral access were unsucessful.
    • Patients then underwent attempted cannulation with a 20g with single-operator US by a resident or attending

    Results
    • 88% of US guided peripheral IVs successful, of which, 11 eventually ended up with a CVC (1 with a central line, 10 with a PICC).
      • 1 patient with a central catheter had a line infection requiring antibiotics.
    • 12% of initial US guided peripheral IVs were unsuccessful.  7 of these underwent successful US guided IV in the ED and another 4 received a central line in the ED. 
    This study builds upon other evidence that US guided IV access reduces time and number of attempts to successful cannulation (1,2, 3), although there has been a study demonstrating no difference (4).  This small study certainly has limitations:
    • Not randomized 
    • Some of the junction points in the study are subjective.  For example, patient or operator "fatigue" is variable.
    • US guided IV only performed by physicians, not nurses or technicians
    • Further attempts at standard IV access may have been abandoned earlier than usual due to availability of US (this is not a bad thing, especially from the patient perspective)
    • No standard number of attempts prior to use of US.
    Where to from here?
    • Excessive attempts on pediatric patients seems brutal and studies demonstrate US works well for IV access in this population (6).  It's a study about ultrasound so, of course, I must mention something from the Ultrasound Podcast.  These guys are offering an incredible opportunity for US IV access education under the event "Not A Pin Cushion."  Check out their personal, touching story, which will inspire one to use US for difficult IVs.  There are many local programs and resources throughout the country that promote US guided IVs by physicians and nurses.  Here's a link to some FAQ regarding nurse placement of US guided peripheral lines from the "Stone's Side" of the Ultrasound Podcast.  Get on it. 
    • There are two things I never argue "for," but I don't think this case fits either one. 
      • Procedures that encourage providers to rely upon technology.  As someone with first hand disaster experiences following natural disasters, I'm fearful of dependence on things that require being "plugged in" (being without electricity for a month will instill this in one) and of becoming lazy.  I think that US is a great adjunct in the IV process for patients who fail initial attempts, thus could serve as an augmentation aid in difficult scenarios rather than foster dependence.
      • Fewer procedures (unless it's actually in the patient's best interest, which turns out to not be infrequently).  Some patients will need a central line, period, perhaps for pressors or due to failure of peripheral access.  However, the risks associated with central lines including infection, probably the most common, are not negligible.  When indicated, central lines are still the way to go, US guided IV just reduces the number of unnecessary central lines (by up to 85% in the abovementioned study).
    If it's a family member or friend, I'm breaking out the US even earlier.


    References:
    1.  Costantino TG, Parikh AK, Satz WA, Fojtik JP.  Ultrasonography-guided peripheral intravenous access versus traditional approaches in patients with difficult intravenous access.Ann Emerg Med. 2005 Nov;46(5):456-61.
    2.  Doniger SJ, Ishimine P, Fox JC, Kanegaye JT. Randomized controlled trial of ultrasound-guided peripheral intravenous catheter placement versus traditional techniques in difficult-access pediatric patients.  Pediatr Emerg Care. 2009 Mar;25(3):154-9.
    3.  Bauman M, Braude D, Crandall C.  Ultrasound-guidance vs. standard technique in difficult vascular access patients by ED technicians.  Am J Emerg med. 2009 Feb; 27(2)135-40.
    4.  Stein J, George B, River G, Hebig A, McDermott D.  Ultrasonographically guided peripheral intravenous cannulation in emergency department patients with difficult intravenous access: a randomized trial.   2009 Jul;54(1):33-40. 
    5.  Dargin JM, Rebholz CM, Lowenstein RA, Mitchell PM, Feldman JA.  Ultrasonography-guided peripheral intravenous catheter survival in ED patients with difficult access. Am J Emerg Med. 2010 Jan;28(1):1-7.
    6.  Benkhadra M, Collignon M, Fournel I, Oeuvrard C, Rollin P, Perrin M, Volot F, Girard C.  Paediatr Anaesth. 2012 May;22(5):449-54.  Ultrasound guidance allows faster peripheral IV cannulation in children under 3 years of age with difficult venous access: a prospective randomized study.
    07.16.12
    by

    Even Fewer Central Lines? – US Guided IVs

    The Gist:  Patients in the ED often need venous access for fluid resuscitation or medication but may have poor peripheral venous access due to a myriad of reasons.  Ultrasound guided peripheral IV placement reduces the need for central venous catheters (and may also spare patients undue pain).

    Doesn't sound that exciting, why should I care?  A patient presented with the clinical picture of sepsis - febrile, hypotensive, tachycardic, headache, visual changes and a possible source of cellulitis on his leg.  It was incredibly easy to order initiation of an early goal directed protocol; however, implementation was another story since we were unable to establish venous access.  The patient was morbidly obese and clearly intravascularly depleted, as evidenced by his very collapsed IVC on US.  The IV team eventually established access, but by that point, greater than one hour had elapsed.  The patient ended up doing well, but I think would have been better served had we begun fluid resuscitation, IV antibiotics, and the battery of lab tests more quickly.  The family and the patient were frustrated by the multiple unsuccessful attempts, and all interventions were dependent upon that access (no, he did not want an intraosseous line).    

    The paper:  Au A, Rotte M, Grzybowski R, Ku B, Fields J.  Decrease in central venous catheter placement due to use of ultrasound guidance for peripheral intravenous catheters.  Am J of Emergency Medicine.  Online first 15 July 2012.

    Methods

    • 100 patients enrolled after meeting the following criteria:  after "multiple" failed peripheral attempts, nurse and physician discussed need for IV access and, if necessary, the physician attempt at external jugular placement must have been unsuccessful.  Physicians only enrolled patients who they thought would need a central venous catheter if peripheral access were unsucessful.
    • Patients then underwent attempted cannulation with a 20g with single-operator US by a resident or attending

    Results
    • 88% of US guided peripheral IVs successful, of which, 11 eventually ended up with a CVC (1 with a central line, 10 with a PICC).
      • 1 patient with a central catheter had a line infection requiring antibiotics.
    • 12% of initial US guided peripheral IVs were unsuccessful.  7 of these underwent successful US guided IV in the ED and another 4 received a central line in the ED. 
    This study builds upon other evidence that US guided IV access reduces time and number of attempts to successful cannulation (1,2, 3), although there has been a study demonstrating no difference (4).  This small study certainly has limitations:
    • Not randomized 
    • Some of the junction points in the study are subjective.  For example, patient or operator "fatigue" is variable.
    • US guided IV only performed by physicians, not nurses or technicians
    • Further attempts at standard IV access may have been abandoned earlier than usual due to availability of US (this is not a bad thing, especially from the patient perspective)
    • No standard number of attempts prior to use of US.
    Where to from here?
    • Excessive attempts on pediatric patients seems brutal and studies demonstrate US works well for IV access in this population (6).  It's a study about ultrasound so, of course, I must mention something from the Ultrasound Podcast.  These guys are offering an incredible opportunity for US IV access education under the event "Not A Pin Cushion."  Check out their personal, touching story, which will inspire one to use US for difficult IVs.  There are many local programs and resources throughout the country that promote US guided IVs by physicians and nurses.  Here's a link to some FAQ regarding nurse placement of US guided peripheral lines from the "Stone's Side" of the Ultrasound Podcast.  Get on it. 
    • There are two things I never argue "for," but I don't think this case fits either one. 
      • Procedures that encourage providers to rely upon technology.  As someone with first hand disaster experiences following natural disasters, I'm fearful of dependence on things that require being "plugged in" (being without electricity for a month will instill this in one) and of becoming lazy.  I think that US is a great adjunct in the IV process for patients who fail initial attempts, thus could serve as an augmentation aid in difficult scenarios rather than foster dependence.
      • Fewer procedures (unless it's actually in the patient's best interest, which turns out to not be infrequently).  Some patients will need a central line, period, perhaps for pressors or due to failure of peripheral access.  However, the risks associated with central lines including infection, probably the most common, are not negligible.  When indicated, central lines are still the way to go, US guided IV just reduces the number of unnecessary central lines (by up to 85% in the abovementioned study).
    If it's a family member or friend, I'm breaking out the US even earlier.


    References:
    1.  Costantino TG, Parikh AK, Satz WA, Fojtik JP.  Ultrasonography-guided peripheral intravenous access versus traditional approaches in patients with difficult intravenous access.Ann Emerg Med. 2005 Nov;46(5):456-61.
    2.  Doniger SJ, Ishimine P, Fox JC, Kanegaye JT. Randomized controlled trial of ultrasound-guided peripheral intravenous catheter placement versus traditional techniques in difficult-access pediatric patients.  Pediatr Emerg Care. 2009 Mar;25(3):154-9.
    3.  Bauman M, Braude D, Crandall C.  Ultrasound-guidance vs. standard technique in difficult vascular access patients by ED technicians.  Am J Emerg med. 2009 Feb; 27(2)135-40.
    4.  Stein J, George B, River G, Hebig A, McDermott D.  Ultrasonographically guided peripheral intravenous cannulation in emergency department patients with difficult intravenous access: a randomized trial.   2009 Jul;54(1):33-40. 
    5.  Dargin JM, Rebholz CM, Lowenstein RA, Mitchell PM, Feldman JA.  Ultrasonography-guided peripheral intravenous catheter survival in ED patients with difficult access. Am J Emerg Med. 2010 Jan;28(1):1-7.
    6.  Benkhadra M, Collignon M, Fournel I, Oeuvrard C, Rollin P, Perrin M, Volot F, Girard C.  Paediatr Anaesth. 2012 May;22(5):449-54.  Ultrasound guidance allows faster peripheral IV cannulation in children under 3 years of age with difficult venous access: a prospective randomized study.
    07.16.12
    by

    Even Fewer Central Lines? – US Guided IVs

    The Gist:  Patients in the ED often need venous access for fluid resuscitation or medication but may have poor peripheral venous access due to a myriad of reasons.  Ultrasound guided peripheral IV placement reduces the need for central venous catheters (and may also spare patients undue pain).

    Doesn't sound that exciting, why should I care?  A patient presented with the clinical picture of sepsis - febrile, hypotensive, tachycardic, headache, visual changes and a possible source of cellulitis on his leg.  It was incredibly easy to order initiation of an early goal directed protocol; however, implementation was another story since we were unable to establish venous access.  The patient was morbidly obese and clearly intravascularly depleted, as evidenced by his very collapsed IVC on US.  The IV team eventually established access, but by that point, greater than one hour had elapsed.  The patient ended up doing well, but I think would have been better served had we begun fluid resuscitation, IV antibiotics, and the battery of lab tests more quickly.  The family and the patient were frustrated by the multiple unsuccessful attempts, and all interventions were dependent upon that access (no, he did not want an intraosseous line).    

    The paper:  Au A, Rotte M, Grzybowski R, Ku B, Fields J.  Decrease in central venous catheter placement due to use of ultrasound guidance for peripheral intravenous catheters.  Am J of Emergency Medicine.  Online first 15 July 2012.

    Methods

    • 100 patients enrolled after meeting the following criteria:  after "multiple" failed peripheral attempts, nurse and physician discussed need for IV access and, if necessary, the physician attempt at external jugular placement must have been unsuccessful.  Physicians only enrolled patients who they thought would need a central venous catheter if peripheral access were unsucessful.
    • Patients then underwent attempted cannulation with a 20g with single-operator US by a resident or attending

    Results
    • 88% of US guided peripheral IVs successful, of which, 11 eventually ended up with a CVC (1 with a central line, 10 with a PICC).
      • 1 patient with a central catheter had a line infection requiring antibiotics.
    • 12% of initial US guided peripheral IVs were unsuccessful.  7 of these underwent successful US guided IV in the ED and another 4 received a central line in the ED. 
    This study builds upon other evidence that US guided IV access reduces time and number of attempts to successful cannulation (1,2, 3), although there has been a study demonstrating no difference (4).  This small study certainly has limitations:
    • Not randomized 
    • Some of the junction points in the study are subjective.  For example, patient or operator "fatigue" is variable.
    • US guided IV only performed by physicians, not nurses or technicians
    • Further attempts at standard IV access may have been abandoned earlier than usual due to availability of US (this is not a bad thing, especially from the patient perspective)
    • No standard number of attempts prior to use of US.
    Where to from here?
    • Excessive attempts on pediatric patients seems brutal and studies demonstrate US works well for IV access in this population (6).  It's a study about ultrasound so, of course, I must mention something from the Ultrasound Podcast.  These guys are offering an incredible opportunity for US IV access education under the event "Not A Pin Cushion."  Check out their personal, touching story, which will inspire one to use US for difficult IVs.  There are many local programs and resources throughout the country that promote US guided IVs by physicians and nurses.  Here's a link to some FAQ regarding nurse placement of US guided peripheral lines from the "Stone's Side" of the Ultrasound Podcast.  Get on it. 
    • There are two things I never argue "for," but I don't think this case fits either one. 
      • Procedures that encourage providers to rely upon technology.  As someone with first hand disaster experiences following natural disasters, I'm fearful of dependence on things that require being "plugged in" (being without electricity for a month will instill this in one) and of becoming lazy.  I think that US is a great adjunct in the IV process for patients who fail initial attempts, thus could serve as an augmentation aid in difficult scenarios rather than foster dependence.
      • Fewer procedures (unless it's actually in the patient's best interest, which turns out to not be infrequently).  Some patients will need a central line, period, perhaps for pressors or due to failure of peripheral access.  However, the risks associated with central lines including infection, probably the most common, are not negligible.  When indicated, central lines are still the way to go, US guided IV just reduces the number of unnecessary central lines (by up to 85% in the abovementioned study).
    If it's a family member or friend, I'm breaking out the US even earlier.


    References:
    1.  Costantino TG, Parikh AK, Satz WA, Fojtik JP.  Ultrasonography-guided peripheral intravenous access versus traditional approaches in patients with difficult intravenous access.Ann Emerg Med. 2005 Nov;46(5):456-61.
    2.  Doniger SJ, Ishimine P, Fox JC, Kanegaye JT. Randomized controlled trial of ultrasound-guided peripheral intravenous catheter placement versus traditional techniques in difficult-access pediatric patients.  Pediatr Emerg Care. 2009 Mar;25(3):154-9.
    3.  Bauman M, Braude D, Crandall C.  Ultrasound-guidance vs. standard technique in difficult vascular access patients by ED technicians.  Am J Emerg med. 2009 Feb; 27(2)135-40.
    4.  Stein J, George B, River G, Hebig A, McDermott D.  Ultrasonographically guided peripheral intravenous cannulation in emergency department patients with difficult intravenous access: a randomized trial.   2009 Jul;54(1):33-40. 
    5.  Dargin JM, Rebholz CM, Lowenstein RA, Mitchell PM, Feldman JA.  Ultrasonography-guided peripheral intravenous catheter survival in ED patients with difficult access. Am J Emerg Med. 2010 Jan;28(1):1-7.
    6.  Benkhadra M, Collignon M, Fournel I, Oeuvrard C, Rollin P, Perrin M, Volot F, Girard C.  Paediatr Anaesth. 2012 May;22(5):449-54.  Ultrasound guidance allows faster peripheral IV cannulation in children under 3 years of age with difficult venous access: a prospective randomized study.
    07.12.12
    by

    The Numbers Don’t Add Up – Selectively Using Statistics

    The Gist:  Patient safety is of the utmost importance in medicine, yet it lies in a very delicate balance with physician and student training.  Recently, it seems as though the literature suggests we should be doing fewer procedures, or at least - safer procedures.  These efforts to perform clinically significant interventions (aka smart medicine) on patients could mean fewer procedures (and thus, less practice for trainees).  Simulation is an excellent and crucial part of training, as evidenced in lumbar puncture in this article from Neurology.  However, as these articles by Tun, et al and Meguerdichian et al in July 2012 Annals of EM show, clinical situations often deviate from the more "clean" simulated endeavors.

    Recently, I had a patient who presented just over 6 hours after the onset of  a severe headache.  The patient's blood pressure was elevated to a systolic of 180 mmHg and the headache, though gradual in onset, was different in character than prior headaches.  After only partial response to a migraine cocktail, we decided to send the patient for a head CT, though subarachnoid hemorrhage (SAH) seemed unlikely.  After a clean scan, I talked with my attending.  Every ounce of clinical gestalt I have (or the sole ounce, as is likely the case) prompted me to plan to amp up the analgesia from acetaminophen, reassess, and then discharge.  This seemed like a classic migraine and the patient's neuro exam continued to be perfect.  In my plan, I mentioned that one could consider a lumbar puncture (LP) but the odds that this would result in a clinically important outcome were minimal.

    Fortunately, my attending realized the grave blunder I had made as a medical student and offered to stay late with me and do the LP, if I wanted to do one.  I had nearly talked myself and my attending out of a procedure - unthinkable for a procedure junky!  When presenting the options to the patient, I couldn't help but feel we were slightly paternalistic.  We presented solid evidence and advised the patient that we doubted that the LP would yield anything; however, we didn't quote the magnitude to which to which it was unlikely we would find something (probably <0.2%).  However, I had a bout of inner turmoil, knowing that the test would likely yield nothing besides a pair of slightly more experienced young hands and a very happy medical student.  As it turns out, the tap was clean, the patient tolerated the procedure excellently, and I felt gratitude towards the patient and more confident in my abilities

    What's the deal with lumbar punctures?   We still get to stick the febrile infants, the encephalopathic (see anecdote below*), and the visibly sick headache patients with a higher pre-test probability of serious pathology; however, there's presently some controversy regarding LP in CT negative headaches.  
    • This paper, published in the BMJ, kicked off much of this controversy last August.  It demonstrated that third generation CT scanners had a sensitivity of 100% in the cohort scanned within 6 hours of headache onset, although not all negative CT scans were followed up with an LP (rather, they used 6 month clinical follow up).  The sensitivity was less in the group with negative CT scans greater than 6 hours after onset, as the blood diffuses ans and hemolyzes, obscuring the difference between CSF and blood.  
    • Drs. David Newman and Ashley Shreves dive into the world of subarachnoid hemorrhage in this podcast.  In analyzing the data, they end up determining that, in patients presenting to the ED with a headache and a negative head CT, LP will likely benefit 1 in 625..probably not worth it for most patients.  Sinai EM Media Site has a lovely cheat sheet of the basic derivations (helpful while following along with the podcast).
    • Note:  AHA guidelines still recommend LP if CT scan negative.
    * A month or so ago, I was working up a patient for altered mental status.  CT was fairly clean and the patient struck the attending as a likely drug abuser, based on dentition and other factors.  I proposed an LP, which my attending agreed to when the patient's drug screen came back negative.  Finding?  Meningitis.  Moral of the story:  Use your clinical gestalt and the evidence to guide decision making.  In the words of Dr. Mark Crislip of Gobbets o' Pus fame, "the plural of anecdote is not data."  
    07.12.12
    by

    The Numbers Don’t Add Up – Selectively Using Statistics

    The Gist:  Patient safety is of the utmost importance in medicine, yet it lies in a very delicate balance with physician and student training.  Recently, it seems as though the literature suggests we should be doing fewer procedures, or at least - safer procedures.  These efforts to perform clinically significant interventions (aka smart medicine) on patients could mean fewer procedures (and thus, less practice for trainees).  Simulation is an excellent and crucial part of training, as evidenced in lumbar puncture in this article from Neurology.  However, as these articles by Tun, et al and Meguerdichian et al in July 2012 Annals of EM show, clinical situations often deviate from the more "clean" simulated endeavors.

    Recently, I had a patient who presented just over 6 hours after the onset of  a severe headache.  The patient's blood pressure was elevated to a systolic of 180 mmHg and the headache, though gradual in onset, was different in character than prior headaches.  After only partial response to a migraine cocktail, we decided to send the patient for a head CT, though subarachnoid hemorrhage (SAH) seemed unlikely.  After a clean scan, I talked with my attending.  Every ounce of clinical gestalt I have (or the sole ounce, as is likely the case) prompted me to plan to amp up the analgesia from acetaminophen, reassess, and then discharge.  This seemed like a classic migraine and the patient's neuro exam continued to be perfect.  In my plan, I mentioned that one could consider a lumbar puncture (LP) but the odds that this would result in a clinically important outcome were minimal.

    Fortunately, my attending realized the grave blunder I had made as a medical student and offered to stay late with me and do the LP, if I wanted to do one.  I had nearly talked myself and my attending out of a procedure - unthinkable for a procedure junky!  When presenting the options to the patient, I couldn't help but feel we were slightly paternalistic.  We presented solid evidence and advised the patient that we doubted that the LP would yield anything; however, we didn't quote the magnitude to which to which it was unlikely we would find something (probably <0.2%).  However, I had a bout of inner turmoil, knowing that the test would likely yield nothing besides a pair of slightly more experienced young hands and a very happy medical student.  As it turns out, the tap was clean, the patient tolerated the procedure excellently, and I felt gratitude towards the patient and more confident in my abilities

    What's the deal with lumbar punctures?   We still get to stick the febrile infants, the encephalopathic (see anecdote below*), and the visibly sick headache patients with a higher pre-test probability of serious pathology; however, there's presently some controversy regarding LP in CT negative headaches.  
    • This paper, published in the BMJ, kicked off much of this controversy last August.  It demonstrated that third generation CT scanners had a sensitivity of 100% in the cohort scanned within 6 hours of headache onset, although not all negative CT scans were followed up with an LP (rather, they used 6 month clinical follow up).  The sensitivity was less in the group with negative CT scans greater than 6 hours after onset, as the blood diffuses ans and hemolyzes, obscuring the difference between CSF and blood.  
    • Drs. David Newman and Ashley Shreves dive into the world of subarachnoid hemorrhage in this podcast.  In analyzing the data, they end up determining that, in patients presenting to the ED with a headache and a negative head CT, LP will likely benefit 1 in 625..probably not worth it for most patients.  Sinai EM Media Site has a lovely cheat sheet of the basic derivations (helpful while following along with the podcast).
    • Note:  AHA guidelines still recommend LP if CT scan negative.
    * A month or so ago, I was working up a patient for altered mental status.  CT was fairly clean and the patient struck the attending as a likely drug abuser, based on dentition and other factors.  I proposed an LP, which my attending agreed to when the patient's drug screen came back negative.  Finding?  Meningitis.  Moral of the story:  Use your clinical gestalt and the evidence to guide decision making.  In the words of Dr. Mark Crislip of Gobbets o' Pus fame, "the plural of anecdote is not data."  
    07.12.12
    by

    The Numbers Don’t Add Up – Selectively Using Statistics

    The Gist:  Patient safety is of the utmost importance in medicine, yet it lies in a very delicate balance with physician and student training.  Recently, it seems as though the literature suggests we should be doing fewer procedures, or at least - safer procedures.  These efforts to perform clinically significant interventions (aka smart medicine) on patients could mean fewer procedures (and thus, less practice for trainees).  Simulation is an excellent and crucial part of training, as evidenced in lumbar puncture in this article from Neurology.  However, as these articles by Tun, et al and Meguerdichian et al in July 2012 Annals of EM show, clinical situations often deviate from the more "clean" simulated endeavors.

    Recently, I had a patient who presented just over 6 hours after the onset of  a severe headache.  The patient's blood pressure was elevated to a systolic of 180 mmHg and the headache, though gradual in onset, was different in character than prior headaches.  After only partial response to a migraine cocktail, we decided to send the patient for a head CT, though subarachnoid hemorrhage (SAH) seemed unlikely.  After a clean scan, I talked with my attending.  Every ounce of clinical gestalt I have (or the sole ounce, as is likely the case) prompted me to plan to amp up the analgesia from acetaminophen, reassess, and then discharge.  This seemed like a classic migraine and the patient's neuro exam continued to be perfect.  In my plan, I mentioned that one could consider a lumbar puncture (LP) but the odds that this would result in a clinically important outcome were minimal.

    Fortunately, my attending realized the grave blunder I had made as a medical student and offered to stay late with me and do the LP, if I wanted to do one.  I had nearly talked myself and my attending out of a procedure - unthinkable for a procedure junky!  When presenting the options to the patient, I couldn't help but feel we were slightly paternalistic.  We presented solid evidence and advised the patient that we doubted that the LP would yield anything; however, we didn't quote the magnitude to which to which it was unlikely we would find something (probably <0.2%).  However, I had a bout of inner turmoil, knowing that the test would likely yield nothing besides a pair of slightly more experienced young hands and a very happy medical student.  As it turns out, the tap was clean, the patient tolerated the procedure excellently, and I felt gratitude towards the patient and more confident in my abilities

    What's the deal with lumbar punctures?   We still get to stick the febrile infants, the encephalopathic (see anecdote below*), and the visibly sick headache patients with a higher pre-test probability of serious pathology; however, there's presently some controversy regarding LP in CT negative headaches.  
    • This paper, published in the BMJ, kicked off much of this controversy last August.  It demonstrated that third generation CT scanners had a sensitivity of 100% in the cohort scanned within 6 hours of headache onset, although not all negative CT scans were followed up with an LP (rather, they used 6 month clinical follow up).  The sensitivity was less in the group with negative CT scans greater than 6 hours after onset, as the blood diffuses ans and hemolyzes, obscuring the difference between CSF and blood.  
    • Drs. David Newman and Ashley Shreves dive into the world of subarachnoid hemorrhage in this podcast.  In analyzing the data, they end up determining that, in patients presenting to the ED with a headache and a negative head CT, LP will likely benefit 1 in 625..probably not worth it for most patients.  Sinai EM Media Site has a lovely cheat sheet of the basic derivations (helpful while following along with the podcast).
    • Note:  AHA guidelines still recommend LP if CT scan negative.
    * A month or so ago, I was working up a patient for altered mental status.  CT was fairly clean and the patient struck the attending as a likely drug abuser, based on dentition and other factors.  I proposed an LP, which my attending agreed to when the patient's drug screen came back negative.  Finding?  Meningitis.  Moral of the story:  Use your clinical gestalt and the evidence to guide decision making.  In the words of Dr. Mark Crislip of Gobbets o' Pus fame, "the plural of anecdote is not data."  
    07.08.12
    by

    Do We Know What We’re (not) Talking About?

    The Gist:  Providers often don't discuss the risks of diagnostic medical imaging with patients (but, according to the study referenced below, Emergency Physicians are likely leaders in this field).  Medical students and physicians seem to feel uncomfortable discussing risks of ionizing radiation with patients...educate yourself by listening to SMART EM's CT Consent podcast and your patients using these bedside aids - card from Academic Life in EM and this risk calculator!

    The paper:  Patient and Health Care Provider Discussions About the Risks of Medical Imaging: Not Ready for Prime Time  Stickrath C, Druck J, Hensley N, Maddox T, Richlie R. Arch Intern Med. 2012;():1-2. doi:10.1001/archinternmed.2012.1791

    Methods:
    • E-mail questionnaire to providers (4th year medical students, residents, attendings) at public university
    Results:
    • Low response rate (41%) to get n=348 (not all surveys returned were complete so some of the numbers for individual variables were <348)
    • Most respondents (71%) reported discussing radiation risk of imaging with patients less than 1/4 of the time.
    • EM residents and 4th year medical students only group that at least half of respondents reported discussing radiation risk with patients at least half the time. n=40 medical students and 33 residents, so a small sampling.
    • Over half of respondents reported never mentioning the possibility of incidental findings on scans
    • Only 27% (81 of 300) of providers felt comfortable educating patients on the risk of ionizing radiation from imaging 
    What's the deal?
    • Providers are limited by time and extremely variable degrees of health literacy in the patient population.  In EM, critically ill patients, including trauma patients, may not be responsive (able to participate in the conversation) and may not have the critical time for discussion.  Consider engaging the high risk medical patients, those with renal colic, chronic abdominal pain, etc, in conversations regarding the risk of imaging.
    • The lack of provider comfortableness in discussing risks of ionizing patients is something that can be easily changed through education and practice.  A balance exists in which one seeks to inform the patient and reduce potential harms without scaring the patient out of necessary imaging.  
    • The information stemming from this article mostly revolves around radiation, but there are certainly other issues with imaging such as: 
      • Contrast induced nephropathy (CIN). For more on this, check out the CT consent podcast from SMART EM and this super quick segment on Keeping Up With EM from Vanderbilt. Basically, CIN is caused by renal vasocontriction and tubular injury and has a reported variable incidence from 0-50%.  Risk factors include: renal insufficiency (Cr >1.5), diabetic nephropathy, reduced renal perfusion  (heart failure, hypovolemia, etc), PCI, lots of contrast (1).
      • Incidental findings.  These can cause problems in two ways.  First, it's easy to get lured into thinking that a finding on a scan is the cause of a patient's ailment or, alternatively, that a clean scan means that there's no organic cause for the ailment.  This may cause one to miss the actual problem.  Secondly, patients may become excessively concerned over anatomic variants picked up on a scan.  I will never forget a patient, status-post MVC with surgery to fix multiple fractures, clutching a CT report, frightened about the cyst (physiologic) on her kidney. 
    I want to be able to initiate these conversations with patients.  Me too, that's why there are more resources on how to educate oneself for these conversations (and some links to bedside aids) here
    References:
    1.  Rudnick M, Tumlin J.  Pathogenesis, clinical features, and diagnosis of contrast-induced nephropathy.  UpToDate.  May 2012
    07.08.12
    by

    Do We Know What We’re (not) Talking About?

    The Gist:  Providers often don't discuss the risks of diagnostic medical imaging with patients (but, according to the study referenced below, Emergency Physicians are likely leaders in this field).  Medical students and physicians seem to feel uncomfortable discussing risks of ionizing radiation with patients...educate yourself by listening to SMART EM's CT Consent podcast and your patients using these bedside aids - card from Academic Life in EM and this risk calculator!

    The paper:  Patient and Health Care Provider Discussions About the Risks of Medical Imaging: Not Ready for Prime Time  Stickrath C, Druck J, Hensley N, Maddox T, Richlie R. Arch Intern Med. 2012;():1-2. doi:10.1001/archinternmed.2012.1791

    Methods:
    • E-mail questionnaire to providers (4th year medical students, residents, attendings) at public university
    Results:
    • Low response rate (41%) to get n=348 (not all surveys returned were complete so some of the numbers for individual variables were <348)
    • Most respondents (71%) reported discussing radiation risk of imaging with patients less than 1/4 of the time.
    • EM residents and 4th year medical students only group that at least half of respondents reported discussing radiation risk with patients at least half the time. n=40 medical students and 33 residents, so a small sampling.
    • Over half of respondents reported never mentioning the possibility of incidental findings on scans
    • Only 27% (81 of 300) of providers felt comfortable educating patients on the risk of ionizing radiation from imaging 
    What's the deal?
    • Providers are limited by time and extremely variable degrees of health literacy in the patient population.  In EM, critically ill patients, including trauma patients, may not be responsive (able to participate in the conversation) and may not have the critical time for discussion.  Consider engaging the high risk medical patients, those with renal colic, chronic abdominal pain, etc, in conversations regarding the risk of imaging.
    • The lack of provider comfortableness in discussing risks of ionizing patients is something that can be easily changed through education and practice.  A balance exists in which one seeks to inform the patient and reduce potential harms without scaring the patient out of necessary imaging.  
    • The information stemming from this article mostly revolves around radiation, but there are certainly other issues with imaging such as: 
      • Contrast induced nephropathy (CIN). For more on this, check out the CT consent podcast from SMART EM and this super quick segment on Keeping Up With EM from Vanderbilt. Basically, CIN is caused by renal vasocontriction and tubular injury and has a reported variable incidence from 0-50%.  Risk factors include: renal insufficiency (Cr >1.5), diabetic nephropathy, reduced renal perfusion  (heart failure, hypovolemia, etc), PCI, lots of contrast (1).
      • Incidental findings.  These can cause problems in two ways.  First, it's easy to get lured into thinking that a finding on a scan is the cause of a patient's ailment or, alternatively, that a clean scan means that there's no organic cause for the ailment.  This may cause one to miss the actual problem.  Secondly, patients may become excessively concerned over anatomic variants picked up on a scan.  I will never forget a patient, status-post MVC with surgery to fix multiple fractures, clutching a CT report, frightened about the cyst (physiologic) on her kidney. 
    I want to be able to initiate these conversations with patients.  Me too, that's why there are more resources on how to educate oneself for these conversations (and some links to bedside aids) here
    References:
    1.  Rudnick M, Tumlin J.  Pathogenesis, clinical features, and diagnosis of contrast-induced nephropathy.  UpToDate.  May 2012
    07.08.12
    by

    Do We Know What We’re (not) Talking About?

    The Gist:  Providers often don't discuss the risks of diagnostic medical imaging with patients (but, according to the study referenced below, Emergency Physicians are likely leaders in this field).  Medical students and physicians seem to feel uncomfortable discussing risks of ionizing radiation with patients...educate yourself by listening to SMART EM's CT Consent podcast and your patients using these bedside aids - card from Academic Life in EM and this risk calculator!

    The paper:  Patient and Health Care Provider Discussions About the Risks of Medical Imaging: Not Ready for Prime Time  Stickrath C, Druck J, Hensley N, Maddox T, Richlie R. Arch Intern Med. 2012;():1-2. doi:10.1001/archinternmed.2012.1791

    Methods:
    • E-mail questionnaire to providers (4th year medical students, residents, attendings) at public university
    Results:
    • Low response rate (41%) to get n=348 (not all surveys returned were complete so some of the numbers for individual variables were <348)
    • Most respondents (71%) reported discussing radiation risk of imaging with patients less than 1/4 of the time.
    • EM residents and 4th year medical students only group that at least half of respondents reported discussing radiation risk with patients at least half the time. n=40 medical students and 33 residents, so a small sampling.
    • Over half of respondents reported never mentioning the possibility of incidental findings on scans
    • Only 27% (81 of 300) of providers felt comfortable educating patients on the risk of ionizing radiation from imaging 
    What's the deal?
    • Providers are limited by time and extremely variable degrees of health literacy in the patient population.  In EM, critically ill patients, including trauma patients, may not be responsive (able to participate in the conversation) and may not have the critical time for discussion.  Consider engaging the high risk medical patients, those with renal colic, chronic abdominal pain, etc, in conversations regarding the risk of imaging.
    • The lack of provider comfortableness in discussing risks of ionizing patients is something that can be easily changed through education and practice.  A balance exists in which one seeks to inform the patient and reduce potential harms without scaring the patient out of necessary imaging.  
    • The information stemming from this article mostly revolves around radiation, but there are certainly other issues with imaging such as: 
      • Contrast induced nephropathy (CIN). For more on this, check out the CT consent podcast from SMART EM and this super quick segment on Keeping Up With EM from Vanderbilt. Basically, CIN is caused by renal vasocontriction and tubular injury and has a reported variable incidence from 0-50%.  Risk factors include: renal insufficiency (Cr >1.5), diabetic nephropathy, reduced renal perfusion  (heart failure, hypovolemia, etc), PCI, lots of contrast (1).
      • Incidental findings.  These can cause problems in two ways.  First, it's easy to get lured into thinking that a finding on a scan is the cause of a patient's ailment or, alternatively, that a clean scan means that there's no organic cause for the ailment.  This may cause one to miss the actual problem.  Secondly, patients may become excessively concerned over anatomic variants picked up on a scan.  I will never forget a patient, status-post MVC with surgery to fix multiple fractures, clutching a CT report, frightened about the cyst (physiologic) on her kidney. 
    I want to be able to initiate these conversations with patients.  Me too, that's why there are more resources on how to educate oneself for these conversations (and some links to bedside aids) here
    References:
    1.  Rudnick M, Tumlin J.  Pathogenesis, clinical features, and diagnosis of contrast-induced nephropathy.  UpToDate.  May 2012
    07.03.12
    by

    Out of Control: CT Scans in Renal Colic

    The Gist:   Patient's don't keep track of their imaging and often underestimate the amount of radiation they've been exposed to through medical imaging.  Renal colic patients are at a high risk of cumulative radiation exposure so consider beginning the diagnostic evaluation other modalities, such as renal ultrasound (US), in relatively high risk populations.  CT scans aren't bad, but should probably used in series after US and with consideration.

    Who should I really worry about?  If the imaging is absolutely necessary, then a theorized risk doesn't outweigh the potential harm from not performing the scan.  Period.  Also, younger people are more radiosensitive so imaging the geriatric population is less of an issue from the radiation standpoint.  For a review of radiation in medical imaging, check this out.

    Patients with multiple medical problems.  Many patients, if not most patients, have no idea how much imaging they've had.  A study by Baumann et al in Annals of EM surveyed patients regarding their perception of radiation in medical imaging.  
    • In this study (n=1,168), 365 of participants reported no previous CT scan, of these 39% had at least one documented CT scan in that medical system (2). As radiation is additive, how can one estimate a patient's radiation risk with no idea of exposure?  
    Patients with renal colic.  Presently, the "gold standard" diagnostic modality for renal colic exists as the CT scan.  A retrospective chart review published by Broder, et al provides insight into the magnitude of the problem of radiation exposure in evaluation of 356 patient encounters (n=306 patients) for suspected renal colic over 10 month period.   
    • 74% got a CT (n=262)
    • Many got more than one CT scan in that period:
      • Nearly half of the patients (49.3%, n=151) had 2 CT scans during the time period
      • 15% had 3 CT scans (n=46) 
      • 4.9% had 4 CT scans (n=15) 
      • 1% (n=3) had 7 CT scans
      • 1.6% (n=5) had >9 CT scans
    • Three patients had excessive scans:  28 y/o female had 14 CTs, a 53 y/o male had 25 CT scans, and a 42 y/o female had 22 CT scans. 
      • 38% of CTs were normal and only 2% (6 scans) showed an urgent or emergent cause of symptoms
      • 21% (n=56) of CT scans showed complicated urolithiasis
      • Only 6% of those who had a CT scan underwent a procedure
      A typical single detector unenhanced CT in suspected renal colic exposes a patient to approximately 6.5 mSv (8.5 mSv for multidetector unenhanced CT) (3).  For simplicity sake, suppose scans were single detector CT limited protocol (not complete abdomen/pelvis scans) then the cumulative dose for some of the patients reached near 50 mSv.  If there's a 1 in 1000 risk of cancer caused by radiation per 10 mSv, then at least half of the patients in this cohort tip that balance.  Some of the patients received over 100 mSv of radiation within this short time frame.  Additionally, the mean age in this study was 38.9 years, placing these patients in a more radiosensitive category than their geriatric peers.

      Also, keep in mind that the above Broder, et al study was conducted in 2003.  Another review, published in Academic Emergency Medicine demonstrated that between 1996-2007, CT usage for flank pain 4% to 42.5%, a 10-fold increase.  Thus, the Broder study may actually underestimate the radiation exposure for this population.  Unfortunately, this increase didn't result in an increase in the diagnosis of the badness that emergency physicians look for (therefore, likely not imparting a significant patient benefit) (1).

      There is a solution...ultrasound and common sense.  For the former, Mike and Matt come through on Ultrasound Podcast, a podcast filled with great visual examples of hydronephrosis for practice. SonoSpot, a relatively new blog, also has a great entry on renal ultrasound.
      • Curvilinear or phased array low frequency probe 
      • Placing the probe in the right and left mid-axillary line at the lower rib cage
      • Slowly fan up and down to evaluate the longitudinal view of the kidney for dilation of the collecting system and renal pelvis
      • Rotate 90 degrees to see the transverse view of the kidneys and slowly fan
      • Look at the bladder
      • Consider administering a 500 mL bolus of fluid before US
      • Add an aorta US in older patients with higher suspicion for AAA
      • Do a U/A
      • Get a CT if needed
      I'm looking...how do I interpret what I see?  The name of the game is hydronephrosis, which correlates to nephrolithiasis as stones are poorly visualized in US.
      • Sensitivity 73-97%; Specificity 73-83%
      • Study with highest sensitivity administered 500 mL fluid bolus prior to US
      The statistics listed below are from an excellent review article (abstract here). 
      Mild: renal pelvis dilation.
      • 88% stones < 5 mm (95% CI 79.2-92.3).  Almost all of these stones pass spontaneously (76.7%)
      • Treat clinically and D/C with follow up if improved.
      • If fail medical management, get CT scan
      Moderate: renal pelvis and calyces dilated
      • 69.8%  stones <5 mm (95% CI 54.9-81.4)
      • Consider treating clinically and D/C with follow up if improved.
      • If fail medical management, get CT scan.
      Severe hydronephrosis: effacement of entire collecting system
      • 80%  stones > 5mm (95% CI 37.6-96.4).  These stones are less likely to pass spontaneously. 
      • CT scan/urology consult  
      1.  Westphalen A,
      2.  Hsia R, 
      3. Maselli J, 
      4. Wang R, 
      5. Gonzales R.  
        6. Radiological Imaging of Patients With Suspected Urinary Tract Stones: National Trends, Diagnoses, and Predictors Academic Emergency Medicine Volume 18, Issue 7, pages 699-707, July 2011
      1. Howard P. Forman.  
        2. Radiation Dose Associated with Unenhanced CT for Suspected Renal Colic: Impact of Repetitive Studies AJR Am J Roentgenol. 2006 Apr;186(4):1120-4.
      07.03.12
      by

      Out of Control: CT Scans in Renal Colic

      The Gist:   Patient's don't keep track of their imaging and often underestimate the amount of radiation they've been exposed to through medical imaging.  Renal colic patients are at a high risk of cumulative radiation exposure so consider beginning the diagnostic evaluation other modalities, such as renal ultrasound (US), in relatively high risk populations.  CT scans aren't bad, but should probably used in series after US and with consideration.

      Who should I really worry about?  If the imaging is absolutely necessary, then a theorized risk doesn't outweigh the potential harm from not performing the scan.  Period.  Also, younger people are more radiosensitive so imaging the geriatric population is less of an issue from the radiation standpoint.  For a review of radiation in medical imaging, check this out.

      Patients with multiple medical problems.  Many patients, if not most patients, have no idea how much imaging they've had.  A study by Baumann et al in Annals of EM surveyed patients regarding their perception of radiation in medical imaging.  
      • In this study (n=1,168), 365 of participants reported no previous CT scan, of these 39% had at least one documented CT scan in that medical system (2). As radiation is additive, how can one estimate a patient's radiation risk with no idea of exposure?  
      Patients with renal colic.  Presently, the "gold standard" diagnostic modality for renal colic exists as the CT scan.  A retrospective chart review published by Broder, et al provides insight into the magnitude of the problem of radiation exposure in evaluation of 356 patient encounters (n=306 patients) for suspected renal colic over 10 month period.   
      • 74% got a CT (n=262)
      • Many got more than one CT scan in that period:
        • Nearly half of the patients (49.3%, n=151) had 2 CT scans during the time period
        • 15% had 3 CT scans (n=46) 
        • 4.9% had 4 CT scans (n=15) 
        • 1% (n=3) had 7 CT scans
        • 1.6% (n=5) had >9 CT scans
      • Three patients had excessive scans:  28 y/o female had 14 CTs, a 53 y/o male had 25 CT scans, and a 42 y/o female had 22 CT scans. 
        • 38% of CTs were normal and only 2% (6 scans) showed an urgent or emergent cause of symptoms
        • 21% (n=56) of CT scans showed complicated urolithiasis
        • Only 6% of those who had a CT scan underwent a procedure
        A typical single detector unenhanced CT in suspected renal colic exposes a patient to approximately 6.5 mSv (8.5 mSv for multidetector unenhanced CT) (3).  For simplicity sake, suppose scans were single detector CT limited protocol (not complete abdomen/pelvis scans) then the cumulative dose for some of the patients reached near 50 mSv.  If there's a 1 in 1000 risk of cancer caused by radiation per 10 mSv, then at least half of the patients in this cohort tip that balance.  Some of the patients received over 100 mSv of radiation within this short time frame.  Additionally, the mean age in this study was 38.9 years, placing these patients in a more radiosensitive category than their geriatric peers.

        Also, keep in mind that the above Broder, et al study was conducted in 2003.  Another review, published in Academic Emergency Medicine demonstrated that between 1996-2007, CT usage for flank pain 4% to 42.5%, a 10-fold increase.  Thus, the Broder study may actually underestimate the radiation exposure for this population.  Unfortunately, this increase didn't result in an increase in the diagnosis of the badness that emergency physicians look for (therefore, likely not imparting a significant patient benefit) (1).

        There is a solution...ultrasound and common sense.  For the former, Mike and Matt come through on Ultrasound Podcast, a podcast filled with great visual examples of hydronephrosis for practice. SonoSpot, a relatively new blog, also has a great entry on renal ultrasound.
        • Curvilinear or phased array low frequency probe 
        • Placing the probe in the right and left mid-axillary line at the lower rib cage
        • Slowly fan up and down to evaluate the longitudinal view of the kidney for dilation of the collecting system and renal pelvis
        • Rotate 90 degrees to see the transverse view of the kidneys and slowly fan
        • Look at the bladder
        • Consider administering a 500 mL bolus of fluid before US
        • Add an aorta US in older patients with higher suspicion for AAA
        • Do a U/A
        • Get a CT if needed
        I'm looking...how do I interpret what I see?  The name of the game is hydronephrosis, which correlates to nephrolithiasis as stones are poorly visualized in US.
        • Sensitivity 73-97%; Specificity 73-83%
        • Study with highest sensitivity administered 500 mL fluid bolus prior to US
        The statistics listed below are from an excellent review article (abstract here). 
        Mild: renal pelvis dilation.
        • 88% stones < 5 mm (95% CI 79.2-92.3).  Almost all of these stones pass spontaneously (76.7%)
        • Treat clinically and D/C with follow up if improved.
        • If fail medical management, get CT scan
        Moderate: renal pelvis and calyces dilated
        • 69.8%  stones <5 mm (95% CI 54.9-81.4)
        • Consider treating clinically and D/C with follow up if improved.
        • If fail medical management, get CT scan.
        Severe hydronephrosis: effacement of entire collecting system
        • 80%  stones > 5mm (95% CI 37.6-96.4).  These stones are less likely to pass spontaneously. 
        • CT scan/urology consult  
        1.  Westphalen A,
        2.  Hsia R, 
        3. Maselli J, 
        4. Wang R, 
        5. Gonzales R.  
          6. Radiological Imaging of Patients With Suspected Urinary Tract Stones: National Trends, Diagnoses, and Predictors Academic Emergency Medicine Volume 18, Issue 7, pages 699-707, July 2011
        1. Howard P. Forman.  
          2. Radiation Dose Associated with Unenhanced CT for Suspected Renal Colic: Impact of Repetitive Studies AJR Am J Roentgenol. 2006 Apr;186(4):1120-4.
        07.03.12
        by

        Out of Control: CT Scans in Renal Colic

        The Gist:   Patient's don't keep track of their imaging and often underestimate the amount of radiation they've been exposed to through medical imaging.  Renal colic patients are at a high risk of cumulative radiation exposure so consider beginning the diagnostic evaluation other modalities, such as renal ultrasound (US), in relatively high risk populations.  CT scans aren't bad, but should probably used in series after US and with consideration.

        Who should I really worry about?  If the imaging is absolutely necessary, then a theorized risk doesn't outweigh the potential harm from not performing the scan.  Period.  Also, younger people are more radiosensitive so imaging the geriatric population is less of an issue from the radiation standpoint.  For a review of radiation in medical imaging, check this out.

        Patients with multiple medical problems.  Many patients, if not most patients, have no idea how much imaging they've had.  A study by Baumann et al in Annals of EM surveyed patients regarding their perception of radiation in medical imaging.  
        • In this study (n=1,168), 365 of participants reported no previous CT scan, of these 39% had at least one documented CT scan in that medical system (2). As radiation is additive, how can one estimate a patient's radiation risk with no idea of exposure?  
        Patients with renal colic.  Presently, the "gold standard" diagnostic modality for renal colic exists as the CT scan.  A retrospective chart review published by Broder, et al provides insight into the magnitude of the problem of radiation exposure in evaluation of 356 patient encounters (n=306 patients) for suspected renal colic over 10 month period.   
        • 74% got a CT (n=262)
        • Many got more than one CT scan in that period:
          • Nearly half of the patients (49.3%, n=151) had 2 CT scans during the time period
          • 15% had 3 CT scans (n=46) 
          • 4.9% had 4 CT scans (n=15) 
          • 1% (n=3) had 7 CT scans
          • 1.6% (n=5) had >9 CT scans
        • Three patients had excessive scans:  28 y/o female had 14 CTs, a 53 y/o male had 25 CT scans, and a 42 y/o female had 22 CT scans. 
          • 38% of CTs were normal and only 2% (6 scans) showed an urgent or emergent cause of symptoms
          • 21% (n=56) of CT scans showed complicated urolithiasis
          • Only 6% of those who had a CT scan underwent a procedure
          A typical single detector unenhanced CT in suspected renal colic exposes a patient to approximately 6.5 mSv (8.5 mSv for multidetector unenhanced CT) (3).  For simplicity sake, suppose scans were single detector CT limited protocol (not complete abdomen/pelvis scans) then the cumulative dose for some of the patients reached near 50 mSv.  If there's a 1 in 1000 risk of cancer caused by radiation per 10 mSv, then at least half of the patients in this cohort tip that balance.  Some of the patients received over 100 mSv of radiation within this short time frame.  Additionally, the mean age in this study was 38.9 years, placing these patients in a more radiosensitive category than their geriatric peers.

          Also, keep in mind that the above Broder, et al study was conducted in 2003.  Another review, published in Academic Emergency Medicine demonstrated that between 1996-2007, CT usage for flank pain 4% to 42.5%, a 10-fold increase.  Thus, the Broder study may actually underestimate the radiation exposure for this population.  Unfortunately, this increase didn't result in an increase in the diagnosis of the badness that emergency physicians look for (therefore, likely not imparting a significant patient benefit) (1).

          There is a solution...ultrasound and common sense.  For the former, Mike and Matt come through on Ultrasound Podcast, a podcast filled with great visual examples of hydronephrosis for practice. SonoSpot, a relatively new blog, also has a great entry on renal ultrasound.
          • Curvilinear or phased array low frequency probe 
          • Placing the probe in the right and left mid-axillary line at the lower rib cage
          • Slowly fan up and down to evaluate the longitudinal view of the kidney for dilation of the collecting system and renal pelvis
          • Rotate 90 degrees to see the transverse view of the kidneys and slowly fan
          • Look at the bladder
          • Consider administering a 500 mL bolus of fluid before US
          • Add an aorta US in older patients with higher suspicion for AAA
          • Do a U/A
          • Get a CT if needed
          I'm looking...how do I interpret what I see?  The name of the game is hydronephrosis, which correlates to nephrolithiasis as stones are poorly visualized in US.
          • Sensitivity 73-97%; Specificity 73-83%
          • Study with highest sensitivity administered 500 mL fluid bolus prior to US
          The statistics listed below are from an excellent review article (abstract here). 
          Mild: renal pelvis dilation.
          • 88% stones < 5 mm (95% CI 79.2-92.3).  Almost all of these stones pass spontaneously (76.7%)
          • Treat clinically and D/C with follow up if improved.
          • If fail medical management, get CT scan
          Moderate: renal pelvis and calyces dilated
          • 69.8%  stones <5 mm (95% CI 54.9-81.4)
          • Consider treating clinically and D/C with follow up if improved.
          • If fail medical management, get CT scan.
          Severe hydronephrosis: effacement of entire collecting system
          • 80%  stones > 5mm (95% CI 37.6-96.4).  These stones are less likely to pass spontaneously. 
          • CT scan/urology consult  
          1.  Westphalen A,
          2.  Hsia R, 
          3. Maselli J, 
          4. Wang R, 
          5. Gonzales R.  
            6. Radiological Imaging of Patients With Suspected Urinary Tract Stones: National Trends, Diagnoses, and Predictors Academic Emergency Medicine Volume 18, Issue 7, pages 699-707, July 2011
          1. Howard P. Forman.  
            2. Radiation Dose Associated with Unenhanced CT for Suspected Renal Colic: Impact of Repetitive Studies AJR Am J Roentgenol. 2006 Apr;186(4):1120-4.
          06.25.12
          by

          So Rad: Radiation in Medical Imaging, The Basics

          The Gist:  Although the evidence is somewhat murky because CT scans are relatively new and the data is extrapolated from atomic bomb survivors, there is about a 1 in 1000 chance that an individual exposed to 10 mSv (1 routine abdominal CT scan) will develop cancer attributable to that CT.  How this is derived can be found below (to hear it from the experts: NEJM review article).
          Medicine is a science of uncertainty, and an art of probability. 
          -William Osler

          Radiation in medical imaging is a hot topic.  CT scans are often necessary in the Emergency Department to identify critical issues quickly, but there is a risk associated with the ionizing radiation from this imaging so it's somewhat important to have an ability to discuss this risk (cheat sheet from Academic Life In EM).

          I hear rad this, milliSievert that...what's the deal?  Some of these terms are historic in nature; most medical literature uses the Sievert (Sv).

          Most useful in medicine:
          • Sievert (Sv) - effective dose of radiation on biological tissue.  It's specifically designed to reflect the radiation risk in tissue.  This is the primary difference between a Sv and a Gy. 
            • 1 Sv= 100 rem.  We use milliSieverts in most medical imaging.
            • Neoplasms have typically been associated with radiation in excess of 50 mSv
          • Gray - amount of ionizing radiation energy absorbed by an object. Does not describe any biological effects.
            • 1 gray (Gy) = 100 rad.
            • No real direct interchangeability between Sv and Gy because the former is only applicable to biological tissue.
          Less useful/Historic:
          • 1 roentgen = unit of radiation dose.
          • REM = roentgen equivalent in man. Amount absorbed by human tissue, depending on the type of tissue.
          • RAD = radiation absorbed dose. Work of energy absorbed by 1 roentgen (amount absorbed by 1 roentgen as it affects biological tissue). Used in mostly in industry. 
          Just how much radiation are we talking about in medicine?  On average, a person receives an average background of 3-3.5 mSv by just inhabiting Earth.  

          Most dialogue on radiation risk in medical imaging centers on CT scans because they utilize far more radiation than plain x-rays.  The actual radiation from CT scans seems pretty variable based on scanned organ and the CT scanner/operator.  The Smith-Bindman, et al study published in the Archives of Int Medicine estimated the actual radiation exposure of CT scans at study institutions using the dose-length product (DLP), which is an approximation of the total energy a patient absorbs from the scan, when adjusted for organ sensitivity to radiation.  It's also important to note that radiation dose depends on the type of CT scan and the effects depend on the sensitivity of the tissue in a given anatomic area.
          • Routine abdominal CT scan estimated exposure quoted as 8-10 mSv
            • Actual calculated radiation: Average 11-20 mSv (Range 4-45 mSv) (little variation with regard to with or without contrast).  
          • Multiphase abdomen and pelvis CT scanning: median 31 mSv (Range 6-90 mSv)
          • Chest CT for suspected pulmonary embolus: median 10 mSv (Range 2-30 mSv)
          • Routine head CT median:  2-3 mSv (Range 0.3-6 mSv)

          So, how much does it take to cause harm?  
          BEIR (Biological Effects of Ionizing Radiaiton) VII Report holds that a dose dependent, linear no-threshold relationship exists between ionizing radiation and human cancers.  Basically, this means that all exposure carries a certain probability of harm with no zero-risk dose and that the effects of multiple small doses are additive.  

          The model is based on studies of the survivors of the 1945 atomic bombs in Japan.  Brenner has probably published the most popular articles translating this data into meaningful risks from medical imaging, including this paper.  The data stems from a cohort of over 120,000 individuals from the Radiation Effects Research Foundation.  A good overview of this database.  The data demonstrate:
          • ~30,000 survivors had low dose radiation exposure (5-100 mSv), approximately the same dose as many CT scans, making this cohort relevant
          • The risk of all solid cancers in this group is consistent with a linear increase in radiation dose.
            • Survivors in the dose category from 5-125 mSv (mean =34 mSv) show a significant  increase in mortality related to solid cancers (p = 0.025) (3).
          • Children are more radiosensitive than adults. The risk from exposure during fetal life, childhood and adolescence is estimated to be about 2-3 times as large as the risk during adulthood.
          • Cancers other than leukemia typically start to appear 10 years following exposure (5 years for leukemia) and the increased risk remains for the lifetime of the exposed individuals.
          Cardis et al published a 15 country retrospective cohort study of industrial employees exposed to radiation on a regular basis (mostly nuclear power, n= 407,391) essentially confirms the findings of the atomic bomb studies, demonstrating that low-dose radiation is associated with an increased risk of neoplasms. 
            • Excess relative risk, 0.97 per Sv (95% Cl 0.14-1.97, statistically significant) for all cancers excluding leukemia. This estimate corresponds to a relative risk of 1.10 for a radiation dose of 100 mSv. The excess relative risk for solid cancers was higher than the estimate for the atomic bomb survivors (0.32 per Sv, not significant).  Weakness:  As a retrospective observational study, there are several confounders, including smoking.
            • Average exposure per year = 19.7 mSv (1-2 routine abdominal CT scans)
          One of the major issues with this data is that these cancers are superimposed on a background cancer rate.  Additionally, there may be some selection bias and survivors may be more likely to have cancer listed as a diagnosis.

          Putting the pieces together:  Children and young people are at greatest risk.
          • The Academic Life In EM blog has a handy PV card of the table from an Archives of Int Medicine study that gives quick numbers to help estimate a patient's risk.  (Aka:  your risk is 1 in ____ from this single scan). 
          • This is also a great, interactive risk calculator

          Other good resources:
          Dr. Sean Fox's slides on mededmasters.com provide a great visual supplement/review of basic radiation risks from imaging.
          Interesting article:  Radiologists and Emergency Physicians Often See Radiation Risks and Benefits Differently


          Next up..why this actually matters to clinicians 


          References:

          1. Smith-Bindman R, Lipson J, Marcus R, Kim KP, Mahesh M, Gould R, Berrington de González A, Miglioretti DL.  Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer.  Arch Intern Med. 2009 Dec 14;169(22):2078-86.

          2.
        • Baumann B, Chen E, Mills A, Glaspey L, et al.  

          • Patient Perceptions of Computed Tomographic Imaging and Their Understanding of Radiation Risk and Exposure.  Annals of Emergency Medicine  Volume 58, Issue 1 , Pages 1-7.e2, July 2011

          3.  Brenner et al.  Cancer risks attributable to low doses of ionizing radiation: Assessing what we really know.  PNASvol. 100 no. 24 13761-13766