The Breaking Point – Rib Fracture Risk Stratification

The Gist:  Rib fractures are common and may be associated with significant injury and sequelae.  While rib fractures, even in elderly, don't necessitate transfer to Level I trauma centers, have a low threshold for ICU admission for aggressive pulmonary treatment and analgesia, especially in those with multiple injuries, older patients, some patients with 3+ rib fractures, inadequate pain control/pulmonary toilet, or patients with poor baseline health status (note: based on analyses of largely observational studies without controlled data on outcome differences in). Engage in shared decision making according to the patient's individual situation and check out this podcast by EAST for a Free Open Access Medical Education (FOAM) summary.

The Case: A 62 y/o male with a 50 pack year history of smoking presents as a trauma transfer to Janus General's Level I trauma center after a fall off of a horse, no loss of consciousness, GCS 15 with chest pain. BP 132/68, HR 78, O2 97% RA. He has exquisite tenderness over his right lateral chest wall, some pain and discomfort at rest, exacerbated by deep breathing and movement, and is accompanied by a chest CT scan demonstrating a mildly displaced fracture of the lateral 5th rib, non-displaced fractures of ribs 6-7th posteriorly and a tiny collection of fluid in the right base.
  • Where should I send this patient?  Home-he seems to be ok presently without significant other traumatic stigmata? The floor-his saturations are good, his pain seems to be controllable and he's not that old?  The ICU?
This case represents a common scenario encountered on my trauma surgery rotation and in the ED, and probably similar to other systems as rates of rib fractures in trauma patients reported at 10%[1].  The disposition varied based on the attendings involved and the outcomes, as I followed along for the month, were often surprising.  The initial "sick or not sick" impression didn't necessarily cut it with regards to assessment.  How might I better stratify these patients in the ED to advocate for appropriate disposition?

Risk Stratification - Why It May Matter
Rib fractures are associated with significant morbidity (30-50%) and mortality (~10%) [3,8,9].  It is clear that rib fractures can herald badness as they may signal underlying injury - pulmonary contusion, hemothorax, pneumothorax, or intra-abdominal injury [3].  Additionally, these patients are prone to develop pneumonia (on their own or after mechanical ventilation), which is associated with morbidity and mortality.  For example, a review of the literature demonstrated OR for mortality of 5.24 (95%CI 3.51–7.82) in rib fracture patients with pneumonia versus those without [4].

So, these patients present across a broad spectrum of injury severity (isolated rib fractures vs multiple traumas) and have a decent chance of not doing well, may require significant analgesia, and, depending on who you talk to can go home, to the floor, the ICU, or the OR.  As much of the morbidity/mortality is not evident immediately, risk stratifying, in the absence of a crystal ball, is important.

The breadth of literature suggests that older age is associated a worse prognosis in patients with rib fractures.  For example, this systematic review and meta-analysis found an OR of 1.98 (95%CI 1.86–2.11) for mortality in blunt chest trauma patients >65 y/o compared with younger cohorts  [4].  This makes sense as older patient often have:
  • weaker muscles of respiration
  • decreased physiologic reserve
  • less elasticity of lungs (decrease in volumes, inspiratory/expiratory forces)
  • decreased mucociliary clearance [5] 
These factors often create a great setup for pneumonia, which is associated with the aforementioned badness.   Additionally, older patients may have comorbidities that may predispose them to complications which, result in additional morbidity/mortality [6,7].

Battle et al analyzed data from a retrospective cohort of blunt chest trauma patients and found that the following co-morbidities are associated with complications from rib fractures:
  • Chronic lung disease 3.3 (95% CI 1.6–6.8) - already compromised lungs with set-up for pneumonia
  • Pre-injury anticoagulant use 2.3 (95% CI 1.1–4.8) - signifying underlying disease or propensity to develop hemothorax
  • Oxygen sat < 90% 5.0 (95% CI 1.0–25.7) - sicker patient [7]
Congestive heart failure has also been shown to be associated with an OR of 2.62 (95%CI 1.93–3.55) for mortality [4].

In addition, patients with other traumatic injuries fare worse if they also have rib fractures as they may be predisposed to thrombosis, decreased pulmonary reserve, compromised hemostasis, head injury, and foci of infection [3,4].

How about the number of rib fractures? 3? 6?
Mortality has been quoted as 19% for each rib fracture, but note that this statistic comes from a retrospective review where the OR for mortality was calculated as 1.19 for each rib fracture, with no confidence intervals reported [2].  According to EM texts, elderly patients with 6+ rib fractures should be admitted to the ICU [8,9]. A review of the literature, however, demonstrates that there's no clear answer but somewhere between 3-6 rib fractures is associated with more badness.
  • Lee et al wrote a paper proclaiming that 3+ rib fractures exists as an indication for transfer to a trauma facility.  In this data review, patients with >3 rib fractures had higher injury severity scores - a subgroup of patients with 3+ rib fractures who may benefit from trauma center care due to their potential underlying injuries and complications [10].  
    • Limitations: no outcome data. 
  • A review of the National Trauma Data Bank data demonstrated that mortality does increase with rib fractures but noted that the tipping point for mortality peaked at 6+ ribs with mortalities of 11.41% (n=1771) for 6 rib fractures, 15.03% (n=1114) for 7 rib fractures, and 34.42% (n=1994) for 8 rib fractures [3].
This paper asserts that patient's with more rib fractures are more likely to have underlying traumatic injuries, which is used as justification for a necessary Level 1 trauma center transfer.  One can assume that trauma professionals who treat a copious quantity of rib fractures may provide more targeted care to the patients, including employment of modalities such as epidural analgesia, NIV, and surgical fixation, outcome data for this is missing.  It's not clear that the patients couldn't receive intense pulmonary therapy and analgesia at other centers.

Limitation: Not all rib fractures are created equal and the number doesn't reflect the nature of the fracture, displacement, or presence of hemo/pneumothorax.
    Is it a clear algorithm?
    Just because some patients do poorly, this doesn't mean that all patients are high risk. Some patient can certainly be discharged or admitted to low acuity settings, provided they have good follow up and analgesia.  Afterall, hospitalization and medical interventions have associated complications and costs.

    Chauny et al demonstrated that in their cohort of patient with rib fractures felt well enough to be discharged from the ED, pneumonia within the first two weeks was relatively uncommon at 0.6% of study population (n=6) [11]. So, it appears that discharge is safe in some patients, even those with 3 rib fractures but this is where clinical assessment comes into play.

    • Of note, very few in cohort (n=86; 8%) had 3+ confirmed rib fractures
    • Patients followed up by emergency physicians and research physicians at 1, 2 weeks, with AP chest x-rays, and by telephone at 4, 12 weeks.  This follow up certainly is not guaranteed in a good deal of our patient population and could have led to over-calling of pneumonia or overall more aggressive care.
    • Very few patients had outcome of interest.
    Consider using an incentive spirometer to gauge inspiratory effort/volume at the bedside as part of assessing how the rib fractures may be contributing to the patient's overall status.

    1. Ziegler DW, Agarwal NN. The morbidity and mortality of rib fractures. J. Trauma. 1994;37(6):975–9.
    2.  Bulger EM, Arneson M a, Mock CN, Jurkovich GJ. Rib fractures in the elderly. J. Trauma. 2000;48(6):1040–6
    3.  Flagel BT, Luchette F a, Reed RL, et al. Half-a-dozen ribs: the breakpoint for mortality. Surgery. 2005;138(4):717–23; discussion 723–5.
    4.  Battle CE, Hutchings H, Evans P. Risk factors that predict mortality in patients with blunt chest wall trauma: a systematic review and meta-analysis. Injury. 2012;43(1):8–17.
    5.  Callaway DW, Wolfe R.  Geriatric Trauma.  Emerg Med Clin N Am 25 (2007) 837–860
    6.  Harrington DT, Machan PB, Zacharias N. Factors associated with survival following blunt chest trauma in older patients: results from a large regional trauma cooperative.Arch Surg. 2010 May;145(5):432-7.
    7. Battle CE, Hutchings H, James K, Evans PA. The risk factors for the development of complications during the recovery phase following blunt chest wall trauma: a retrospective study. Injury. 2013;44(9):1171–6.
    8.  Eckstein M, Henderson S.  "Thoracic Trauma." Rosen's Emergency Medicine 7th ed. p. 387-388.
    9.  Brunett P, Yarris L, Cevik A.  "Pulmonary Trauma." Tintinalli's Emergency Medicine.  7th ed. p1756-1757.
    10 . Lee RB, Bass SM, Morris JA, MacKenzie EJ. Three or more rib fractures as an indicator for transfer to a Level I trauma center: a population-based study. J. Trauma. 1990;30(6):689–94.
    11.  Chauny J-M, Émond M, Plourde M, et al. Patients with rib fractures do not develop delayed pneumonia: a prospective, multicenter cohort study of minor thoracic injury. Ann. Emerg. Med. 2012;60(6):726–31. 

    Voodoo or EBM – Discharging the Asthmatic

    The Gist:  When discharging adult patients home from the Emergency Department (ED) following an acute asthma exacerbation, give a short burst of corticosteroids and an albuterol metered dose inhaler (MDI) with spacer [1].  Consider prescribing a short course of inhaled corticosteroids (ICS), although this is less strongly supported by the evidence [2-5].

    The "art of medicine" (i.e. voodoo) sneaks into the prescriptions given at discharge from the Emergency Department (ED) with acute asthma exacerbations.  Which oral steroid, what dose, and what duration?  What about an ICS?  Free Open Access Medical Education (FOAM) has educated me well on handling the asthmatic in extremis (ex: EMCrit, LITFL), but after generating and hearing questions about discharge medications from colleagues - I realized I should examine the rationale behind my practice.

    The Case:  A 21 year old female with a history of asthma never requiring intubation presents to the ED with gradually increasing shortness of breath over the past day.  She has a history of 2 days of preceding upper respiratory symptoms. The patient states she "used up" her remaining albuterol inhaler but continued to get worse. She states she moved to the area 2 months ago and her prescription for her daily inhaler ran out and she hasn't established a local physician.  EMS found the patient working to breath and administered albuterol via nebulizer with some relief.  In the department, she receives 15 mg nebulized albuterol, 6 puffs via MDI with spacer, and 60 mg of oral prednisone. Afterward, the patient has good air movement, is comfortably chatting with her visitor, has a sparse, occasional expiratory wheeze and would like to go home. What prescriptions should I write?

    Beta-agonist MDI + spacer
    Prescribing a beta-agonist inhaler at discharge is standard practice.  As a medical student, I wrote about this here, emphasizing the importance of the spacer and training. Ensure patients have a spacer and can adequately use an inhaler [1].

    Steroids to go. Steroids prevent relapses and hospitalizations [6,7].  Most practitioners and guidelines recommend a short burst of prednisone 40-60 mg for 5 days, although there is limited literature directly comparing dosage/duration of steroids in the dischargeable emergency department patient.
    • Little literature directly comparing doses.  Despite a 55-fold variation in steroid dosing, there's no added benefit from higher doses of steroids [6,7].
      • In medicine, it's becoming more apparent that more doesn't necessarily translate into better patient outcomes (ex: duration of antibiotics in uncomplicated UTI, steroids in croup) and this is likely the case with steroids in asthma.
    • Two dose dexamethasone (16mg)- a prospective RCT in adults (n=257) found that this regimen was non-inferior to a five day of prednisone (60 mg) with regard to asthma symptoms and relapse [8].  Note: This is probably an unnecessarily large dose of dexamethasone (60mg prednisone = 8 mg dexamethasone), but it appears that two doses of dexamethasone may be a good alternative to patients where compliance may be an issue - perhaps more in the future? More on this from EM Lit of Note
    ICS at discharge - Isn't this a primary care physician's (PCP) role?
    This is the most controversial point of discharging an asthmatic - many say it's not an EP's role to prescribe these medications, yet core emergency medicine texts recommend at least considering this at discharge and it's more common practice in other countries [3,7].

    In 2012, a Cochrane review covered the topic of ICS in addition to oral corticosteroids at discharge, including three RCTs with a total n=909 [4].
    • Asthma relapse at 7-10 days = OR 0.72 (95% CI 0.48-1.10) and 20-24 days OR 0.68 (95% CI 0.46-1.02).There were no statistically significant differences in the number of people experiencing an asthma relapse between patients treated with ICS and those on placebo (in addition to oral steroids).  There was a trend towards benefit.
    • Hospital admission was very low, at 2%, with no difference between groups so there's not sufficient power to determine a difference.
    • Asthma symptoms - subjective endpoint, difficult to quantify and extrapolate, and studies have yielded conflicting results.
    • One consideration with these studies is that patients were typically contacted for information at various intervals during the follow up period, serving as a reminder for compliance with various interventions (not quite real world).
    Non-evidence based thoughts on ICS:  
    • Access to PCP. While it's easy for us to write "follow up with your PCP within X days," this is less readily translated into reality. Patients may not have a local physician, there may be a paucity of appointment slots, or the patient may not have the time, means, or desire to follow through.  Furthermore, of those who do follow up with a PCP, many do not receive a prescription for an ICS as controller therapy according to a single center retrospective review [2].  
    • Cost-effectiveness.  Researchers at MUSC performed a cost-effectiveness analysis in pediatric patients presenting with asthma and found that routine ICS prescription at discharge showed cost-savings over recommending that a patient follow up with their PCP [9].  This model is limited in that it is merely a model and based on many assumptions, but is interesting.
    • The "teachable moment." ICS, in patients with asthma, prevent relapses and have thusly earned the role of "controller medication."  Experts who recommend ICS at discharge cite this as one reason 10].
    • Not all patients need ICS long-term, such as those patients with mild intermittent asthma. Many providers assert that as emergency providers, it's not our role to determine the long-term management of a patient's asthma.  Yet, patients visiting the emergency department with asthma exacerbations are cited as being the patients who typically benefit from ICS therapy. The side effects of ICS are minimal and local, especially considering a short term
      • Personally, I evaluate the individual patient, their access to care and compliance, their history and make a decision based on those components - knowing that a prescription for a beta-agonist MDI + spacer and a burst of systemic steroids will benefit the patient the most.  If a patient has been on an ICS in the past, I'm more likely to prescribe this at least a bridge until they see their PCP.
    Note bene:  Dr. Rowe is an author on many of these papers and has the following conflict of interest: received research support and speakers fees from GlaxoSmithKline (once: $1000) and AstraZeneca (multiple: ~$3000/year) in the past 3 years; he is not a paid consultant or employee of either.

    1. Cates CJ, Crilly JA, Rowe BH. Holding chambers (spacers) versus nebulisers for beta-agonist treatment of acute asthma (Review). Cochrane Database Syst Rev. 2006 Apr 19;(2):CD000052.
    2. Cydulka RK, Tamayo-Sarver JH, Wolf C, Herrick E, Gress S. Inadequate Follow-up Controller Medications Among Patients With Asthma Who Visit the Emergency Department. Ann. Emerg. Med. 2005;46(4):316–322.
    3. Cydulka R.  "Acute Asthma in Adults."  Tintinalli's Emergency Medicine. 7th ed. p 507-510.
    4. Edmonds ML, Milan SJ, Brenner BE, Camargo CA Jr, Rowe BH. Inhaled steroids for acute asthma following emergency department discharge.  Cochrane Database Syst Rev. 2012 Dec 12;12:CD002316 
    5. Waxman MA, Barrett TW, Schriger DL. A tale of two steroids: answers to the September 2011 journal club questions.  Ann Emerg Med. 2012 Feb;59(2):147-55. 
    6. Krishnan JA, Davis SQ, Naureckas ET, et al. An umbrella review: Corticosteroid therapy for adults with acute asthma.  Am J Med. 2009 November; 122(11): 977–991.
    7.  Rowe BH, Spooner CH, Ducharme FM, et al. Corticosteroids for preventing relapse following acute exacerbations of asthma.  Cochrane Database Syst Rev. 2007 Jul 18;(3):CD000195.  
    8. Kravitz J, Dominici P, Ufberg J, Fisher J, Giraldo P. Two days of dexamethasone versus 5 days of prednisone in the treatment of acute asthma: a randomized controlled trial.  Ann Emerg Med. 2011 Aug;58(2):200-4. 
    9.  Andrews AL, Teufel RJ , Basco WT , Simpson KN. A cost-effectiveness analysis of inhaled corticosteroid delivery for children with asthma in the emergency department. J Pediatr. 2012 Nov;161(5):903-7. 
    10.  Rowe RH, Bota GW, Clark S, et al. Comparison of Canadian versus American emergency department visits for acute asthma. Can Respir J. 2007 September; 14(6): 331–337.

    A System for the System – System Errors in the ED

    The Gist: In addition to cognitive biases, systems errors are ubiquitous in the emergency department (ED).  Free Open Access Medical education (FOAM) has inspired me to realize that one may mitigate some of these errors to improve patient care/outcomes by vigilance.

    As a fan of metacognition, I attempt to mitigate my cognitive errors through simple practices. A few months into residency, I occasionally find myself frustrated by systems-based errors.  Finally, something to blame other than myself!  As that attitude is not terribly productive, I've adopted steps to attempt to overcome these errors, something I foresee as an evolving and expanding process.

    Systems-based errors: reflect flaws or problems with process that are part and parcel of the health care delivery system.  These errors are often rooted in inefficiencies, issues with coordination of care, and communication [1].
      Case #1:  A 54 y/o male presented to Janus General with fever to 38.8C, malaise, and weakness over the past 2 days. BP 126/82, HR 90. Patient had a PICC line to the right arm that appeared clean, status-post left hip wash out for septic arthritis 3 weeks prior.  I ordered labs and fluid, with plans for antibiotics.  Despite repeatedly checking for the lab results, they didn't appear.  Eventually, I called the lab - who reported receiving the specimens just minutes earlier as the hospital's tube delivery system had malfunctioned.  This resulted in another blood draw from the patient for a repeat lactate (which turned out to be 6), as the specimen was too old, a delay in more aggressive care, and a silly/guilty feeling doctor.  Studies demonstrate that delays in antibiotic administration impact mortality, so while the patient didn't appear to be in the sickest group of patients this still could have resulted in a bad outcome [2].  But, it's the system's fault, right?

      Things I try to do to mitigate systems errors:
      Communicate with nursing and support staff.  Oftentimes, they can help get things done more expeditiously or identify barriers to the proposed treatment plan.

      Call the lab, radiology, pharmacy, etc.  Many steps exist between placing an order for a diagnostic evaluation or intervention and the completion of the order and an error can occur at any point. Furthermore, it's anecdotal, but I've been impressed with how face-to-face or verbal discussion of the "why" or need for urgency can expedite care.

      Establish a consistent method to reassess patients/labs.  Time can fly in the ED and often our attention is divided by unexpected sick patients.  For example, we can handle a mostly stable GI bleeder, a septic patient, and a chest pain patient.  However, the minute one begins to crash or a code rolls in, our attention becomes divided and non-critical patients may be placed on the back-burner.  As a trainee, it's easy to think that a stable patient will remain stable but this isn't always the case.  Furthermore, interruptions are rampant in the ED and this forced shift in attention may lead to delays in reassessment [3].
      • Some keep running list of things in their pocket/workstation that need follow up.  A unique solution offered by Dr. Jeremy Faust - use Siri [4].  "Siri, remind me to re-examine room 4 in 30 minutes." 
      Beware of alarm fatigue.  Alarms constantly ring in the ED and pop up in the EMR - but on occasion, they actually mean something.  It's important to catch it when it does.

      Approach sign out with caution.  This area of emergency medicine has garnered much attention as it may lead to a hotbed of cognitive errors and the nature of sign-out can vary within the institution. Most of the literature revolves around the inpatient experience, but I think that the vulnerability of this process translates into the ED [5]. Physicians and hospitals approach sign out differently, but there's a call for increased standardization [6].  Consider standardizing your own approach.
      • Re-examine the patient, their vital signs, and crucial diagnostic/interventional endeavors.  
      • Tip from Dr. Jeremy Faust - start sign-out saying something along the lines of: I'm intentionally going to be a bit annoying, don't take it personally.  Then, aggressively go through the case. Two heads are better than one. 
      Reexamine information received from outside physicians/transferring facilities.  Information often gets left out or lost in the series of communications surrounding transfers in care or partial work ups - minimize this by utilizing the patient's data.
      • Take a gander at a patient's EKG or diagnostics for yourself.  The "sinus bradycardia" for suspected accidental beta-blocker overdose may actually be a high degree AV block or a radiograph may be revealing.  
      Establish a consistent method of follow up.  A myth exists that emergency physicians do not or should not follow up their patients.  As a result of the discontinuity of care, we will not typically see our mistakes unless we look for them. Check out the EM Res podcast on this topic.
      • In the EMR, I keep a list, by month, of patients I see in the ED so I can easily check up on patients.  This takes 1 extra click per patient but saves time attempting to recollect the name and has created the expectation within myself that I will follow up on some of those patients.
      • Consider a "bounceback" program.  This provides larger buy-in, but provides an invaluable educational opportunity.  At my institution, if a patient returns within 7 days, we receive a notification.  Oftentimes these are unpreventable (the daily drunk patient) or an indication that we provided good discharge instructions; however, more often than not there's a pearl for the future.
      Use the EMR or family members to get to know the patient.  In the ED we don't know (most of) our patients, which can create fragmented care and an incomplete picture of our patient.  Valuable information can be found in the EMR (ex: the patient does, in fact, have baseline confusion and left sided weakness) or from family members who may be able to explicitly detail how the patient is different from baseline.

      Case #2 (months later): A 51 y/o female presented to Janus General with cough, tachypnea, decreased oral intake.  Temperature 37.6C, BP 106/78, HR 136. Physical exam significant for tachypnea, rhonci in bilateral lung fields, and dry mucosa.  I discussed the plan with the nurse, emphasizing the patient's need for fluids and aggressive care.  The patient had no access and prior unsuccessful attempts, so the nurse quickly identified the need for ultrasound guidance.  Siri reminded me to check on the antibiotics and reassess the vital signs while suturing another patient.  The patient's vital signs, lactate, and clinical appearance normalized in the ED after several liters of fluid and the patient went on to do well.

      Are there problems with attempted fixes for systems errors?
      • Improvements will fade as time passes secondary to decreased awareness, other foci of improvement, and lessened enthusiasm [1]
      • Fixes may produce opportunities for more errors
      1. Graber M, Gordon R, Franklin N. Reducing diagnostic errors in medicine: what’s the goal? Acad. Med. 2002;77(10):981–92. Available at:
      2.  Gaieski DF, Mikkelsen ME, Band RA,et al.  Impact of time to antibiotics on survival in patients with severe sepsis or septic shock in whom early goal-directed therapy was initiated in the emergency departmentCrit Care Med. 2010 Apr;38(4):1045-53.
      3. Elson, Ordell. Emergency Department Workplace Interruptions: Are Emergency Physicians “‘Interrupt-driven’” and “‘Multitasking’”? Academic Emergency Medicine 2000;7(11):1239–1243.
      4.  Faust, JS. "The 'Sultan of Signout'" ACEP News. August 2013. p 12-13.
      5. Arora V, Johnson J, Lovinger D et al. Communication failures in patient sign-out and suggestions for improvement: a critical incident analysisQual Saf Health Care. 2005 December; 14(6): 401–407.
      6.  Dhingra KR, Elms A, Hobgood C. Reducing error in the emergency department: a call for standardization of the sign-out process. Ann Emerg Med. 2010 Dec;56(6):637-42.

      Tools in the ED – Clinical Decision Instrument Basics

      The Gist:  Clinical decision instruments (CDIs) are all the rage in Emergency Medicine, especially for trainees still developing gestalt; however, these tools often require proper understanding and finesse for correct utilization.  FOAM (Free Open Access Medical education) sources such as Dr. Radecki's posts on NEXUSPECARN abdominal trauma, and the Ottawa SAH Rule as well as Dr. Spiegel's post on the Ottawa SAH Rule have helped hone the way I think about and utilize decision aids. This editorial in Annals of Emergency Medicine (podcast here) is a concise, excellent synopsis of questions to ask when evaluating CDIs.

      CDIs are tools, not rules.  These are typically derived through statistical methods in discrete populations. While the tools then undergo validation, these aids are artificial creations to assist providers in decision making and are not infallible. In the words of Mel Herbert regarding CDIs in Oct 2013's EMRAP : "you don't need to slavishly follow them."

      What does the decision tool add to the clinical context?
      • Is the CDI better than clinician gestalt in pursuing work-up or treatment of a disease process?
        • In the editorial, Green explains this well using the PECARN blunt abdominal tool.  Physician gestalt in ordering CTs for clinically significant abdominal injury: Sensitivity 99%, Specificity 56%.  The PECARN tool offered a sensitivity of 97% and specificity of 42% [1].  Thus, no real added benefit from the tool.
        • Numerous studies investigating pulmonary embolism (PE) have determined that strict application of tools perform no better than physician gestalt within the study populations [5]. 
      • Is the tool usable? Washington University's EM Journal club covered an example of issues with usability ACS CDIs.
      Clinical decision aids shouldn't replace gestalt.  
      • CDIs often appear to distill and codify components that comprise gestalt, which may be an enticing way to substitute clinical judgment.  As a medical student, I used these tools to aid in developing gestalt.  However, this could potentially be a bad habit in the making (see next point).
      • Many CDIs utilize gestalt as an entry criteria or as part of the actual aid.  
        • For example, in Tintinalli, Dr. Jeff Kline recommends applying PERC when the gestalt is there's a <15% chance that the patient has a PE, as this was the way in which the CDI was validated [3,4]. Thus, applying PERC to the wrong population may be deleterious.
      • Dr. Seth Trueger posted his PE diagnostic algorithm following an international Twitter debate on pathways and pre-test probability.  The gist of both of these is that a provider should consider the patient's clinical situation and downstream consequences or work up that may result. 

        What clinical question was the decision tool designed to answer?
        • Tools such as the Wells and Geneva scores were designed and validated as risk stratification tools, not rule-out or rule-in criteria.  
          • In this podcast, Dr. Scott Weingart offered some points of clarification on using CDIs to determine which patients to work up for PE.  He also harps on the point above - these scores are not designed to make the decision to work up/not work up a PE.
        • Measured outcome. Does the outcome reflect the clinical parameter you care about?
          • The Canadian Head CT aid seeks to identify head injuries that required neurosurgical intervention, not those that would resolve with no alteration in management.  One must decide whether this is the outcome both provider and patient care about.
        Is the patient part of the applicable population?
        • For example, it's important to note that the Canadian Head CT aid only applies to patients with: GCS 13-15, witnessed LOC, amnesia to the head injury event, or confusion and the authors excluded patients with "minor head injuries" that didn't have one of the aforementioned factors (see this post for more specific discussion of this example) [6].  Broadly applying the tool to patients who don't meet inclusion criteria or were excluded in the studied populations may lead to inappropriate stratification or intervention.
        • The performance of decision aids may depend on the prevalence of disease in the population. For example, PERC and Wells perform less well in high prevalence populations [5].
        • Various other factors such as developing vs developed setting, resources, etc may also alter the applicability of the decision aid in one's population. The more similar a paper's population is to your own, the more usable the decision aid.  For example, some decision aids may rely on a neurological exam performed by a neurologist versus an emergency physician.
        Has the decision aid been validated? If so, how?
        • Once a group derives a CDI, the tool must be validated to test it's rigor.  Dr. Newman gives a great explanation on this podcast (20 min mark). There are a few ways in which this typically happens:
          • Internal or external - validated in the same institution(s) or in other populations
          • Prospective or retrospective - data collected prospectively or retrospectively
          • Statistical or clinical - tool validated through statistical means or in "real life." The latter demonstrates usability and utility. 
          • Example: one can continue a data-collection study of parameters of the derivation portion of the study or one can use the tool in a population going forward to determine clinical utility. This is an example of the latter using the Canadian Head CT aid.
        Know whether a decision tool is a one-way or two-way instrument.  Misapplication of these tools may lead to excessive resource utilization and undermine the specificity of the aids.  [1]
        • One Way Decision Tools - Useful if all criteria are met.
          • Example: If someone is negative by PERC when utilized appropriately, it can indicate that the patient's risk of PE is below the test threshold. Conversely, one cannot say that if a patient is not PERC negative, then they necessitate work up for PE. 
        • Two Way Decision Tools - Can help a clinician decide both when to pursue an action and when not to pursue the action.  The "Ottawa ankle rule" is an example. [1]
        Note: I'm a mere novice with minimal statistics or EBM training, so these thoughts are more to be a reminder for myself than an in-depth analysis.

        1.  Green SM.  When do clinical decision rules improve patient care?  Ann Emerg Med. 2013 Aug;62(2):132-5. doi: 10.1016/j.annemergmed.2013.02.006. Epub 2013 Mar 30.
        3.  Kline, J.  Thromboembolism.  Tintinalli's Emergency Medicine.  7th ed.  p 434.
        4.  Kline, J. Prospective multicenter evaluation of the pulmonary embolism rule-out criteria. Thromb Haemost. 2008 May;6(5):772-80. doi: 10.1111/j.1538-7836.2008.02944.x. Epub 2008 Mar 3.
        5. Lucassen W, Geersing GJ, Erkens PM, et al. Clinical decision rules for excluding pulmonary embolism: a meta-analysis. Ann Intern Med. 2011 Oct 4;155(7):448-60. doi: 10.7326/0003-4819-155-7-201110040-00007.
        6.  Stiell IG, Lesiuk H, Wells GA, et al.  The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation). Ann Emerg Med. 2001 Aug;38(2):160-9.

        Blocked – ED Analgesia for Hip/Femur Fractures

        The Gist: Emergency physicians can safely provide regional analgesia under ultrasound guidance in patients with hip and femur fractures. Implementation of this analgesic modality has been slow in the US, probably secondary to knowledge translation issues, but momentum in practice and the literature base is growing. Check out this great Free Open Access Medical education (FOAM) podcast on femoral nerve blocks and nerve blocks in general. As a medical student and resident, I received training and performed these blocks with anesthesia in the peri-operative setting, an experience I highly recommend.

        The Case: An 81 year old female presented to Janus General's ED status-post fall with a shortened, externally rotated left leg. The patient complained of severe pain, pulse 105, BP 110/70.  X-rays showed a left intertrochanteric hip fracture, orthopedics consulted, and the patient received <0.1 mg/kg morphine.  The patient continued to report pain and was noted to be in atrial fibrillation, with a ventricular response of 130, and BP 96/60 on the monitor.  She was rate controlled with diltiazem, spontaneously converted her rhythm, remained uncomfortable throughout her ED stay, and received her surgery later in her hospital course.  A discussion over the potential for an ED placed nerve block initially failed (see section: "Why aren't we doing this more?') but after the patient's less than easy ED course, interest in this modality grew - could/should we do this in the ED?

        Why a nerve block?
        • Better pain control compared with standard care (opiates, typically) in both femur and hip fractures, with a hearty duration of analgesia [1-5].
          • In addition to many studies without a placebo group, a small ED RCT comparing placebo (saline) to ultrasound guided femoral nerve block in hip fracture patients, who also received standard care (morphine) demonstrated superior pain control [2]. 
        • Reduced consumption of opioids/additional analgesics [1-5].  
          • Note: While we can imagine ways in which this could result in clinically important benefits such as preserved mental status and respiratory and cardiovascular stability, this surrogate measure doesn't necessarily translate into a patient oriented outcome. 
        • Trends toward less delirium [1].  Both severe pain and pharmaceuticals can caused patients to be altered.  Limitations: most studies excluded patients with dementia or other cognitive impairments and this mostly stems from the in-patient literature.
        • It's safe, especially under ultrasound guidance [1-5,7-9].
        • It's easy and physicians typically feel comfortable after brief training sessions  [7, 11].
        Type of regional anesthesia - Two main types exist for these indication, the femoral nerve block (FNB) and the fascia iliaca compartment block (FICB), sometimes called a "modified FNB," as it deposits anesthetic in a similar region [8].  Detailed instructions: Ultrasound podcastNeuroaxiom website. Note: a good neurovascular exam should always precede a nerve block.
        • FICB (video) - targets the nerves of the lumbar plexus (L2-L4) and provides more proximal coverage than the femoral nerve block with a larger volume (typically bupivacaine diluted with saline).  Operator places needle more laterally than in the FNB, thereby reducing risk of intravascular infiltration/damage (use of ultrasound for both techniques weakens this point).  Landmark technique can be performed safely without ultrasound, if needed [5,7]. Probably covers the hip better than the FNB.
        • FNB - sometimes called a "3-in-1 block", as the goal is to target the femoral, lateral femoral cutaneous, and obturator nerves.  Routinely used for femur fractures in the pediatric population. 
        • Definitive literature on which block performs best is lacking, especially since most relied upon landmark techniques or nerve stimulators rather than ultrasound guidance.  Some anesthesiologists scoff at the notion of FNB for hip fracture and find the FICB more reasonable; however, there's literature to support FNB in acute hip fracture management as well [2,3].  
          • Likourezos et al from Maimonides Medical Center just finished a study of hip fracture patients randomized to FICB, FNB, or intravenous morphine. Results are pending but may help elucidate this distinction. 
        Are people actually doing this?
        • Yes.  Much medical practice is location dependent, owing to the interests, training, and flux of individuals/thought and this is no different.  Dr. Al Sacchetti described the integration into his practice in the EMRAP Feb 2012 episode, and EPMonthly featured an article as well.  Here are some thoughts from the UK and commentary from Australia:  

        • It's not just a bunch of procedure hungry members of the FOAM community pushing a sexy procedures, core texts such as Tintinalli recommend considering FNB in hip fracture [6].  Papers report that since 2004 in some Denmark hospitals, ED placed FICB are routinely administered in hip fracture patients prior to x-ray in Denmark [7].
        Why aren't we doing this more
        • Lack of knowledge.  While many people have been doing this for years and uptake appears to be greater outside of the US, some are unaware that this modality is easily and commonly performed by emergency physicians.  
          • A survey of emergency physicians in 3 Canadian teaching hospitals demonstrates that while the majority acknowledged the benefit of the nerve blocks in hip fractures, the majority did not perform them [10].  This argues against the assertion that lack of knowledge is key and is more likely a knowledge translation issue.
        • Time.  It's initially quicker to order morphine on the computer than 10-15 minutes at the patient's bedside but we may fail to consider the potential consequences of analgesics/sedation in vulnerable populations.  However, re-dosing of opioids is common, especially as patient's may be in the ED for several hours and complications of these interventions may also end up resulting in more time demand on the EP.  
          • Note: Time estimate based on my experience as a trainee in the OR setting (which included consent and components not typically performed in ED FNB/FICB blocks: full sterile drape/procedure, and catheter placement). Studies have demonstrated feasibility in the ED setting [2-5,7].
        • Consultants.  Confrontation with orthopedics is a commonly cited excuse for not providing regional anesthesia in the ED, yet often this is cited without talking with ortho about a particular patient's case.  Instead of initiating dialogue, it's often assumed that the orthopedist will decline.

        • Although, safely performed around the world for decades, it's relatively new in US EDs and therefore hasn't become routine like many other places.  Intravenous analgesia has been a mainstay of many ED pain complaints for years and has become routinized and we may skip over thinking - "What is best for this patient?" An increasing number of emergency departments have protocols to place blocks prior to x-rays in patients over 50 with hip/femur fractures.  The US emergency department literature on this analgesic modality is growing quickly, but much of it stems from the 21st century and many EPs have not received formal training [10].  There's a balance between being an early adopter and waiting to be pushed to adopt a practice.  
        • Ultrasound is an integral part of EM residency training in the US and is creeping into medical school curriculum.  Utilization of ultrasound may be daunting for some who have become accustomed to a particular practice pattern. 
        • Duration of analgesia - this is part of the benefit of the nerve block.
        • Interference with motor movement - Some argue that a patient may be more prone to falls but this is in the in-patient/operative literature and has not resulted in any increase in mortality or morbidity [1].  This has not been demonstrated in any of the ED literature, and is amenable to fall protocol/precaution [2-5, 7].
        • Concerns about ay also mask a developing compartment syndrome.  Case reports exist of compartment syndrome in the setting of a nerve block, but these are post-operative and the breadth of the literature doesn't support this as a concern in most patients [8].
        • Like any procedure, there are risks such as infection, bleeding, nerve damage, etc; however, these are exceedingly rare and a risk-benefit evaluation is necessary [1-5, 7-9].
        1. Abou-Setta AM, Beaupre LA, Jones CA, et al. Pain Management Interventions for Hip Fracture. Comparative Effectiveness Review No. 30. AHRQ Publication No. 11-EHC022-EF. May 2011.
        2. Beaudoin FL, Haran JP, Liebmann O. A comparison of ultrasound-guided three-in-one femoral nerve block versus parenteral opioids alone for analgesia in emergency department patients with hip fractures: a randomized controlled trial. Acad Emerg Med. 2013;20(6):584–91.
        3. Beaudoin FL, Nagdev A, Merchant RC, et al. Ultrasound-guided femoral nerve blocks in elderly patients with hip fractures. Am J Emerg Med. 2010;28(1):76–81. 
        4. Haines L, Dickman E, Ayvazyan S, et al. Ultrasound-guided fascia iliaca compartment block for hip fractures in the emergency department. J Emerg Med. 2012;43(4):692–7. 
        5. Godoy Monzon D, Iserson K V, Vazquez J a. Single fascia iliaca compartment block for post-hip fracture pain relief. J Emerg Med.  2007;32(3):257–62. 
        6. Steele MT.  Tintinalli's Emergency Medicine.  7th ed.  p 1856.
        7. 1. Høgh A, Dremstrup L, Jensen SS, et al. Fascia iliaca compartment block performed by junior registrars as a supplement to pre-operative analgesia for patients with hip fracture. Strategies in trauma and limb reconstruction (Online). 2008;3(2):65–70.
        8. Karagiannis G, Hardern R. Best evidence topic report. No evidence found that a femoral nerve block in cases of femoral shaft fractures can delay the diagnosis of compartment syndrome of the thighEmerg Med J. 2005 Nov;22(11):814.
        9. Wedel DJ, Horlocker TT. Miller's Anesthesia. 7th ed. pp. 1652-1655.
        10.Haslam L, Lansdown A, Lee J, et al. Survey of Current Practices: Peripheral Nerve Block Utilization by ED Physicians for Treatment of Pain in the Hip Fracture Patient Population. Canadian geriatrics journal : CGJ. 2013;16(1):16–21.

        Kappa – It’s Greek to Me

        The Gist:  Many junior physicians use clinical decision instruments as an objective means of risk stratification or clinical decision making; however, these have subjective components.  Kappa, a measure of interrater agreement, is a commonly expressed statistic in medical literature, particularly in clinical decision aids.  Understanding the use, strengths, and weaknesses of kappa may help with application of decision aids and appraisal of literature.

        The Case: A 13 year old boy presented to the Janus General ED after being struck in the head with a baseball bat.  He had a slight headache, no vomiting, normal mental status, and unremarkable physical exam except a hematoma over his left parietal region.
        • I presented the case as low-risk by PECARN with ~<0.05% chance of a clinically significant injury.  An attending inquired as to how I determined that the mechanism was "not severe."  Would my assessment change if Mark McGuire swung the bat that hit my patient?  Similarly, where was my threshold with the 18 month old that fell off a bed? Did the precise number of feet matter? The truth was, probably not, not because it wasn't listed in the objective criteria of the decision aid, but because after my assessment of the patient, I already estimated that the likelihood of a clinically significant injury was minimal. I wondered:  How did they come up with these variables (was there really a difference between falls from 3 ft and 4 ft)? How frequently would other people disagree with my seemingly "objective" determinations?
        I found a paper by Nigrovic et al the next day that evaluated the agreement between nurses and physicians in the application of PECARN to mild blunt head injury pediatric patients.  This study demonstrates the differential level of agreement, or reliability, between elements of the PECARN predictors - with notable differences between subjective and objective components.*  For example, everyone agreed on vomiting, but anything containing the word "severe" was a little more nebulous.
        • History of vomiting - 97% agreement between nursing and physician assessment, with an outstanding kappa of 0.89 (95% CI 0.85-0.93). 
        • Severe injury mechanism - 76% agreed, kappa 0.24 (95% CI 0.13-0.35) in the age<2 cohort and kappa = 0.37 (95% CI 0.29-0.45) in the age 2-18 group.
        Wait, what is this kappa (k) business?
        • It quantifies interrater reliability - a measure of the degree of agreement between observers that is greater than chance alone.
          • Sometimes, even in medicine, clinicians and trainees guess.  For example, when reading a radiograph and deciding on atelectasis versus infiltrate, a physician may hedge and choose one.  This may seem straightforward, but imagine a variable such as severity of headache.  Suppose one clinician has a terrific headache and rates headaches encountered that day as non- or less severe.  The cases when that clinician and another agree would therefore be based on chance.  
        • Calculation: (Observed Agreement - Agreement Expected by Chance)/(1-Agreement Expected by Chance) - Ok, so, the actual calculation is more complicated and is explained here.
        • Assesses precision/reliability
          • Using the aforementioned study, one can see that nurses and physicians reliably detected the presence of vomiting but less reliably agreed on the presence of a severe mechanism of injury or severe headache.
        What does the value mean?
        • -1.0 = perfect disagreement, +1.0 = perfect agreement

        What are the limitations of kappa?
        • The expected agreement is affected by abnormal prevalence.  In a skewed sample, the observed agreement may be markedly different than the relative agreement (1).  This is referred to as the kappa paradox, and there are various ways to compensate for this issue.
          • Rare findings - agreement between observers may not be as reliable and will be reflected by a lower kappa.  Looking at the Nigrovic et al paper, the kappa for palpable skull fracture is abysmal at 0.00, yet the proportion of physicians and nurses in agreement was 98%.  This exists as a product of the rarity of the finding, as 1/434 and 7/434 physician and nursing assessments were positive, respectively.  Similarly, signs of basilar skull fracture was fair at 0.37 with an enormous confidence interval (95% CI 0.07-0.67).  
        • Generalizability. Diversity of skill/experience may affect kappa.
          • Are the raters emergency physicians? medical students? specialized radiologists?
          • This was ostensibly what Nigrovic et al sought to determine - do clinicians at various levels of expertise agree?  The answer - it depends.  
        What now? As a junior trainee, the ways I evaluate patients and objective data is different than that of a senior clinician.   Thus, I'm armed with this knowledge to acknowledge the limitations of the clinical decision instruments I use, understand why and how the variables are not hard and fast "rules," and use both to better patient care.
          *Note: The developers of PECARN (original study) only selected criteria with a minimum kappa of 0.5 (with a lower bound of the confidence interval of 0.40).

          1.  de Vet HC, Mokkink LB, Terwee CB, Hoekstra OS, Knol DL.  Clinicians are right not to like Cohen’s κ 2013;346:f2125
          2.  Nigrovic LE, Schonfeld D, Dayan PS, Fitz BM, Mitchell SR, Kuppermann N. Nurse and Physician Agreement in the Assessment of Minor Blunt Head Trauma. Pediatrics. 2013. Available at: Accessed August 29, 2013.