Quarterly Literature Update – September 2017

Do abscesses need antibiotics after incision & drainage (I&D)
Two recent studies have rendered many with the conclusion that antibiotics improve cure and recurrence rates when added to I&D.  Talan et al randomized people with abscesses after I&D to TMP-SMX or placebo and found improved clinical cure rates in the TMP-SMX group (80.5% vs 73.6%). This year, Daum et al randomized patients to TMP-SMX, clindamycin, or placebo after I&D and specifically looked at small abscesses (<5 cm) and again found higher rates of 10-day clinical cure in patients receiving antibiotics (TMP-SMX 83.1%, Clindamycin 81.7%, Placebo 68.9%). Many people have pushed the idea that all abscesses need antibiotics after drainage based on these studies. However, these studies included patients with significant surrounding cellulitis (on average, >25 cm2) and most recommendations have historically recommended antibiotics to those with more than a 5 cm diameter of surrounding cellulitis
  • Bottom Line: After I&D of an abscess, give antibiotics if there is >5 cm diameter of surrounding cellulitis (~30 cm2 total).  We probably do not need to do this if less cellulitis.
  • Stats/Study Design point: With any study check out the baseline/demographics table and ask - are these patients like my patients.
FAST is fast, but is it good?
The FAST exam, initially developed to assess for free fluid in unstable trauma patients, is widely used and may be an area where indication creep (i.e. we start expanding the indication for it) has really taken hold. Holmes et al performed an RCT on 945 stable pediatric blunt trauma patients who were randomized to standard trauma evaluation + FAST or just a standard trauma evaluation. There was no difference in rates of CT scans (~50% in each arm), missed intra-abdominal injuries (n=1 in FAST arm), or hospital charges. Even things like length of stay and hospitalization rates were about the same between groups.
  • Bottom Line: Keep FASTing trauma patients who are unstable or borderline unstable and management may change based on the FAST results (i.e. thoracotomy or OR). Find a negative FAST on a trauma patient? That’s called a false sense of security.
  • Stats/Study Design point: Beware of indication creep (using a test in patients it was not originally designed or validated in - this can change parameters such as sensitivity and specificity)

A magic sepsis cocktail?
Marik et al have made a wave in public media for a magic sepsis cocktail of vitamin C, hydrocortisone, and thiamine. In this paper, they published their findings of a paltry 47 patients who underwent treatment and report an incredible mortality reduction in the cocktail arm (8.5 % 4/47 vs 40.4% 19/47). The primary author, very well respected in the sepsis/critical care community, has argued that this treatment should be adopted immediately because prior studies show biological plausibility. However, this is a supremely tiny hypothesis generating study subject to incredible bias (see this podcast) due to no blinding and other factors. Further, prior studies of individual components (ex: steroids) have been negative.
  • Bottom Line: Vitamin C, hydrocortisone, thiamine is an inexpensive and relatively benign therapy; however, a single retrospective study of 47 patients cannot inform us of efficacy or harm.  Medicine is rife with examples of adopting therapies too early because they look promising based on terrible studies only to later find out that they don’t work. Further studies will be needed to determine whether or not this practice should be adopted.
  • Stats/Study Design pearl: Before/after studies are subject to significant bias and confounding. In this study we worry about the lack of blinding as all providers and patients knew what they were getting and that there was this new "life saving" cocktail - perhaps this could have influenced other care.

Haloperidol HUGS and Love
Gastroparesis and cyclic vomiting patients are frustrating and often their medication allergy lists are extensive. Enter haloperidol, a butyrophenone antipsychotic (dopamine antagonist), a sister medication of droperidol. Roldan et al randomized 15 patients with gastroparesis to 5 mg IV haloperidol + conventional treatment and 18 patients to conventional treatment alone. Pain and nausea dropped from 8.5/10 to 1.83 (pain) and 4.53/10 to 1.83 (nausea) at 1 hour in the haloperidol group compared with a drop from 8.28 to 7.17 (pain) and 4.11 to 3.39 (nausea) in the placebo group. Another small, not especially well done observational study, termed HUGS, by Ramirez et al echo these findings.
  • Bottom Line:  These studies aren't necessarily practice changing but correlate with significant prior literature for pain and nausea treatment in migraines and in the anesthesia literature.It’s worth a shot to try haloperidol 2.5-5 mg IV in patients with gastroparesis (or even cyclic vomiting/cannabinoid hyperemesis although this is based on case series). It's nice to have literature out there saying "hey, this is a thing we are doing."
  • Stats/Study Design Pearl: Size does matter when it comes to the methods section. In a retrospective study you should be able to replicate the study by reading the methods. The Ramirez study had a paltry 11 sentences.

PERC - Love it but ignore it?
It’s well accepted that in a patient with low pretest probability (15% or less, i.e. Low Risk by Wells Criteria), we can rule out pulmonary embolism (PE) using the PERC criteria. The miss rate using this approach is <2%, which is the cut point where further workup and treatment would cause more harm than good (test-treatment threshold). Apparently, we suck at actually following this evidence based approach according to a prospective observational study by Buchanan et al of patients with chest pain and/or shortness of breath looked at PE testing rates in PERC negative patients. Over 25% of patients who were PERC negative underwent further PE testing and 7.2% went straight to CTPA or V/Q, skipping the d-dimer.
  • Bottom Line: If you think of working up PE, consider the patient’s risk of PE, then think of PERC, and then d-dimer before you jump to CTPA. In low-risk patients (ex: meets Wells Low Criteria) with possible PE that are PERC negative, do not do further testing to assess for PE.
  • Stats/Study Design Pearl: The test-treatment threshold is important. This is the idea that there is a point at which the harms of further workup and treatment of a disease process equal or become greater than harm of not pursuing the test. For PE this has been established at about 1.8%.

The End of Apneic Oxygenation?
Placing a nasal cannula at 15 LPM (or more) during RSI has become pretty standard practice in many ED rapid sequence intubations (RSI), often deemed apneic oxygenation (ApOx). The ENDAO trial randomized 206 ED patients undergoing RSI who had at least 3 minutes of preoxygenation to ApOx or no ApOx. Nobody was blinded. The study was looking for a difference in lowest mean oxygen saturation before groups, which they did not find (92% vs 93%).
  • Bottom Line: This study, and others like it, are negative, probably because the desaturations we are looking to prevent with ApOx are rare. ApOx may be helpful in difficult intubations or those with poor physiologic parameters who are likely to desaturate, unfortunately, we sometimes don’t know who these people are.
  • Stats/Study Design Pearl: Choice of primary outcome is important. It may seem like a difference in oxygen saturation is clinically important but when oxygen saturations are globally high, this is not going to make a difference to the patient.

    Steroids for all that wheezes?
    Many patients with lower respiratory tract infections (LRTI), particularly with wheezing, receive empiric steroids, inhaled beta-agonists, and possibly antibiotics (such as azithromycin), yet the evidence behind this is scare in patients without underlying lung disease (asthma/COPD). Hay et al randomized 401 patients presenting to outpatient clinics with cough and signs of LRTI who had no history of asthma or COPD to either 40 mg prednisolone daily for 5 days or placebo. They found no difference in duration of moderately bad or worse cough (~5 days in each group) or severity of symptoms on days 2-4. Of note, about 40% of the patients in this study were wheezy.
    • Bottom Line: Just because a patient with a cough wheezes, it doesn’t mean they will benefit from steroids. Keep giving steroids to patients with flares of asthma and COPD but we can be much more selective in the those without these lung diseases.

    Bonus Throwback(Cutting Edge from 2010) - Stop the pulse checks in codes
    We are terrible at pulse checks - they are inaccurate and insensitive. The pulse check during a code (i.e. after the initial <10 sec pulse check by a healthcare provider to establish arrest) is nowhere in ACLS. Nada. The 2010 AHA Guidelines state: "Because of difficulties with pulse assessments, interruptions in chest compressions for a pulse check should be minimized during the resuscitation, even to determine if ROSC has occurred." The ACLS guidelines recommend pulse checks during CPR only if an organized rhythm is seen
    • Bottom Line: Continue to assess for rhythm changes during CPR - this can take place in 2-3 seconds. There’s no need to stop for a pulse check but you may if you see ETCO2 rise significantly (just be aware it’s not very accurate). You can take a few second ultrasound clip during a rhythm check to assess for cardiac contractility.

    Bonus Non-Clinical Paper - Boys > Girls?

    There’s been a lot of talk about the gender pay gap, but surely it doesn’t apply to academic emergency medicine, right? Wrong. Masden et al used 2015 survey data from full-time faculty academic emergency physicians and found that women made > $19,000 less than men. You may say that doesn’t account for rank, fellowship status, administrative roles, location, clinical hours, etc. But again, that would be incorrect. That gap was after adjusting for all of these potential confounders.
    • Bottom Line: Women make less than men in academic emergency medicine. Transparency and awareness may help so share the paper with your colleagues and chairs and don’t be afraid to negotiate.

    An ED Model for Shared Decision Making

    The Gist: Shared decision making (SDM) is increasingly common in the ED, yet most people, particularly trainees, are untrained in this area. A proposed framework in an Annals of Emergency Medicine article by Probst et al proposes a framework to guide clinicians (or train them) in the implementation of SDM in the busy ED and combats common misconceptions regarding SDM.
    1. Ask yourself: is this clinical scenario appropriate for SDM - is there clinical uncertainty or equipoise, is the patient capable of engaging in SDM, and is there time?
    2. Have the conversation - Acknowledge that a decision needs to be made and share information about the risks and benefits of each option. Explore the patient's values and circumstances to help come to a decision.
    The Case:  The nurses give you a heads up the next patient to be seen is in a lot of pain.  You see a 25-year-old healthy male who is doing the “kidney stone dance” – pacing around the room while holding an emesis basin. He's had left flank pain for the past two hours, nausea, but has a reassuring abdominal exam with minimal tenderness.  His urinalysis shows red cells in the urine and he's feeling better after analgesia.  What's next - CT scan? Ultrasound? Discharge with neither?

    An SDM in the Emergency Department Framework from the Probst et al Annals article

    1.  Is this scenario appropriate for SDM? 
    • Is there more than one reasonable option at this time?
    The current literature regarding renal colic in the ED supports multiple options as the next reasonable

    step [1-5]. Non-contrast CT scan is the historic option; yet, recent evidence supports ultrasound as a reasonable next step, and an ultrasound-first diagnostic plan might decrease radiation exposure for this young patient [2]. Experts have also argued that renal colic can be diagnosed clinically, and imaging is not necessary in classic cases with low probability of dangerous alternative diagnoses [1]. The trade-offs between these options might be important to this patient; if he’s feeling better or concerned about lifetime radiation risk, he may not want to wait for a CT scan, and conversely, if he’s about to set off hiking the Appalachian Trail, he may want to know the location and size of his stone.  
    Obviously, there are clinical reasons why some cases of suspected renal colic warrant CT scans – fever, concern for an alternate diagnosis, or solitary kidney [6].
    • Is the patient able to make his own medical decisions? 
    While this patient may know little about the trade-offs involved in the clinical question, research has
    shown that patients do want to be told about the risks of radiation prior to CT scans [7]. This patient isn't altered or otherwise incapacitated - he can participate in decision making.
    • Do you have time? Does your patient have time?
    The latter question is easy to answer: unless he’s eloped because he’s feeling better, your patient
    clearly has time to have this conversation. Whether you have time depends on the severity of other patients’ conditions and your ability to explain the trade-offs in a manner that he can understand. The more you practice this skill, the better you will be at it, and it’s worth noting that the results of your conversation may speed up his discharge, creating space for another patient and increasing throughput.

    2.  Have the conversation (if the answers to the above questions are yes)
    • Acknowledge that a decision needs to be made - 
    “I suspect that you have a kidney stone – kidney stones cause severe pain, vomiting, and blood in the urine, all of which you had. At this point, we have to decide if it makes sense to do some more imaging.”
    • Share Information in Regard to Management Options and the Potential Harms, Benefits, and Outcomes of Each - 
    “For some people, we do a CT scan – the benefit of a CT is that we know exactly how big the stone is, which helps us know if you’re going to need a procedure from a urologist to get it out. Most people with kidney stones pass the stone by themselves, and the CT isn’t helpful. The downside of a CT is that it takes time and it exposes you to radiation – and we know that every time you get exposed to radiation it increases your future risk of cancer ever so slightly. Also, if your pain comes back and doesn’t go away, it might make more sense to get a CT later – and we wouldn’t want to have to do two CT scans. Most people who have one kidney stone will have another one in the next 10 years – so you could end up with multiple CT scans over your lifetime. The other option is an ultrasound: it gives us some information and sometimes we get a CT scan if we see a lot of swelling in your kidney, but it doesn't show us how big the stone. Because I can do the ultrasound right now, people often go home sooner when they have an ultrasound, if they don’t need a CT. If we decide on the ultrasound, it’s important that you have a doctor you can follow-up with if you are feeling worse.”
    • Explore Patient Values, Preferences, and Circumstances - Probing the patient about what's important to them is key - they may not disclose difficulties with transportation, their activities of daily living, or their travel plans.
    “How are you feeling? Do you have a doctor you can see in the next week or so? Would you be able to get back to the ED if you had a problem? Kidney stones usually pass in a week or two – do you have any travel planned?”
    • Decide Together on the Best Option for the Patient, Given His or Her Values, Preferences, and Circumstances
    If a patient has a preference, this part is easy – maybe they’re in a hurry, worried about the cost of a CT, or have had multiple CT scans, or maybe they have an upcoming trip and want certainty.
    Many patients won't have a preference, and they may ask you for advice. Share your opinion but recognize that there is a huge power differential.

    “If I had a kidney stone, and the pain medication worked, I wouldn’t be in a rush to get a CT scan – but might get one in a week or two if I still had alot of pain. If I had some reason that I felt like I needed more information right now, like I was going on a cruise, then I might get the scan.”

    Presenting both sides in the explanation of your opinion empowers the patient to choose either the
    option you endorsed or the other option without feeling like they are disagreeing with the expert.

    1. Wang RC. Managing Urolithiasis. Annals of Emergency Medicine 2016;67(4):449–54.
    2. Smith-Bindman R, Aubin C, Bailitz J, et al. Ultrasonography versus Computed Tomography for Suspected Nephrolithiasis. N Engl J Med 2014;371(12):1100–10.
    3. Brisbane W, Bailey MR, Sorensen MD. An overview of kidney stone imaging techniques. Nat Rev Urol 2016;:1–9.
    4. Fiore M. A proposal algorithm for patients presenting to the Emergency Department with renal colic. Eur J Emerg Med 2016;23(6):456–8.
    5. Xiang H, Chan M, Brown V, Huo YR, Chan L, Ridley L. Systematic review and meta-analysis of the diagnostic accuracy of low-dose computed tomography of the kidneys, ureters and bladder for urolithiasis. J Med Imaging Radiat Oncol 2017;:1–9.
    6. Türk C, Petřík A, Sarica K, et al. EAU Guidelines on Diagnosis and Conservative Management of Urolithiasis. European Urology 2015;:1–7.
    7. Robey TE, Edwards K, Murphy MK. Barriers to computed tomography radiation risk communication in the emergency department: a qualitative analysis of patient and physician perspectives. Acad Emerg Med 2014;21(2):122–9.

    Slaying Prehistoric Practice – Killing off the Routine Pulse Check

    The Gist: It's time to kill off the routine pulse check every two minutes. While some providers and systems have moved away from routine pulse checks, perfunctory cessation in compression to identify pulses happens as 'the norm' across the United States. Check the rhythm as indicated - without halting compressions if you have a monitor that is able to sense despite compressions or if there is a spike in end tidal capnography (etCO2) or another compelling reason such as gain on arterial line tracing, or during a brief, <10 second pause, if compressions interfere with rhythm analysis [1].

    Most of us recognize that, to the best of our knowledge, interruptions in chest compression may be deleterious to return of spontaneous circulation and, theoretically, neurologic outcome [2]. We may even devise complicated ways of reducing time without compressions including mechanical compressions and hands-on defibrillation. These interventions are not evidence based and the yield is minimal. A more simple fix exists - stop checking for pulses routinely.  This isn't some novel wild idea.

    The American Heart Association guidelines do not recommend any specific interval for pulse check after the first initial pulse check for healthcare providers [3].  Beginning in 2010,  however, the AHA guidelines begin discouraging routine pulse checks:
    "Because of difficulties with pulse assessments, interruptions in chest compressions for a pulse check should be minimized during the resuscitation, even to determine if ROSC has occurred" [4].

    It's really difficult to identify pulselessness in < 10 seconds
    . Few people can determine the presence of pulselessness in 10 seconds. Dick et al performed a study of patients placed on cardiopulmonary bypass, and providers were blinded to the presence of pulsatile flow. Only two percent of experienced providers (n=209) were able to determine that a patient was pulseless in under 10 seconds [5].
    Enforcement of time between compressions may be mitigated by having someone count down from 10 during the rhythm analysis. We often have the individual performing chest compressions do this and they are trained and reminded at the beginning of the resuscitation to resume compressions when they reach zero.

    Pulse checks are inaccurate. A study by Tibaballs et al again had providers assess for a pulse in patients on bypass with and without pulsatile flow. They found 78% accuracy in identification of the presence or absence of a pulse [6]. While an accuracy of 78% may seem high, this means that approximately one in four times we are wrong. This means we may feel the reverberation of our own pulse and the truly pulseless patient may have an unnecessary and perhaps deleterious delay in chest compressions. Cardiac ultrasound and arterial line tracings demonstrate contractility and flow with superior diagnostic characteristics, although each has their limitations [7].

    Why would we undertake a diagnostic strategy if we know it it is inaccurate and insensitive? Changing practice is difficult. In critical situations we default to what is familiar, what we know.  It is time to move away from the pulse check. We may still need to check for rhythm analysis at periodic intervals, and this is supported by the AHA guidelines. Some monitoring systems allow for this concurrently with compressions (filter out the baseline), while others do not. Many of us are also compelled to search for reversible causes of arrest with ultrasound, many of which do not require an interruption in compressions.

    If you're curious about why we are so stubborn to let go of our practices, check out this post on unlearning practices we adore.

    1. Soar J et al. "European Resuscitation Council Guidelines for Resuscitation 2015: Section 3. Adult advanced life support." Resuscitation, October 2015, Pages 100 - 1472.
    2. Eftestøl T, Sunde K, Steen PA.  Effects of Interrupting Precordial Compressions on the Calculated Probability of Defibrillation Success During Out-of-Hospital Cardiac Arrest. Circulation.2002; 105: 2270-2273.
    3. Link MS, Berkow LC, Kudenchuk PJ et al. Part 7: Adult Advanced Cardiovascular Life Support. Circulation. 132(18 suppl 2):S444-S464. 2015
    4.Berg RA, Hemphill R, Abella BS et al. Part 5: Adult Basic Life Support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 122(18_suppl_3):S685-S705. 2010.
    5. Dick WF, Eberle B, Wisser G, Schneider T. The carotid pulse check revisited: what if there is no pulse? Crit Care Med. 2000 Nov;28(11 Suppl):N183-
    6. Tibballs J, Weeranatna C. The influence of time on the accuracy of healthcare personnel to diagnose paediatric cardiac arrest by pulse palpation. Resuscitation. 81(6):671-5. 2010.
    7. Gaspari R et al. Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest. Resuscitation 2016 Sep 27