I took another month off, but the blog and accompanying podcast are back with what I think is an interesting collection of articles… Continue reading “Articles of the month (May 2017)”
A monthly collection of the most interesting emergency medical literature I have encountered
Each month my inner nerd comes out, and I bore my group with an e-mail containing the most interesting EM papers I have read in those 30 days. I figured I would start sharing those summaries here as well, starting at the beginning of 2015. These are obviously very brief, informal summaries. I always suggest reading the paper for yourself. Now to catch up, starting with January 2015…
Beta-blockers might be useful in refractory V.Fib.
Driver BE et al. 2014. Use of esmolol after failure of standardcardiopulmonary resuscitation to treat patients with refractory ventricular fibrillation. Resus 85(10):1337-41. PMID: 25033747
Not a definitive paper (it was retrospective) but raises a treatment that I have never used, or seen used, but have heard talked about a lot recently. In patients with refractory V.fib/ electrical storm, we don’t usually reach for anti-hypertensives, but beta blockers might be a good idea. Use of esmolol in these patients was associated with more ROSC and more neurologically in-tact survival.
Bottom line: Esmolol 500mcg/kg bolus over 1 min then start at 50mcg/kg/min.
Patients with a listed penicillin allergy get more C.Diff, MRSA, VRE
Macy E, Contreras R. 2014. Health care use and serious infection prevalence associated with penicillin “allergy” in hospitalized patients: A cohort study. J Allergy Clin Immunol. 133(3):790-6. PMID: 24188976
This was a large retrospective cohort study of 51,000 patients in California. Patients with a listed penicillin allergy received more clinda, vanco, and quinolones. They also had 23% more C.Diff, 14% more MRSA, and 30% more VRE (relative numbers) as compared to their matched, non penicillin allergic patients.
Bottom line: It might be worth digging more into those penicillin allergies.
Tranexamic acid topically stops epistaxis
Zahed R et al. 2013. A new and rapid method for epistaxis treatment using injectable form of tranexamic acid topically: a randomized controlled trial. Am J Emerg Med. 31(9):1389-92. PMID: 23911102
A good sized RCT (216 patients) compared usual packing to 500mg (5ml) of TXA on a cotton ball in the anterior nose. This worked quickly (bleeding was stopped at 10 min in 70% of the TXA group compared to only 30% of ant pack group) and lasted (no significant difference in 24 hour rebleed rate between groups, but only 5% in TXA versus 10% in ant pack group had rebleeds). Patients preferred the TXA to packing (what a surprise). Biggest problem with the paper: unable to blind (and I am pretty sure that less than 70% of my anterior packings are still bleeding at 10 minutes.)
Bottom line: Worth trying, as I wouldn’t want to go home with an anterior pack (but my personal experience with this isn’t nearly as positive)
Let’s stay on topic: CRASH 2: TXA reduces mortality in trauma
Effects of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage (CRASH-2): a randomised placebo-controlled trial. Lancet 2010; 376: 23-32. PMID: 20554319
I didn’t actually read this this month, but it is a landmark paper, so why not review. I was originally skeptical, but we probably should be doing this until we know better. Summary: Huge RCT (over 20,000 patients) of adult trauma patients the doc thought was at risk of significant bleeding, got 1 gram of TXA over 10min and then another over 8 hours. They showed an absolute decrease in mortality of 1.5% or an NNT of 68. Why was I skeptical – the majority of these patients were in a very rural setting, without access to trauma surgeons (some sites did not even have a fax machine for the randomization procedure) so this may not apply in Canada, and TXA was supposed to work by decreasing bleeding, but it didn’t. However – I am starting this think this might apply to us. We don’t have a trauma surgeon and a lot of time might pass during transfer, so maybe we are more like rural Africa than I originally thought. I would caution however – they conclude that there were no side effects from TXA. However, when looking for side effects the setting might really matter. If a patient in rural Africa gets a DVT or a PE, how easy do you think it is to get the test to prove it? Therefore, this study could easily have missed blood clots in patients sent back to their villages.
Bottom line: Probably all trauma patients sick enough to transfer should get TXA 1 gram IV.
Anti-emetics don’t work in adults?
Egerton-Warburton et al. 2014. Antiemetic Use for Nausea and Vomiting in Adult Emergency Department Patients: Randomized Controlled Trial Comparing Ondansetron, Metoclopramide, and Placebo. Annals of Emergency Medicine 64(5): 526-32. PMID: 24818542
This was a prospective, double blind, RCT of 270 patients from Australia comparing zofran versus maxeran versus placebo. And you guessed it, much like everything we do: our treatments don’t work. Or, more accurately, placebo and both the drugs decreased nausea scores by about 2.5 out of 10. More side effects with maxeran. Two problems: 1) Dose – zofran only 4mg, but we often given more; maxeran – they gave 20mg – which might explain the side effects. 2) They only measured outcomes at 30 minutes – maybe anti-emetics help at 2 or 3 hours? However, it was a good RCT and treatment was no better than placebo.
Bottom line: Maybe we slightly overuse these medications?
AEDs may have some major problems
Calle PA et al. 2015. Inaccurate treatment decisions of automated external defibrillators used by emergency medical services personnel: Incidence, cause and impact on outcome.Resuscitation (Ahead of print) PMID: 25556589
This one worries me, but I am not sure what to do about it. For 135 consecutive patients (837 total cardiac rhythms) these authors retrospectively looked at the rhythm strip and compared it to what the AED actually did. Out of 148 rhythms that should have been shocked, the AED missed 23 (16%) mostly due to artifact or fine v.fib. It also shocked when it should not have, although with no obvious harm, 4% of the time. (I can’t remember the model of the AED – maybe some are better or worse?)
Bottom line: AEDs might miss shock-able rhythms 16% of the time!!!
Apneic oxygenation decreases desaturations during intubation
Wimalasena Y et al. 2014. Desaturation rates during rapid sequence intubation by an Australian helicopter emergency service. Annals of Emergency Medicine. (Online ahead of print) PMID: 25536868
This was one of the papers I spoke about at grand rounds. Not high quality, being a retrospective before and after study. Essentially, this pre-hospital/ retrieval helicopter EMS service in Australia added the use of a nasal canula to their protocol for all intubations. Historically, 22.6% of patients had some desat. With nasal oxygen 16.5% had some desat.
Bottom Line: Essentially no cost, and a NNT of 16 to prevent a desat. Blow some Os up their nose.
Mortality decreases when all the best cardiologists are out of the country
Jena AB et al. 2014. Mortality and Treatment Patterns Among Patients Hospitalized With Acute Cardiovascular Conditions During Dates of National Cardiology Meetings. JAMA Intern Med. PMID: 25531231
This article is relatively useless from a science standpoint – but I love the relatively absurd conclusions. It is a retrospective chart review where they looked at the cardiac outcomes for patients admitted during national cardiology meetings (and therefore when all the “top” cardiologists and cardiac surgeons were away). Many fewer procedures were done and MORTALITY WENT DOWN.
Bottom line: Have your heart attack when the leading cardiologists are all out of town.
A better aproach to PEA
Littmann L et al. 2014. A simplified and structured teaching tool for the evaluation and management of pulseless electrical activity. Medical Principles and Practice. 23:1-6. PMID: 23949188 Free full text: http://www.karger.com/Article/Pdf/354195
The standard epinephrine and push treatment is actually associated with worse outcomes in PEA. To that end, most guidelines say that in PEA the essential action is to determine the underlying cause. But the Hs and Ts are hard to remember during a code, and also don’t tell you which cause is the most likely. This new algorithm does through 3 simple steps: 1) QRS wide or narrow? 2) Ultrasound to find cause (Or use clinical judgement) 3) Empiric treatment based on the first 2. This is not one where my summary will suffice – its a 4 page paper and its free. I strongly suggest taking 20 minutes and reading it through. (Or, you can read the First10EM blog post: The simplified approach to PEA)
Bottom line: There is a better way to approach PEA
Cheesy Joke of the Month
A man awoke in the recovery room after a bad car accident. He screamed for his doctor: “Doctor, doctor, I can’t feel my legs!!”
The doctor replied: “I know you can’t – I’ve cut off your arms.”