R&R In The FASTLANE 171

Welcome to the 171st edition of Research and Reviews in the Fastlane. R&R in the Fastlane is a free resource that harnesses the power of social media to allow some of the best and brightest emergency medicine and critical care clinicians from all over the world tell us what they think is worth reading from the published literature.

This edition contains 5 recommended reads. The R&R Editorial Team includes Jeremy Fried, Nudrat Rashid, Soren Rudolph, Anand Swaminathan and, of course, Chris Nickson. Find more R&R in the Fastlane reviews in the : Overview; Archives and Contributors

This Edition’s R&R Hall of Famer

Hinson et al. Risk of Acute Kidney Injury After Intravenous Contrast Media Administration. Ann Emerg Med 2017. PMID: 28131489.

• This was a single center retrospective cohort study where they assessed patients who underwent contrast enhanced CT, unenhanced CT, or no CT for acute kidney injury. 17,934 ED visits were examined and logistic regression modeling with and without propensity scoring matching were used to assess for an association of IV contrast utilization and kidney injury. In short, no such association was found. While limited by the single center retrospective nature of the study, this is the largest and best study we have on the topic. Importantly, patients with a Cr > 4.0 were excluded. The authors, I believe, appropriately sum up their conclusions that: “Our data also suggest that in cases in which contrast-enhanced CT is indicated to avoid delayed or missed diagnosis, the potential morbidity and mortality resulting from a failure to diagnose possibly life-threatening conditions outweigh any potential risk of contrast-induced
  nephropathy in patients with serum creatinine levels up to 4.0 mg/dL.”
• Recommended by: Jeremy Fried

Kawano T, et al. Epinephrine use in older patients with anaphylaxis: Clinical outcomes and cardiovascular complications. Resuscitation 2017. PMID: 28069483

• This is a retrospective chart review that looked at 492 adults meeting criteria for anaphylaxis at one of two emergency departments over a 5 year period. They looked to see how often older patients were treated with epinephrine and if there were complications. Older was defined as over 50 years old – sorry if that offends you. These older patients were less likely to get epinephrine (36% vs 60%), but for some reason the older population was much more likely to be given an excessive dose of epinephrine (more than 0.5 mg IM or 100 mcg IV; 16% vs 1%). Either way, those are really low rates of epinephrine use for anaphylaxis, and I agree with the definition of anaphylaxis that they used. There were 3 “cardiac complications” in patients who received IV epinephrine, all of whom received an excessive dose (300 mcg IV push). None of these were real complications: 1 asymptomatic and completely resolving ST depression, 1 self resolving 3 minute run of stable ventricular tachycardia with no further events, and 1 run of atrial fibrillation so short they couldn’t catch it on an ECG, followed by some transient ST depression and a negative stress test. There were 2 cardiac complications in the IM epi group, both at normal doses, and both in the elderly. Again, they don’t sound too bad. One was transient 3/10 chest pain and ST depression that resolved without therapy and didn’t require intervention. Another patient developed ST depression with sinus tachycardia and did have a slight troponin elevation, but that was followed by a completely normal cardiac catheterization. With retrospective data, we have to remember that there might have been a reason that epi was withheld in so many of the older patients.Bottom line: This data reinforces that epinephrine is safe to give and should be given in all age groups in the presence of anaphylaxis, but please know the dose of IV epi
• Recommended by: Justin Morgenstern

Özturan IU, et al. Comparison of loop and primary incision & drainage techniques in adult patients with cutaneous abscess: A preliminary, randomized clinical trial. Am J Emerg Med In press. DOI: http://dx.doi.org/10.1016/j.ajem.2017.01.036

• Some people already treat some abscesses with the loop-drainage technique instead of a traditional I&D, yet spotty evidence exists for this practice. This small pilot study of 46 patients randomized patients with abscesses approximately 3 cm long with 7 cm diameter of surrounding cellulitis to traditional I&D (with irrigation, no packing) or loop drainage technique (with irrigation. Neither group received antibiotics. The preliminary results show loop drainage performs about the same as I&D with regard to complications and satisfaction. Larger studies may be able to tease out any clinically important differences between treatments, as this study wasn’t powered to do this.
• Recommended by: Lauren Westafer

Upchurch CP et al. Comparison of etomidate and ketamine for induction during rapid sequence intubation of adult trauma patients. Ann Emerg Med 2017. PMID: 27993308

• We all love ketamine but is it superior to etomidate for RSI in trauma? This study’s methodology doesn’t allow it to put this question to rest but it gives us some insight into the question. The authors performed a retrospective before-and-after study (first 2 years, etomidate was routinely used. second 2 years, department protocol shifted to encourage ketamine over etomidate) and found no statistically significant difference in mortality: OR 1.41 (CI: 0.93 – 2.16). However, the 3% difference in mortality favoring etomidate may be important if it held up in a larger trial powered to look for this difference. Bottom line, we don’t know if one agent is superior to another and for now we’ll continue to act on incomplete information.
• Recommended by: Anand Swaminathan

Righini M et al. Anticoagulant Therapy for Symptomatic Calf Deep Vein Thrombosis (CACTUS): A Randomised, Double-Blind, Placebo-Controlled Trial. Lancet Haemotol 2016. PMID: 27836513

• This is an underpowered study, that gives us very little guidance on how to treat distal calf DVTs. As there is no clear optimal approach at this time, I would advocate for a shared decision making strategy regarding the use of anticoagulation vs no anticoagulation in isolated low-risk, distal DVTs. With either strategy, close follow up with repeat ultrasound, over the next few days, should be performed to assist with further management and treatment decisions.
• Recommended by: Salim R. Rezaie
• Further reading: The CACTUS Trial: Anticoagulation for symptomatic calf deep vein thrombosis (R.E.B.E.L. EM)