R&R In The FASTLANE 126

Welcome to the 126th 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 6 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

Dubosh NM, et al. Sensitivity of Early Brain Computed Tomography to Exclude Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis. Stroke. 2016  PMID: 26797666.

• 5 Trials with 8907 patients with normal neurological examination with thunderclap headache and head CT within 6 hours. 13 missed aneurysmal SAH. In patients presenting with thunderclap headache and normal neurological examination, normal brain CT within 6 hours of headache is extremely sensitive in ruling out aneurysmal SAH, but not 100% sensitive.
• This is systematic review and meta-analysis including more than 8000 patients in studies aiming to rule-out SAH with a head CT within 6h of headache onset; the two major studies are included (Perry and Blok). After pooling the data, adjusting for biases and considering incidence of SAH, the ability to rule-out SAH for a CT obtained within 6h is excellent. If conditions are appropriate the missing rate is less than 1/1000. 
• A review and meta-analysis looking at the literature in an attempt to more definitively answer the question of whether a LP is indicated in the evaluation for possible SAH after a negative CT within 6 hours. The authors determine there to be a potential miss rate of ~1-2/1000 patients. An important number to communicate when discussing risks/benefits with patients.
• Of significance, this “number needed to tap” comes with some need to know caveats:
  • neurologically intact patients
  • thunderclap headache presentation
  • clear time of onset and modern CT within 6 hours
  • CT reading by attending radiologist experienced in neuroradiology
• Recommended by: Salim R. Rezaie, Daniel Cabrera, Jeremy Fried
• Further reading: Is 6 hour CT for SAH debate over? (EM Literature of Note)

Motov S et al. Intravenous Subdissociative-Dose Ketamine Versus Morphine for Analgesia in the Emergency Department: A Randomized Controlled Trial. Ann Emerg Med 2015. PMID: 25817884

• Although many emergency providers are using ketamine for acute pain management, there is little high quality literature exploring its use and relative efficacy to traditional interventions. This article is a well done, RDCT comparing non-dissociative dose intravenous ketamine (0.3 mg/kg) to intravenous morphine (0.1 mg/kg). The authors found no statistically significant difference between the two at 30 minutes. This data gives further credence to the use of ketamine for acute pain relief in the ED though it does not demonstrate superiority.
• Recommended by Anand Swaminathan

Disla E, et al. Costochondritis. A prospective analysis in an emergency department setting. Arch Intern Med. 1994 PMID: 7979843

• Brilliant classic paper on “costochondritis,” or rather, the lack thereof. 122 consecutive chest pain patients were evaluated by the Rheum faculty; of those who Rheum diagnosed with costo, 6% ruled in for MI! (oddly, so did 28% of the control group. but this was the early 1990s so who knows). Hat tip to Judd Hollander who references this paper and quotes: “There is no use for the term costochondritis.”
• Recommended by Seth Trueger

Carlson JN, Wang HE. Does Intubation Improve Outcomes Over Supraglottic Airways in Adult Out-of-Hospital Cardiac Arrest? Ann Emerg Med 2015. PMID: 26475247

• This Systematic Review Snapshot summarizes the findings of an important article examining the ROSC and neurologically intact survival differences between supraglottic airways (SGA) and endotracheal intubations (ETI) in out of hospital arrest patients. While there is clearly limited evidence of poor quality, what the authors were able to demonstrate is that there is a weak relationship between ETI and neurologically intact survival with an OR 1.33 (1.04–1.69). All studies looked at to determine this relationship were observational in nature and of low quality of evidence. Importantly, the authors remind us of the ongoing trials which will help determine the answer to this important clinical question.
• Recommended by Jeremy Fried

Asha SE, Miers JW. A Systematic Review and Meta-analysis of D-dimer as a Rule-out Test for Suspected Acute Aortic Dissection. Ann Emerg Med. 2015 PMID: 25805111

• Would be nice if ddimer was useful to exclude aortic dissection, and this meta-analysis shows that it is… in patients who are so low risk they probably shouldn’t be worked up for dissection in the first place (no PMH risk factors; no concerning HPI features; and no exam findings; but who have no other cause for symptoms and wide mediastinum or unexplained hypotension). Most useful? Patient who got dimer appropriately to rule out PE, admitted for chest pain, and admitting team asks “what about dissection?”
• Recommended by: Seth Trueger

Kim S, et al. Searching for answers to clinical questions using google versus evidence-based summary resources: a randomized controlled crossover study. Academic medicine : journal of the Association of American Medical Colleges. 2014. PMID: 24871247

• Rushing around the emergency department, it is obviously a lot more tempting to just google something rather than find a specific medical resource, but how good is Google? This is a prospective, randomized, controlled, crossover study in which they took 48 internal medicine residents and asked them to answer a series of medical questions. They were randomized to answer 5 questions, either use Google, or to use their choice ot DynaMed, First Consult, or Essential Evidence Plus. They then ‘crossed over’ and answered another 5 questions using the opposite tool. This was repeat for 48 weeks. There was no difference in time to correct answer, response rate, or accuracy. They answered found answers for 80% of the questions, but the correct answer in only 60%. Bottom line: Google doesn’t look worse than these specific medical tools, but I really want my residents to be right more than 60% of the time in an open book test. Maybe neither is any good?
• Recommended by Justin Morgenstern
• Further reading: Can Google answer clinical questions? (Canadiem)