EM Quick Hits 56 – Nitroglycerin in SCAPE, REBOA, Diverticulitis Imaging, CRAO, Penicillin Allergy, Physician Personality

Topics in this EM Quick Hits podcast

Justin Morgenstern on the use of high dose nitroglycerin in SCAPE (1:08)

Andrew Neill and Leah Flanagan on Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) indications and evidence (8:33)

Brit Long on indications for CT in suspected diverticulitis (26:41)

Tahara Bhate on Central Retinal Artery Occlusion (CRAO) and diagnostic error (34:47)

Matthew McArthur on penicillin allergy and penicillin challenges (42:58)

Susan Lu on how ED physician personality influences patient outcomes (52:16)

Podcast production, editing and sound design by Anton Helman

Written summary & blog post by Shaila Gunn, Brit Long, Matthew McArthur, edited by Anton Helman

Cite this podcast as: Helman, A. Morgenstern, J. Neill, A. Long, B. Bhate, T. McArthur, M. Lu, S.  EM Quick Hits 56 - Nitroglycerin in SCAPE, REBOA, Diverticulitis, Diagnostic Error, Penicillin Allergy, Physician Personality. Emergency Medicine Cases. April, 2024. https://emergencymedicinecases.com/em-quick-hits-april-2024/. Accessed May 30, 2024.

High dose nitroglycerin for SCAPE - the first RCT

High-dose versus low-dose intravenous nitroglycerine for sympathetic crashing acute pulmonary edema: a randomised controlled trial by Siddiqua et al. 2024, the first RCT on this topic, suggests higher doses of nitroglycerin that are typically used are safe and effective.

P: 52 SCAPE patients with hypoxia, hypertension, respiratory distress; all were also receiving BiPAP

I: High dose nitroglycerin group; IV bolus nitroglycerin 600-1000 mcg followed by an infusion starting at 100 mcg/min

C: Usual dose nitroglycerin; no bolus; nitroglycerin infusion starting at 20-40 mcg/min, max 250 mcg/minute

O: Resolution of symptoms in 6 hours was 65% for the high dose group vs 12% in the usual dose group (NNT = 2); endotracheal intubation was 4% in the high dose group vs 19% in the usual dose group; the high dose group also had lower admission rate, shorter length of stay, fewer MACE; there was no hypotension in either group; the usual dose group reported more headaches compared to high dose group

Is this all too good to be true?

* Limitations: This was a small, single center, unblinded trial; even though these outcomes are largely objective, this does not mean they are not biased (i.e. only recording expected results); the results may also not be generalizable as the patients in this study were very sick

However, other literature would agree.

* Wilson et al. 2016: 2 mg (2000mcg) push doses were associated with decreased ICU admissions and only 2% having hypotension

* Matthew et al. 2021: high dose IV bolus of nitroglycerin 600-1000 mcg had no complications

* Houseman et al. 2023: Nitroglycerin infusions starting at >100 mcg/hr had a only a 4% rate of hypotension

Practical bottom line => Consider a nitroglycerin bolus dose 2-3 sprays SL (800-1200 mcg) OR IV bolus 500-1000 mcg if an IV is in place. Then start a nitroglycerin infusion at 100 mcg/min and titrate. Remember than BiPAP is another critical intervention for all of these patients.

More on Sympathetic Crashing Acute Pulmonary Edema (SCAPE)

<a aria-expanded="false" aria-controls="0b33fa2dd9db0f86e" role="button" data-toggle="collapse" data-parent="#accordion-29418-4" dat...