EM Quick Hits 11 Blunt Cerebrovascular Injury, Physostigmine, TEE in Cardiac Arrest, Understanding Nystagmus, Subtle Inferior MI, Choicebo

Topics in this EM Quick Hits podcast

Emily Austin on physostigmine for anticholinergic toxidrome (1:02)

Walter Himmel on understanding nystagmus to differentiate central vs peripheral causes of vertigo (07:00)

Rob Devins on the role of transesophageal echocardiogram in cardiac arrest (18:43)

Jesse MacLaren on nuances in inferior MI ECG changes and aVL (25:06)

Andrew Petrosoniak on a practical approach to blunt cerebrovascular injury (29:43)

Reuben Strayer on choicebo (38:46)



Podcast production, editing and sound design by Anton Helman

Podcast content, written summary & blog post by Andrew Petrosoniak, Emily Austin, Sucheta Sinha and Anton Helman

Cite this podcast as: Helman, A. Petrosoniak, A. Austin, E. Devin, R. Himmel, W. Strayer, R. EM Quick Hits 11 - Blunt Cerebrovascular Injury, Physostigmine, TEE in Cardiac Arrest, Understanding Nystagmus, Subtle Inferior MI, Choicebo. Emergency Medicine Cases. December, 2019. https://emergencymedicinecases.com/em-quick-hits-december-2019/. Accessed [date].

The return of physostigmine for antimuscarinic poisoning delirium



* Recall anticholinergic/antimuscarinic poisoning toxidrome: "mad as a hatter, blind as a bat, red as a beet, dry as a bone, hot as hell, full as a flask" - hyperthermic, hypertensive, tachycardic, dry axilla (compared to sympathomimetic patients who will often be diaphoretic), agitated, delirious, urinary retention, pupillary dilation.

* Benzodiazepines are often used to control agitation, but they are sedating and will not resolve the delirium associated with the antimuscarinic toxidrome.

* Physostigmine, the antidote for the antimuscarinic toxidrome reverses both agitation and delirium.

* Physostigmine has suffered from a bad reputation after being incorrectly used in TCA overdose with QRS prolongation, leading to cardiac arrest in case reports.

* It is safe and effective in anticholinergic overdose associated with delirium as long as the ECG shows a normal QRS and QTc.

* Physostigmine dose is 1-2 mg IV over 10 minutes for adults and 0.02 mg/kg for children. It may need to be re-dosed if symptoms return.



Expand to view reference list



* Arens AM, Shah K, Al-abri S, Olson KR, Kearney T. Safety and effectiveness of physostigmine: a 10-year retrospective review. Clin Toxicol (Phila). 2018;56(2):101-107.

* Burns MJ, Linden CH, Graudins A, Brown RM, Fletcher KE. A comparison of physostigmine and benzodiazepines for the treatment of anticholinergic poisoning. Ann Emerg Med. 2000;35(4):374-81.





Understanding nystagmus to differentiate central vs peripheral causes of vertigo



* Differentiating the various types of nystagmus can help differentiate central vs peripheral causes of vertigo.

* Two main types of nystagmus: pendular nystagmus (eyes move repetitively in a sinusoidal pattern) and jerk nystagmus (eyes move slowly in one direction and rapidly correct in the opposite direction).

* Types of jerk nystagmus that are always central: pure vertical, pure rotational, and multidirectional nystagmus (where the fast component changes direction depending on which direction the patient is looking).

* Types of jerk nystagmus that are almost always peripheral: unidirectional horizontal nystagmus ...