EM Quick Hits 24 Lateral Canthotomy, Cannabis Poisoning, Hyperthermia, Malignant Otitis Externa, BBB in Occlusion MI, Prone CPR

Topics in this EM Quick Hits podcast

Anand Swaminathan on lateral canthotomy (0:54)

Emily Austin on pediatric cannabis poisoning  (7:38)

Reuben Strayer on an approach to hyperthermia  (13:22)

Brit Long on diagnosis and management of malignant otitis externa  (20:28)

Jesse McLaren on ECG diagnosis of occlusion MI in patients with BBB (25:42)

Peter Brindley on prone CPR (32:15)



Podcast production, editing and sound design by Anton Helman. Voice Editing by Raymond Cho.

Podcast content, written summary & blog post by Anton Helman, Emily Austin, Brit Long and Reuben Strayer

Cite this podcast as: Helman, A. Swaminathan, A. Austin, E. Strayer, R. Long, B, McLaren, J. Brindley, P. EM Quick Hits 24 - Lateral Canthotomy, Cannabis Poisoning, Hyperthermia, Malignant Otitis Externa, BBB in Occlusion MI, Prone CPR. Emergency Medicine Cases. December, 2020. https://emergencymedicinecases.com/em-quick-hits-december-2020/. Accessed [date].

Lateral canthotomy - cantholysis



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Time is eye; a lateral canthotomy is indicated for trauma patients with orbital compartment syndrome within 60-120 minutes of onset of ischemic features (decreased visual acuity and RAPD) as a temporizing measure to definitive surgical evacuation of the retrobulbar hematoma.



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Clinical clues to orbital compartment syndrome include mechanical consequences (proptosis from the retrobulbar hematoma - most easily seen from the head of the bed with the patient lying supine - IOP>40mmHg and impaired extraocular movements), and ischemic consequences (decreased visual acuity, RAPD and a blown pupil)



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Do not wait for a CT to confirm a retrobulbar hematoma; the clinical diagnosis is all you need to go ahead with the procedure



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Gear: 2% Lidocaine with Epinephrine, 25g needle, straight clamp, iris scissors, toothed forceps



* The lateral canthotomy procedure

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* Ensure adequate sedation and local anesthesia

* Crush and clamp the lateral canthus for 1-2 minutes with the straight clamp

* Make a 1-1.5cm cut to the lateral canthus with the iris scissors while an assistant is pulling the lower lid out of the way with toothed forceps

* Palpate the lateral canthal ligament (because the surgical field is usually very bloody, finding the lateral canthus ligament becomes a tactile procedure and has been likened to the feel of a guitar string) and cut the inferior branch of the lateral canthal ligament

* Recheck the IOP; if still elevated cut the superior  branch of the lateral canthal ligament







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Medical treatment for OCS is similar to that of acute angle closure glaucoma with mannitol, acetazolamide, pilocarpine and timolol.





Traumatic retrobulbar hemorrhage: Emergent decompression by lateral canthotomy and cantholysis paper



https://www.youtube.com/watch?v=tgQaKVGynFA

Expand to view reference list



* Vassallo, S., Hartstein, M., Howard, D., & Stetz, J. (2002). Traumatic retrobulbar hemorrhage: Emergent decompres...