Podcast 1027: Oculocardiac Reflex

Contributor: Taylor Lynch, MD

Educational Pearls:

What is the oculocardiac reflex?

• The oculocardiac reflex occurs when pressure or traction is put onto the globe of the eye or extraocular muscles that causes increased stimulus to the ophthalmic division of the trigeminal nerve (Cranial Nerve V).

• The trigeminal nerve then has a reflex arc with the vagus nerve (Cranial Nerve X) causing it to be stimulated and create downstream outward parasympathetic effects.

• The activated vagus nerve will cause an inhibitory signal to be sent to the heart, causing bradycardia.

• This bradycardia can also be present as certain arrhythmias like AV blocks.

What are the patient presentations and treatment considerations for the oculocardiac reflex?

• In the emergency department or pre-hospital field it can present in patients with frank orbital trauma with otherwise unexplained bradycardia including: blow-out fractures, retrobulbar hematoma, foreign bodies in the eye, or be caused from eye-dressings placed too tightly.

• For treatment, the most important step is recognizing the condition and removing the offending agent that may be causing the reflex, and seeking to reduce pressure.

• It is also important to have the patient on cardiac monitoring.

• If that is not effective, atropine can be considered at 0.5mg repeat doses to improve the bradycardia, but ultimately trying to end the reflex arc is important.

References

1. Chua AW, Chua MJ, Leung H, Kam PC. Anaesthetic considerations for strabismus surgery in children and adults. Anaesth Intensive Care. 2020;48(4):277-288. doi:10.1177/0310057X20937710

2. Arnold RW. The Oculocardiac Reflex: A Review. Clin Ophthalmol. 2021;15:2693-2725. doi:10.2147/OPTH.S317447

Summarized by Dan Orbidan, OMS3 | Edited by Dan Orbidan & Ahmed Abdel-Hafiz, NREMT-P

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