Asystole due to stimulation of the supraorbital nerve: abrupt and potentially fatal presentation of the trigeminocardiac reflex.

We present a case of sudden asystole that was elicited via the trigeminocardiac reflex in a patient undergoing surgery for a frontal sinus fracture. Asystole occurred after mild stimulation of the supraorbital nerve during dissection along the superior orbital rim. Anticholinergics were administered and lidocaine-soaked gauze was applied to the exposed wound. The patient was an athlete and had pre-existing sinus bradycardia. We hypothesise that the severe reflex response was associated with his underlying increased vagal tone. When performing surgery in patients with increased vagal tone, preventative measures to diminish the trigeminocardiac reflex are recommended. Further studies are needed. © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.