Intraoperative cardiac arrest etiologies in head and neck surgery: A comprehensive review

BackgroundThe etiologies of intraoperative cardiac arrest within otolaryngology are not well understood as they are rare events. MethodsA comprehensive review of the etiologies and corresponding pathophysiologic neural mechanisms of intraoperative cardiac arrest in otolaryngologic surgery are examined. ResultsThe occurrence of this rare complication has been described in a range of head and neck procedures, including but not limited to suspension laryngoscopy and oncologic resections in the neck, maxilla and thyroid. Three anatomically distinct pathways leading to intraoperative cardiac arrest are described: direct vagal stimulation, the trigeminocardiac reflex and the baroreceptor reflex. All three share the final common pathway of parasympathetic signaling to the sinoatrial node via the cardiac fibers of the vagus nerve. ConclusionWith a firm understanding of the mechanistic underpinning of this rare phenomenon, otolaryngologic surgeons can be better prepared for its occurrence.