Vagal Reflex-Induced Asystole during Suspension Laryngoscopy: A Rare Complication.

Suspension laryngoscopy is commonly used in diagnostic and operative procedures involving the larynx. This study presents a rare case of asystole during suspension laryngoscopy. A 58-year-old woman with an unremarkable medical history underwent suspension laryngoscopy for a left polypoid vocal cord under general anesthesia. Anesthesia induction and tracheal intubation were performed without complications. However, upon inserting a direct laryngoscope and exposing the larynx, her heart rate gradually decreased and asystole occurred. The direct laryngoscope was immediately removed, and atropine sulfate was injected. Spontaneous circulation was restored after 20 s of asystole. The direct laryngoscope was then re-inserted, and the operation was successfully completed without complications. Asystole was attributed to stimulation of the pharyngolaryngeal mucosa through direct laryngoscope-induced vagal reflex. This case highlights the need for surgeons and anesthesiologists to be aware of this rare but potentially life-threatening complication and emphasizes the importance of vigilant electrocardiography monitoring during direct laryngoscope adjustment.