Intraoperative Bradycardia: Evaluating Vasovagal Events in Adult Suspension Microlaryngeal Surgery.

Abstract

To measure the incidence and severity of bradycardia during suspension microlaryngoscopy (SML), identify risk factors predictive of vasovagal responses (VVR) during SML, and propose immediate interventions. This study retrospectively assessed intraoperative vital signs in all patients who underwent SML with a single surgeon between September 2023 and June 2025. A VVR was defined as a drop in HR of ≥ 10 beats per minute (bpm) resulting in a nadir of < 60 bpm within a five-minute period. Patient demographics, medical history, anesthetic medications administered, and intraoperative vital signs were recorded. Chi-squared tests and Fisher's Exact tests compared patients with and without VVR during suspension. Significant bradycardia occurred in 17/190 (8.9%) of patients undergoing SML. No significant differences were identified based on demographics, comorbidities, intubation VVR, laryngoscope size, or perioperative medications. The pulse dropped an average of 16 bpm in symptomatic patients. On average, it took patients 9 min to recover. The laryngoscope was removed in all 17 cases; 8/17 recovered without further intervention, and 9/17 received IV glycopyrrolate reactively. No patients developed asystole. VVR occurred in 8.9% of patients undergoing SML, often with significant bradycardia and the need for glycopyrrolate intervention. Otolaryngologists performing SML should be aware of patients' heart rate during SML and be prepared to treat acute changes immediately. Data presented can serve as foundational research for future, prospective investigations into this phenomenon.