Sudden asystole without any alerting signs during cerebellopontine angle surgery

Abstract

The trigeminocardiac reflex (TCR) is manifested by the sudden development of cardiac dysrhythmia, bradycardia, arterial hypotension, apnea, and gastric hypermotility that occurs especially during ocular and craniofacial surgery and tumor resection at the cerebellopontine angle (CPA). A 58-year-old man who presented with headache, hearing loss, and vertigo was admitted to the hospital. A cerebral magnetic resonance imaging revealed a tumor with a diameter of 4 × 3 cm at the right CPA. His medical history was unremarkable. All preoperative tests were normal. The patient was premedicated with midazolam at the operating room. Anesthesia was induced with intravenous propofol, fentanyl, lidocaine, and vecuronium, and maintained with sevoflurane in 50% air and oxygen. Monitors consisted of electrocardiogram, pulse oximetry, radial artery catheter, central venous pressure catheter (CVC), capnograph, precordial doppler, neuromuscular stimulator, and urinary catheter. After the patient was placed in the sitting position, his hemodynamic variables and arterial blood gas analysis were normal. During tumor dissection under the trigeminal nerve, a sudden asystole developed with a loss of sinus rhythm on the electrocardiogram, invasive blood pressure wave, and the doppler sound. The surgical team was informed, and manipulation was halted. The surgical area was irrigated with saline, inspiratory oxygen flow was increased to 100%, and the patient's position was changed to lower the head to heart level and to left lateral decubitus. No air bubbles aspirated from the CVC. Atropine (3 mg, intravenous) bolus was administered. When no cardiac rhythm was seen within 60 seconds, a precordial thump was applied, and thoracal compression was started. A return of normal sinus rhythm was observed within 20 seconds. The surgical procedure was resumed. Recovery period from anesthesia was uneventful.