Trigemino-cardiac reflex—The trigeminal depressor responses during skull base surgery

Objective To observe and analyze the occurrence and management of the trigemino-cardiac reflex (TCR) defined as the phenomenon of abrupt drops in heart rate (HR) and blood pressure during skull base surgery. Method One hundred patients underwent skull base surgery for various lesions were recruited and great attention was paid to heart rate and blood pressure throughout the surgical procedure to screen intraoperative TCR. Result Twelve patients had TCR intro-operatively, all patients showed abrupt drops in HR of 38% from a mean of 78 beats/min to a mean of 49 beats/min, mean arterial blood pressure (MABP) decreased 33% from a mean of 93 mmHg to a mean of 60 mmHg, respectively. TCR was resolved spontaneously in eight patients, but had to be offset by intraoperative administration of relatively higher dose atropine in another four patients. Conclusion (1) Manipulation at or near the trigeminal nerve during the skull base surgery may cause TCR, even if premedication with anticholinergic drug is used; (2) cessation of irritation from surgical manipulation to disrupt the reflex is the most important step to offset TCR; (3) continuous, especially repeated TCR in some rare cases occasionally necessitates the administration of high dose atropine.