Trigeminocardiac Reflex in Maxillofacial Trauma Surgery: An Observational Study

In numerous experimental studies, authors have studied the autonomic responses triggered by the electrical, mechanical, or chemical stimulation of the trigeminal nerve system. This study aims to evaluate the incidence and duration of trigeminocardiac reflex (TCR) during various procedures of maxillofacial surgery. It also aims to evaluate the severe events of TCR during surgical procedures and identifying the predisposing factors and thereby decreasing the potential risk in maxillofacial surgery.

Occurrence of the TCR is considered if there is a 20% or more decrease in heart rate and mean arterial blood pressure in response to an adequate stimulus. Pre-operative baseline haemodynamic values, including heart rate, pulse rate, mean arterial pressure, systolic blood pressure, and diastolic blood pressure was recorded of 106 subjects undergoing oral and maxillofacial surgery under general anaesthesia. All episodes of bradycardia and hypotension during the surgery were obtained and recorded (coinciding with surgical procedures). Ethical clearance from institution committee and informed consent from each subject prior to procedure were obtained.

Four subjects had TCR during the surgery, out of a total of 106 subjects. The maximum duration of the TCR recorded in our observation was 18 s. All four patients responded to injection on intravenous atropine after stopping manipulation in the surgical field.

The authors’ results show the possibility, although rare, of occurrence of a TCR during operating on the maxillofacial region.