, Volume 38, Issue 6, pp 757-760

Trigeminocardiac reflexes: maxillary and mandibular variants of the oculocardiac reflex

Abstract

Three case reports are presented to illustrate the existence and importance of reflex bradycardic responses that can occur during maxillofacial surgical procedures. All three patients were healthy young adults undergoing operations which did not include any manipulation of orbital structures. After the patients had been anaesthetized for some time and were haemodynamically stable, profound bradycardia or ventricular asystole occurred suddenly in response to manipulations of the bony structures of the maxilla or mandible, or dissection of, or traction on, the attached soft tissue structures. The parasympathetic supply to the face is carried in the trigeminal nerve. Alternative afferent pathways must exist via the maxillary and/or mandibular divisions, in addition to the commonly reported pathway via the ophthalmic division of the trigeminal nerve in the classic oculocardiac reflex. The efferent arc involves the vagus, regardless of which branch of the trigeminal nerve transmits the afferent impulses. All patients undergoing maxillofacial procedures should be monitored carefully for reflex bradycardia and ventricular asystole.

Résumé

Voici trois cas mettant en lumière l’existence d’une importante bradycardie réflexe pouvant survenir pendant une intervention chirurgicale maxillofaciale. Alors que l’anesthésie durait depuis un bon moment, que leur hémodynamie était stable, et en l’absence de manipulation des structures de l’orbite, nos trois patients, de jeunes adultes, devinrent sévèrement bradycardes ou asystoliques pendant la mobilisation du maxillaire supérieur ou inférieur ou la dissection/traction des tissus s’y rattachant. Le trijumeau assure l’innervation parasympathique de la face. On connaît bien le réflexe oculocardiaque qui passe par la branche ophtalmique du trijumeau. Les branches maxillaires et/ou mandibulaires du nerf peuvent done aussi transporter des afférences initiant un reflexe similaire avec efférence vagale. Soyons dorénavant aux aguets d’une bradycardie réflexe ou d’une asystolie ventriculaire lors des chirurgies maxillofaciales.