[Delayed trigeminocardiac reflex after maxillofacial surgery: case report]

Trigeminocardiac reflex is a physiological phenomenon that may occur in head and neck surgery, and is usually benign. However, it may present with exaggerated responses with severe morbidity.

Male patient, 26 years old, candidate for surgical treatment of zygomatic-orbital complex fracture. The surgery with bilateral nasal packing placed at the end of the procedure was uneventful. After being admitted to the post-anesthesia care unity, the patient complained of shortness of breath and nausea. Pulse oximetry fell below 90% in ambient air, and 100% O₂ was then offered through a Hudson mask. He showed no improvement in oximetry and developed a worsening dyspnea, diffuse wheezing, reduced heart rate, and blood pressure. Atropine was given, which raised the heart rate, but without resolution of hypotension and bronchospasm. Our suspicion was of a trigeminal-cardiac reflex, and then the removal of the nasal packing was done with complete remission of the signs and symptoms.

Florian Kratschmer (1870) was the first to describe the influences of nasal mucosal reflexes on respiration and circulation, which became known as Kratschmer's reflex. It is a reflex arc whose afferent originates in the nerve endings of the trigeminal nerve. The clinical presentation of trigeminocardiac reflex is the occurrence of sudden bradycardia, hypotension, apnea, and gastric hypermotility.

Trigeminocardiac reflex may be a protective neurogenic, oxygen-conserving response with low morbidity, however, exacerbated in certain situations. The interaction between surgeon and anesthesiologist, together with a careful monitoring of blood pressure and heart rate are fundamental for diagnosis and treatment.