Management of masseter spasm after induction of general anaesthesia in a patient with depressive disorder on selective serotonin reuptake inhibitor treatment.

Masseter spasm after induction of anaesthesia can be generally defined as a marked difficulty in manual mouth opening that interferes and impedes direct laryngoscopy and tracheal intubation without the presence of temporomandibular joint dysfunction. Several factors have been implicated in the literatures responsible for causing masseter spasm including use of non-depolarizing muscle relaxants, selective serotonin reuptake inhibitor and anxiety. Our case is the first to report masseter spasms with the use of Cis-atracurium in a patient on antidepressant depressant treatment with sertraline and having extreme preoperative anxiety. Anaesthesiologist should be aware of this complication when dealing with anxious patients on antidepressant therapy during induction of anaesthesia. Masseter spasm with locked jaw, can be a potential life-threatening situation particularly in scenarios of "cannot- ventilate-cannot intubate".