Propofol-Induced Seizure

Abstract

Approximately 30% of ambulatory anesthesia services for diagnostic or therapeutic procedures in the USA are performed under Monitored Anesthesia Care (MAC). Propofol is a widely used agent for MAC because of its rapid, short-acting sedative/hypnotic effects. This case report is about seizure like activity in the recovery period attributed to propofol noted in a lady who underwent MAC for endoscopic evaluation. A 39 year old female with history of hypertension, persistent GERD symptoms and melena presented for EGD/ Colonoscopy under MAC. In the anesthetic room, pre-oxygenation was performed and then induced with 400mg of propofol. She had an EGD and colonoscopy which she tolerated well. In the post recovery area, she was noted to have generalized jerky body movements, rolled her eyes to the back and became unconscious. Vital signs were stable. She was noted to be post ictal with gradual improvement in mental status. Electrolytes and blood glucose level were in normal ranges. Ct head performed did not show any acute event. Evaluation by neurology revealed a normal neurological exam. Neurology recommended an EEG and a follow up in the neuro clinic. Anti-epileptic drugs were not prescribed. Propofol is a widely used agent for anesthesia, sedation and as an anticonvulsant in status epilepticus. Given its short half-life even after prolonged infusions, it is widely used in MAC. MAC results in less physiologic disturbance and allows for more rapid recovery than general anesthesia.Propofol has been noted to induce abnormal neuromuscular events during induction, maintenance or emergence from propofol anesthesia and sedation. Unresponsiveness, myoclonus, opisthotonus, dystonia, ataxia and seizures have all been described. Several hypotheses have been put forward to explain the paradoxical response to propofol including: desensitization of inhibitory receptors leading to refractoriness in the inhibitory glycinergic and GABAergic pathways and imbalance between cholinergic and dopaminergic activity at the level of basal ganglia. Our patient had no previous history of seizures.There is no clear consensus regarding the prevention and identifying patients at risk for such adverse events. Seizure like phenomenon has been reported with propofol administration in both healthy and epileptic patients. Propofol, though a great agent for MAC is a known cause of seizure like phenomenon. More needs to be known about the mechanism of this complication and identifying patients at risk.