AB230. SOH25_AB_117. Suxamethonium apnoea in a model 2 hospital: a case report

Background: Suxamethonium apnoea is a rare anaesthetic emergency, occurring in approximately 1 in 2,800 patients. Suxamethonium is a depolarising muscle relaxant with a normal duration of action of 3–8 minutes as it is rapidly broken down by plasma cholinesterase. In some patients, due to genetic predispositions or acquired conditions, this enzyme can be deficient, leading to a prolonged period of muscle relaxation lasting hours.

Case Description: A 6-year-old boy was undergoing routine elective surgery in a model 2 hospital. Upon induction, they experienced laryngospasm not responding to continuous positive airway pressure and deepening of anaesthesia. Suxamethonium was administered to resolve the laryngospasm and perform emergency intubation. Upon cessation of the surgery, one hour post the administration of suxamethonium, the patient had complete residual paralysis, confirmed with neuromuscular monitoring showing a train of four count of 0. Suxamethonium apnoea was suspected. A paediatric intensive care unit (ICU) was consulted, and the Irish Paediatric Acute Transport Service contacted for transportation. Upon their arrival 2.5 hours post suxamethonium, the train of four count had returned to 4, signifying the return of muscular power. The patient was successfully extubated and transferred to University Hospital Limerick (UHL) for routine monitoring.

Conclusions: Suxamethonium apnoea is a rare anaesthetic emergency. Approximately 4% of patients have abnormal genes leading to a prolonged block. Upon recognition of suxamethonium apnoea, anaesthesia should be maintained to prevent awareness, and the relevant ICU contacted for possible transfer. Blood testing for plasma cholinesterases should be performed for the patient and first-degree family members. Mivacurium should be avoided in susceptible individuals.

Keywords: Peripheral neuromuscular monitoring; suxamethonium apnoea; case report