A case of succinylcholine apnoea - a forgotten episode in current practice

Abstract

Apnoea and prolonged paralysis after succinylcholine administration is not an uncommon occurrence in anaesthetic practice. It occurs due to inherited or acquired deficiency of butyrylcholinesterase. Suxamethonium (succinylcholine) is a depolarizing neuromuscular blocker used for rapid sequence intubation in anesthesia. It acts quickly, causing temporary paralysis, but in some individuals, a deficiency or abnormality in the enzyme pseudocholinesterase (also called butyrylcholinesterase) can result in prolonged paralysis, a condition known as suxamethonium apnea. Pseudocholinesterase deficiency can be inherited or acquired, and patients with this condition cannot efficiently metabolize suxamethonium, leading to delayed recovery from muscle paralysis. The clinical presentation typically includes prolonged apnea and muscle weakness long after the expected recovery time, often requiring mechanical ventilation until the effects of the drug wear off. Suxamethonium is used to achieve quality relaxation for the orotracheal intubation. It is considered as a safe drug but can rarely lead to serious adverse effects, such as hyperkalaemia, malignant hyperthermia, and prolonged apnoea. Prolonged apnoea may occur due to pseudocholinesterase deficiency, old age, impaired liver or renal function and medication interactions.