Suxamethonium is a depolarising muscle relaxant used to rapidly gain optimal intubating conditions. It is normally metabolised within 5 minutes by plasma cholinesterase. Some patients lack this enzyme or have an altered enzyme that does not metabolise the suxamethonium as rapidly. These patients may remain paralysed for a prolonged period after a standard dose of suxamethonium and rely on renal elimination. This condition is often referred to as suxamethonium apnea