PROLONGED NEUROMUSCULAR BLOCK ASSOCIATED WITH MIVACURIUM

Mivacurium is a relatively new short-acting nondepolarizing neuromuscu lar blocker. A recommended dose of 0.15-0.2 mg kg(-1) provides trachea l intubating conditions within 2.5 min and duration of action of 15-30 min, making it a possible alternative to suxamethonium for short proc edures requiring tracheal intubation. However, in common with suxameth onium its metabolism depends primarily on plasma cholinesterase and it s duration of action is prolonged in patients with reduced plasma chol inesterase activity. We present a case of unexpected prolonged neuromu scular block in a child with previously undiagnosed plasma cholinester ase deficiency.