Prolonged mivacurium neuromuscular blockade in a newborn.

Mivacurium is a short acting non-depolarising neuromuscular blocking agent. Short duration of action is due to a rapid hydrolysis by plasma cholineste rase (CHe). The duration of neuromuscular blockade can be prolonged by an a bnormal variant of CHe. We report a case of a newborn with neuromuscular bl ockade for a duration of 8 hours following mivacurium 0.2 mg.kg(-1), CHe ac tivity values were not contributive for the diagnosis. The diagnosis was ob tained with molecular study showing the new-born homozygocity. The whole fa mily was heterozygous. This case emphasises the lack of precision of CHe ac tivity measurement during the first 6 months of life. (C) 1998 Elsevier, Pa ris.