Mivacurium in children with Duchenne muscular dystrophy

The authors retrospectively reviewed their experience with mivacurium for neuromuscular blockade in seven children with Duchenne muscular dystrophy. Mivacurium was administered to seven children ranging in age from 8.3 to 14.4 years and in weight from 29 kg to 68 kg during either posterior spinal fusion or lower extremity release. An initial bolus dose of 0.2 mg·kg^?1 was followed by a continuous infusion. Neuromuscular blockade was monitored with a standard twitch monitor and the TOF (2 Hz for 2 s). Complete suppression of all four twitches occurred in 1.5 to 2.6 min. The continuous infusion was started with the return of the first twitch and adjusted to maintain one twitch. Time to recovery of the first twitch varied from 12 to 18 min. Continuous infusion requirements varied from 3 to 20 μg·kg^?1 with an average for the case of less than 10 μg·kg^?1 min^?1 in five of the seven patients. A moderate increase in sensitivity to mivacurium in this patient population is suggested by a decrease in infusion requirements and a prolonged effect following the initial dose.