Dose-response relation and time course of action of pipecuronium in patients anesthetized with nitrous oxide and sevoflurane.

The dose-response relation of pipecuronium, the time course of its neuromuscular blocking effects, and the reversibility of the residual block by neostigmine have been investigated in patients under sevoflurane/N2O Anesthesia using a neuromuscular transmission analyzer (Accelograph, Biometer, Denmark). After an initial dose of pipecuronium (0.04 mg.kg(-1), i.v.), the maximum block rate, onset time, the time from administration until 25% recovery and 50% recovery of control twitch height of the first response to train-of-four nerve stimulation and the interval time of administration of maintenance dose (0.005 mg.kg(-1), i.v.) were 93.7 +/- 7.68%, 5.0 +/- 1.84, 55.4 +/- 23.92, 73.0 +/- 29.44 and 38.7 +/- 15.50 minutes, respectively. The average intubation score (excellent; 0, good; 1 fair; 2, poor; 3) was 0.63 +/- 0.56 at the level of 95.88 +/- 5.06% block. Neostigmine (1.5 mg) promptly reversed the residual neuromuscular blockade induced by pipecuronium (reversal time: 10.1 +/- 2.98 minutes). No side effects attributable to pipecuronium was seen in this study. In conclusion, pipecuronium is a very useful nondepolarizing neuromuscular blocking agent especially for moderately long surgical procedure over 4-5 hours.