The time-course of action and recovery of rocuronium 0.3 mg x kg(-1) in infants and children during halothane anaesthesia measured with acceleromyography.

This study compares the time-course of action of neuromuscular paralysis after 0.3 mg x kg(-1) of rocuronium during nitrous oxide-halothane anaesthesia in children of three different age groups. With appropriate approval and informed consent from the parents, 51 children, ASA I-II, scheduled for elective surgery requiring muscle relaxation, were studied. The children were assigned to three groups according to age: group 1, 0-6 months; group 2, 6-24 months; and group 3, > 24 months of age. Induction of anaesthesia and tracheal intubation were performed under halothane anaesthesia. Acceleromyography of the thumb was recorded after supramaximal transcutaneous ulnar nerve stimulation using train-of-four (TOF) stimulation. Rocuronium 0.3 mg x kg(-1) was given as a rapid i.v. bolus prior to surgical incision. The onset time (time to max effect) and the maximal depth of the block, the time to recovery of the first twitch (T1) to 25% and 75% of its baseline, the recovery index (RI), and the time to recovery of the TOF ratio to 70% after the end of injection of rocuronium were all measured. The mean (SD) age of the children in groups 1, 2, and 3 was 3.1 (1.6), 12.6 (3.7), and 63 (46) months, respectively. The onset time of rocuronium was 47 (12), 83 (42) and 94 (12) s, respectively, in groups 1, 2, and 3 (P<0.05 group 1 vs. 2 and 3). One hundred percent block was achieved in 18/19 patients in group 1, 12/14 in group 2 and 6/18 in group 3. The times to 25% and 75% recovery of T1 and the time for recovery of the TOF ratio to 70% were all significantly longer in groups 1 and 2 compared to group 3. Group 1 and 2 showed no significant differences in recovery times. The RI was significantly prolonged in group 1 versus 3. The authors conclude that rocuronium 0.3 mg x kg(-1) during halothane anaesthesia causes more neuromuscular depression and has a longer duration of action in infants than in children older than 2 years.

RCT Entities:   Population Interventions Outcomes