Time-course of action of rocuronium 0.3 mg.kg-1 in children with and without endstage renal failure.

Background: The time-course of the neuromuscular effects of rocuronium 0.3 mg.kg-1 during nitrous oxide-halothane anaesthesia in children with and without renal failure is unknown. This study compared the neuromuscular blocking effects in these groups.

Methods: The study was approved by the Hospital Ethical Committee. In the control group, 14 healthy children without renal disease were scheduled for various elective surgical procedures. Sixteen children with endstage renal failure, 14 of whom were already on renal dialysis, were scheduled for (re)placement of dialysis catheters (n=14) or for renal transplantation (n=2). Anaesthesia was induced and maintained with halothane and nitrous oxide in oxygen. Acceleromyographic thumb adduction after supramaximal ulnar nerve stimulation was recorded using train-of-four stimulation every 15 s. The onset time, the time to recovery of the first twitch to 25% or 75% and to recovery of a train-of-four ratio of 0.7 after rocuronium 0.3 mg.kg-1 were measured. Statistical analysis was performed with Student's t-test. P < 0.05 was considered statistically significant.

Results: The onset time was longer in children with renal failure (139 s, SD=71) than in control children (87 s, SD=43) (P=0.02). There were no significant differences in the duration of action of rocuronium between children without renal failure and in 15 out of 16 children with renal failure.

Conclusions: In children with renal failure, aged over 1 year, a single bolus dose of rocuronium 0.3 mg.kg-1 does not cause a prolonged block, but has a slower onset than in healthy children.