COMPARISON OF SUXAMETHONIUM AND DIFFERENT COMBINATIONS OF ROCURONIUM AND MIVACURIUM FOR RAPID TRACHEAL INTUBATION IN CHILDREN

The use of suxamethonium in children is associated with undesirable si de effects. The synergistic effect of a rocuronium-mivacurium combinat ion can be considered as an acceptable alternative to suxamethonium in clinical practice. The calculated ED50 of the rocuronium-mivacurium m ixture was only 62% of the predicted value assuming a purely additive interaction. The use of this combination has not been evaluated in chi ldren. In this two-part study, we assessed the intubating conditions a nd pharmacodynamics of suxamethonium, rocuronium, mivacurium or a rocu ronium-mivacurium combinations in children. We studied 120 ASA I child ren of both sexes, aged 3-10 yr. Children were premedicated with trime prazine 2 mg kg(-1) orally, and received fentanyl 2 mu g kg(-1) and pr opofol 2 mg kg(-1) for induction of anaesthesia. They were allocated r andomly to receive one of the following drugs or drug combinations: su xamethonium 1.0 mg kg(-1), mivacurium 0.2 mg kg(-1), rocuronium 0.6 or 0.9 mg kg(-1), mivacurium 0.1 mg kg(-1) with rocuronium 0.3 mg kg(-1) , or mivacurium 0.15 mg kg(-1) with rocuronium 0.45 mg kg(-1). In part 1, 60 s after administration of the neuromuscular blocking drug or dr ug combination, tracheal intubation was performed in 60 children by mi micking rapid sequence induction, and intubating conditions were evalu ated by a blinded investigator according to a standard score. In part 2, neuromuscular monitoring was established before administration of n euromuscular blocking agent(s) and the time from injection of drug or drug combination until complete ablation of T1 (onset) and recovery of T1 to 25% (duration) were recorded in another 60 children. The freque ncy of distribution of excellent or good intubating conditions in the higher dose of rocuronium and the combination groups were similar to t hose in the suxamethonium group, but significantly different (P<0.05) from those in the mivacurium group. Mean onset time was faster in the suxamethonium (55.1 (so 11.4) s), rocuronium 0.9 mg kg(-1) (70.5 (37.7 ) s), mivacurium 0.1 mg kg(-1) with rocuronium 0.3 mg kg(-1) (67 (35.9 ) sf and mivacurium 0.15 mg kg(-1) with rocuronium 0.45 mg kg(-1) (55 (26.7) s) groups compared with the mivacurium 0.2 mg kg(-1) (116(26.8) sf and rocuronium 0.6 mg kg(-1) (97.9 (29) s) groups. This study demo nstrated that the combination of rocuronium 0.45 mg kg(-1) and mivacur ium 0.15 mg kg(-1) could possibly be considered as an acceptable alter native to suxamethonium when rapid sequence induction of anaesthesia i s indicated in children because it provides uniform excellent intubati ng conditions and complete neuromuscular block in <60 s.