Effect of a small priming dose on myoclonic movements after intravenous anaesthesia induction with Etomidate-Lipuro in children.

摘要

BACKGROUND: In children, the incidence of injection pain at i.v. anaesthetic induction with Etomidate-Lipuro is low when compared with propofol mixed with lidocaine (5%). However, the incidence of involuntary myoclonic movements (MM) after induction of anaesthesia is higher compared with propofol (85% vs. 15%). In adults, the incidence of MM is reported to be significantly reduced if a small priming dose is administered immediately before the main injection of etomidate. The aim of this prospective, randomized, double-blind, placebo-controlled clinical trial was to investigate if a small priming dose of etomidate effectively can reduce the incidence of MM also in children. METHODS: Eighty ASA I-II children (1-15 yr) were randomized to receive either a small priming dose of etomidate (0.03 mg kg(-1)) or a lipid emulsion placebo. A standardized induction dose of etomidate (0.3 mg kg(-1)) was administered 60 s after the priming dose. The occurrence and severity (observational score 0-3) of MM was defined as the primary endpoint of the study and was recorded during a 2 min period after induction of anaesthesia. A post hoc analysis was performed regarding the incidence of MM with respect to age. RESULTS: No difference in the occurrence or severity of MM was found between the two study groups, the total incidence of MM being 73.8% (95% confidence interval: 62.7-83.0%). The incidence of MM (score > 0) was found to be statistically higher in the age group 5-10 yr compared with <5 yr; and >10 yr (P=0.0008 and 0.01730, respectively). The MM scores were highest in patients aged 5-10 yr (P=0.0021). CONCLUSIONS: Children in the age range of 5-10 yr appear to be especially prone to react with involuntary MM after i.v. induction of anaesthesia with etomidate. The use of a small, non-sedative, priming dose did not influence the incidence of involuntary MM after i.v. induction of anaesthesia with etomidate in children 1-15 yr of age.