Methods: The pharmacodynamics of mivacurium preceded by atracurium or cisatracurium were evaluated in 45 ASA I children (2-13 years of age) during propofol alfentanil-N2O/O2 anaesthesia. Neuromuscular response was recorded by adductor pollicis EMG. Children were randomized to receive two doses of atracurium (350 and 70 μg kg−1 in Group AM), cisatracurium (64 and 10 μg kg−1 in Group CM) or mivacurium (200 and 100 μg kg−1 in Group MM) followed by a final dose of mivacurium 100 μg kg−1. The second and third doses of the muscle relaxants were administered at 25% EMG recovery. The data were compared by Kruskal-Wallis and Mann-Whitney U-tests.
Results: The EMG recovery times were significantly shorter in Group MM than in the two other groups (Table 1). No differences in recovery times existed between Group AM and Group CM.
Conclusion: The duration of effect of mivacurium was prolonged by 200% if preceded by either atracurium or cisatracurium, suggesting strong potentiation of mivacurium by both atracurium and cisatracurium in children.
This publication has been supported by educational grants from Glaxo Wellcome and Organon Teknika NV.
Session 4:23 August, 16:30-17:30 h