Time course of potentiation of mivacurium by halothane and isoflurane in children.
We studied 40 children, aged 1-15 yr, to analyse the time course of potentiation of mivacurium produced by halothane and isoflurane. A steady infusion requirement of mivacurium to maintain 90% neuromuscular block was established during thiopentone-alfentanil-nitrous oxide-oxygen anaesthesia. Patients were then allocated randomly to receive 1 MAC end-tidal concentration of either halothane (group Hal) or isoflurane (group Iso) while neuromuscular block was maintained at 90%. Both volatile agents decreased the infusion requirements of mivacurium in an exponential manner in that maximal potentiation occurred only after 30-80 min. Maximal reduction in infusion rate (32% in group Hal and 70% in group Iso; P < 0.0001) did not depend on the age of the child but became established sooner the younger the child in the case of isoflurane (P = 0.002).
Meretoja
O A
OA
Department of Anaesthesiology, Children's Hospital University of Helsinki, Finland.
Wirtavuori
K
K
Taivainen
T
T
Olkkola
K T
KT
D000293:Adolescent; D000367:Age Factors; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D004334:Drug Administration Schedule; D004357:Drug Synergism; D006221:Halothane / Q000494:pharmacology*; D006801:Humans; D007223:Infant; D007530:Isoflurane / Q000494:pharmacology*; D007546:Isoquinolines / Q000494:pharmacology*; D000077590:Mivacurium; D009469:Neuromuscular Junction / Q000187:drug effects*; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*
D018685:Anesthetics, Inhalation; D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D000077590:Mivacurium; D007530:Isoflurane; D006221:Halothane