Comparison of the neuromuscular effects of mivacurium and suxamethonium in infants and children.
We compared both the time course of neuromuscular blockade and the cardiovascular side-effects of suxamethonium and mivacurium during halothane and nitrous oxide anaesthesia in infants 2-12 months and children 1-12 years of age. Equipotent doses of mivacurium and suxamethonium were studied; 2.2 x ED95 was used in four groups of infants and children, while 3.4 x ED95 was used in two groups of children. Onset of neuromuscular block in infants was not significantly faster with suxamethonium than with mivacurium (P = 0.2). In all infants given suxamethonium, intubating conditions were excellent, while, in 6/10 infants given mivacurium, intubating conditions were excellent. Onset of complete neuromuscular block in children was significantly faster with suxamethonium, 0.9 min compared with mivacurium, 1.4 min (P < or = 0.05). Increasing the dose of suxamethonium or mivacurium in children to 3.4 x ED95 did not change the onset of neuromuscular block. Recovery of neuromuscular transmission to 25% of initial twitch height (T25) in infants and children was significantly faster after suxamethonium than after mivacurium, at 2.5 and 6 min, respectively (P < or = 0.05). In children given 3.4 x ED95 of suxamethonium or mivacurium, recovery from neuromuscular block was almost identical with the dose of 2.2 x ED95, with spontaneous recovery to T25 prolonged by only 0.5 min. No infant or child had hypotension after the mivacurium bolus dose.
Department of Anesthesiology, Children's Hospital of Pittsburgh, PA 15213-2583, USA.
D R
DR
Cook
B J
BJ
Gronert
S K
SK
Woelfel
D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000008:administration & dosage; D001794:Blood Pressure / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D002802:Cholinesterases / Q000097:blood; D006221:Halothane / Q000008:administration & dosage; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007022:Hypotension / Q000139:chemically induced; D007223:Infant; D007442:Intubation, Intratracheal; D007546:Isoquinolines / Q000008:administration & dosage*; D000077590:Mivacurium; D009467:Neuromuscular Depolarizing Agents / Q000008:administration & dosage*; D009469:Neuromuscular Junction / Q000187:drug effects; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage*; D009609:Nitrous Oxide / Q000008:administration & dosage; D013390:Succinylcholine / Q000008:administration & dosage*; D009435:Synaptic Transmission / Q000187:drug effects; D013997:Time Factors
D018685:Anesthetics, Inhalation; D007546:Isoquinolines; D009467:Neuromuscular Depolarizing Agents; D003473:Neuromuscular Nondepolarizing Agents; D000077590:Mivacurium; D002802:Cholinesterases; D013390:Succinylcholine; D009609:Nitrous Oxide; D006221:Halothane