Vecuronium Infusion Requirements in Children During Halothane-Narcotic-Nitrous Oxide, Isoflurane-Narcotic-Nitrous Oxide, and Narcotic-Nitrous Oxide Anesthesia

Abstract

We were interested in determining the infusion rate of vecuronium required to maintain approximately 95% neuromuscular blockade in children during halothane-narcotic-nitrous oxide (0.8% end-tidal concentration), isoflurane-narcotic-nitrous oxide (1.0% end-tidal concentration), or narcotic-nitrous oxide anesthesia. Neuromuscular blockade was monitored by recording the electromyographic activity (Datex NMT) of the adductor pollicis muscle resulting from supramaximal stimulation of the ulnar nerve at 2 Hz for 2 s at 10-s intervals. Effective vecuronium infusion requirements averaged 1.5 +/- 0.1 micrograms.kg-1.min-1 (mean +/- SEM) during isoflurane-narcotic-nitrous oxide anesthesia, 1.9 +/- 0.1 micrograms.kg-1.min-1 during halothane-narcotic-nitrous oxide anesthesia, and 2.4 +/- 0.3 micrograms.kg-1.min-1 during narcotic-nitrous oxide anesthesia. Infusion requirements significantly decreased after the first 30 min of infusion in the presence of both potent inhalation anesthetics, but did not change with time during narcotic-nitrous oxide anesthesia. There was no evidence of decreasing infusion requirements during prolonged vecuronium infusion (2.5 h). There was no difference in the rate of spontaneous or pharmacologically induced recovery between anesthetic groups. The mean recovery index (T25-75) after termination of the infusion was 13.7 min.

The advancement of pediatric anesthesia pharmacology: David Ryan Cook (scions, serendipity, and six degrees of separation)

“…They identified the sensitivity of infants to nondepolarizing neuromuscular blockers 12 and the relative resistance to children (larger ED 95 ) when compared to adults. 7,13 The ED 95 of doxacurium was measured in children 2-10 years old and was larger than the historically recorded ED 95 in adults administered similar anesthetic agents. 13 They also identified a similar relationship between age and vecuronium infusion rates.…”

“…Dr Cook and his research team, comprising Drs. Barbara Brandom, Susan Woelfel, Peter Davis, and Richard Stiller, went on to investigate the pharmacology of nondepolarizing neuromuscular blockers including vecuronium, mivacurium, atracurium, and doxacurium . They helped define the dose response, duration, pharmacokinetics, and clinical side effects of these agents in neonates, infants, and children.…”

“…They helped define the dose response, duration, pharmacokinetics, and clinical side effects of these agents in neonates, infants, and children. They identified the sensitivity of infants to nondepolarizing neuromuscular blockers and the relative resistance to children (larger ED 95 ) when compared to adults . The ED 95 of doxacurium was measured in children 2‐10 years old and was larger than the historically recorded ED 95 in adults administered similar anesthetic agents .…”

“…They also identified a similar relationship between age and vecuronium infusion rates. Children between the ages of two and 10 required a larger infusion rate than different adult age groups during a narcotic‐nitrous anesthetic . They defined the effective doses for all the commonly used neuromuscular blockers used at the time.…”

“…18 4 Defined the pharmacokinetic and pharmacodynamics effects of volatile anesthetics in pediatric patients. 30 6,7,[11][12][13] They helped define the dose response, duration, pharmacokinetics, and clinical side effects of these agents in neonates, infants, and children. They identified the sensitivity of infants to nondepolarizing neuromuscular blockers 12 and the relative resistance to children (larger ED 95 ) when compared to adults.…”