title: Mivacurium infusion during nitrous oxide-isoflurane anesthesia: a comparison with nitrous oxide-opioid anesthesia.
abstract: OBJECTIVE
  To determine the potentiation of the neuromuscular blockade induced by a titrated infusion of mivacurium in the presence of isoflurane versus a nitrous oxide (N2O)-opioid anesthesia.
  
  
  METHODS
  An open-label, controlled study.
  
  
  METHODS
  The inpatient anesthesia service of two university medical centers.
  
  
  METHODS
  Thirty adults divided into two groups.
  
  
  METHODS
  An intravenous infusion of mivacurium during anesthesia with N2O-opioid or N2O-isoflurane.
  
  
  RESULTS
  A neuromuscular blockade was monitored by recording the electromyographic activity of the adductor pollicis muscle resulting from supramaximal stimulation at the ulnar nerve at 2 Hz for 2 seconds at 10-second intervals. The mivacurium infusion rate was significantly less in the presence of isoflurane [4.0 +/- 0.8 micrograms/kg/min (mean +/- SEM)] than during N2O-opioid anesthesia (6.4 +/- 0.6 micrograms/kg/min). The recovery rates did not differ between anesthetic groups. After the termination of the infusion, spontaneous recovery to T4/T1 of at least 0.75 occurred in an average of 17.9 +/- 1.5 minutes, with a mean recovery index (T25-75) of 6.0 +/- 0.7 minutes.
  
  
  CONCLUSIONS
  Isoflurane anesthesia reduces the infusion rate of mivacurium required to produce about 95% depression of neuromuscular function.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, University of Pittsburgh School of Medicine, PA.
authors.forename: D M
authors.initials: DM
authors.lastname: Powers
authors.forename: B W
authors.initials: BW
authors.lastname: Brandom
authors.forename: D R
authors.initials: DR
authors.lastname: Cook
authors.forename: R
authors.initials: R
authors.lastname: Byers
authors.forename: J B
authors.initials: JB
authors.lastname: Sarner
authors.forename: K
authors.initials: K
authors.lastname: Simpson
authors.forename: S
authors.initials: S
authors.lastname: Weber
authors.forename: S K
authors.initials: SK
authors.lastname: Woelfel
authors.forename: V J
authors.initials: VJ
authors.lastname: Foster
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D004357:Drug Synergism; D005260:Female; D005283:Fentanyl; D006801:Humans; D007262:Infusions, Intravenous; D007530:Isoflurane; D007546:Isoquinolines; D008297:Male; D008875:Middle Aged; D000077590:Mivacurium; D009469:Neuromuscular Junction / Q000187:drug effects*; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage*; D009609:Nitrous Oxide
chemical_list: D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D000077590:Mivacurium; D007530:Isoflurane; D009609:Nitrous Oxide; D005283:Fentanyl