title: Doxacurium chloride for neuromuscular blockade before tracheal intubation and surgery during nitrous oxide-oxygen-narcotic-enflurane anesthesia.
abstract: The neuromuscular effects of doxacurium (BW A938U) were studied in 36 patients, divided into four groups of 9 patients each, given doxacurium either 50 micrograms/kg (2 x ED95) 5 or 4 minutes or 80 micrograms/kg (3 x ED95) 4 or 3 minutes before tracheal intubation. Adequate neuromuscular relaxation permitted successful intubation at 5 minutes for doxacurium 50 micrograms/kg and at 4 minutes for 80 micrograms/kg. Time to 90% blockade was 5.4 +/- 1.5 minutes for doxacurium 50 micrograms/kg and 3.5 +/- 1.2 minutes for 80 micrograms/kg. Time to 25% spontaneous recovery was 84.7 +/- 54.3 minutes for doxacurium 50 micrograms/kg and 164.4 +/- 85.2 minutes for 80 micrograms/kg. Either neostigmine 45 micrograms/kg, neostigmine 60 micrograms/kg, or edrophonium 1000 micrograms/kg was given for reversal when T1 had spontaneously recovered to 25% of baseline level, T1 being the first response to repetitive train-of-four (TOF) stimuli (2 Hz for 2 seconds at 10-second intervals) expressed as percent of baseline level. The T4:T1 ratio is the amplitude of the fourth twitch relative to the first twitch in a TOF stimulus expressed as a ratio. T1 rapidly achieved 90% of baseline in 5-10 minutes after reversal of neuromuscular blockade. In contrast, the T4:T1 ratio lagged, recovering to a mean of 0.6 at 20 minutes when T1 was over 90% of baseline. Recovery patterns were not statistically significantly different (unpaired t-test) among the three reversal regimens. Therefore, the reversal data were pooled. No clinically significant hemodynamic effects occurred in any group.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota 55905.
authors.forename: R L
authors.initials: RL
authors.lastname: Lennon
authors.forename: M P
authors.initials: MP
authors.lastname: Hosking
authors.forename: P C
authors.initials: PC
authors.lastname: Houck
authors.forename: S H
authors.initials: SH
authors.lastname: Rose
authors.forename: D J
authors.initials: DJ
authors.lastname: Wedel
authors.forename: B E
authors.initials: BE
authors.lastname: Gibson
authors.forename: J A
authors.initials: JA
authors.lastname: Ascher
authors.forename: G D
authors.initials: GD
authors.lastname: Rudd
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000758:Anesthesia; D004737:Enflurane; D006801:Humans; D007442:Intubation, Intratracheal; D007546:Isoquinolines / Q000494:pharmacology*; D008875:Middle Aged; D009294:Narcotics; D009466:Neuromuscular Blocking Agents / Q000494:pharmacology*; D009609:Nitrous Oxide; D010100:Oxygen
chemical_list: D007546:Isoquinolines; D009294:Narcotics; D009466:Neuromuscular Blocking Agents; D004737:Enflurane; D009609:Nitrous Oxide; C049429:doxacurium; D010100:Oxygen