Duration of exposure to sevoflurane affects dose–response relationship of vecuronium

• Published in: British journal of anaesthesia : BJA Vol. 85; no. 5; pp. 732 - 734
• Main Authors: Suzuki, T., Iwasaki, K., Fukano, N., Hariya, S., Saeki, S., Ogawa, S.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.2000; Oxford University Press; Oxford Publishing Limited (England)
• Subjects: Adult; anaesthetics volatile, sevoflurane; Anesthetics, Inhalation - pharmacology; Anesthetics. Neuromuscular blocking agents; Biological and medical sciences; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Interactions; Female; Humans; Male; Medical sciences; Methyl Ethers - pharmacology; Middle Aged; neuromuscular block, vecuronium; Neuromuscular Junction - drug effects; Neuromuscular Nondepolarizing Agents - pharmacology; Neuropharmacology; pharmacology, dose–response relationship; Pharmacology. Drug treatments; Sevoflurane; Vecuronium Bromide - pharmacology; anaesthetics volatile, sevoflurane; neuromuscular block, vecuronium; pharmacology, dose–response relationship; pharmacology, dose–response relationship; neuromuscular block, vecuronium; anaesthetics volatile, sevoflurane; Volatile compound; Human; Steroid; Drug combination; General anesthesia; Duration; Neuromuscular transmission; Vecuronium bromide; Dose activity relation; Sevoflurane; Non depolarisant myorelaxant; General anesthetic; Drug interaction; Neuromuscular blocking; Monitoring; Halogen Organic compounds
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/85.5.732

The purpose of this study was to quantify the relationship between the dose–response curve of vecuronium and duration of exposure to an end-tidal concentration of 1.7% sevoflurane in 67% nitrous oxide and oxygen. Forty adult patients, in groups of 10, were allocated randomly to receive vecuronium by a cumulative dose method at intervals of 15 min (group 15), 30 min (group 30), 60 min (group 60) or 90 min (group 90) after starting inhalation of sevoflurane. Neuromuscular function was monitored by acceleromyographic train-of-four (TOF) responses of the adductor pollicis muscle to ulnar nerve stimulation. Dose–response curves were constructed by least-squares regression analysis and the effective doses of vecuronium (ED50, ED90 and ED95) were estimated and compared between groups. Mean (sem) ED50, ED90 and ED95 were 16.8 (0.5), 32.6 (1.7) and 40.9 (2.4) μg kg−1, respectively, in group 15; 10.6 (1.0), 20.8 (1.7) and 26.2 (2.2) μg kg−1, respectively, in group 30; 11.2 (1.1), 21.7 (1.6) and 27.3 (1.8) μg kg−1, respectively, in group 60; and 11.0 (1.1), 21.7 (1.6) and 27.5 (1.9) μg kg−1, respectively, in group 90. The values obtained in group 15 were significantly higher than those in the other three groups (P<0.05). The results indicate that the duration of sevoflurane anaesthesia influences the dose–response of vecuronium and 30 min inhalation of 1.7% end-tidal concentration is sufficient to achieve a stable potentiating effect.