Variability of duration of action of neuromuscular-blocking drugs in elderly patients

• Published in: Acta anaesthesiologica Scandinavica Vol. 49; no. 3; pp. 312 - 315
• Main Authors: Arain, S. R., Kern, S., Ficke, D. J., Ebert, T. J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK; Malden, USA Blackwell Publishing Ltd/Inc 01.03.2005; Blackwell
• Subjects: Age; Aged; Aging - metabolism; Analysis of Variance; Androstanols - pharmacology; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Atracurium - analogs & derivatives; Atracurium - pharmacology; Biological and medical sciences; cisatracurium; Dose-Response Relationship, Drug; Female; Humans; Male; Medical sciences; Neuromuscular Blocking Agents - pharmacology; Neuromuscular Nondepolarizing Agents - pharmacology; recovery; rocuronium; Time Factors; variability; vecuronium; Vecuronium Bromide - pharmacology; Human; cisatracurium; Variability; Anesthesia; rocuronium; recovery; Elderly; Neuromuscular blocking; Age; vecuronium; Duration of action
• ISSN: 0001-5172; 1399-6576
• DOI: 10.1111/j.1399-6576.2005.00634.x

Background:  Steroid‐based, non‐depolarizing neuromuscular‐blocking (NMB) drugs (e.g. rocuronium, vecuronium) are characterized by organ‐dependent elimination and significantly longer durations of action in elderly compared to young patients. Cisatracurium is a benzylisoquinolinium NMB drug with a duration of action not altered by ageing. The objective of the study was to determine if elderly patients had less variability in duration of action with 2 × ED95 of cisatracurium compared to equipotent doses of rocuronium or vecuronium. Methods:  Informed consent was obtained from 66 elderly patients with normal renal and liver function. Preoperative midazolam (1 mg) was given IV. The anaesthestic induction was with 5 mg kg−1 thiopental and 2 µg kg−1 fentanyl. The patients received 0.6 mg kg−1 rocuronium, 0.1 mg kg−1 vecuronium or 0.1 mg kg−1 cisatracurium. Anaesthetic maintenance was with sevoflurane in oxygen/nitrous oxide. Neuromuscular‐blocking duration of action was defined as the return of T1 twitch height to 25% of control. Variability was determined by subtracting the actual duration of action from the mean duration of action for each drug. Results:  The durations of action (range, min) were: cisatracurium, 37–81; vecuronium, 35–137; and rocuronium, 33–119. The median of the variability of duration was significantly less with cisatracurium (7 min) compared to vecuronium (18 min) and rocuronium (18 min) (P < 0.05). Conclusion:  When used with sevoflurane/N2O, there was a two‐fold greater variability of duration of neuromuscular blockade in elderly patients receiving rocuronium or vecuronium compared with cisatracurium.