International journal of physiology, pathophysiology and pharmacology
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Int J Physiol Pathophysiol Pharmacol · Jan 2015
Sevoflurane enhances neuromuscular blockade by increasing the sensitivity of skeletal muscle to neuromuscular blockers.
The aim of this study was to investigate the effects of sevoflurane on skeletal muscle contractility. In the first part, twenty-two American Society of Anesthesiology (ASA I-II) female adult patients undergoing elective hysterectomy surgery inhaled sevoflurane 1.0, 1.5 and 2.0 minimum alveolar concentrations (MAC) in succession. Neuromuscular function was assessed at each dose. ⋯ Compared to group 1, there was no significant difference in atracurium onset time (time to reach TOF ratio = 0.25) in group 2 ( 5.6 ± 1.8 min vs. 6.5 ± 1.7 min, P>0.05), or degree of adductor pollicis block (subject number with TOF ratio = 0, 5 vs. 2 subjects, p = 0.3). However, inhaling 1.5 or 2.0 MAC sevoflurane decreased atracurium onset time (4.6 ± 1.5 min and 4.0 ± 1.3 min vs. 6.5 ± 1.7 min, P<0.01 and P<0.001, respectively), and enhanced the block degree (9 and 10 vs. 2 subjects, P<0.001) compared with group 1. Sevoflurane has no direct effects on the adductor pollicis contractility, but increased the skeletal muscle sensitivity to atracurium.