Abstract:

Objective      To observe the effects of sevoflurane on neuromuscular block induced by vecuronium. Methods      This study included 60 ASA Ⅰ or Ⅱ patients (aged 4060 yr, weighing 45-80kg) who underwent radial breast cancer surgery under general anesthesia. They were randomly divided into the sevoflurane group and the propofol group(n=30 in each). Anesthesia was induced by 8% sevoflurane with vital capacity and oxygen flow at 6L/min in the sevoflurane group or 2mg/kg of propofol in the propofol group. When the patients′ eyelash reflex disappeared in the two groups, 0.1mg/kg of vecuronium and 4μg/kg of fentanyl were given before tracheal intubation. Anesthesia was maintained with inhalation of 2%-3% sevoflurane in the sevoflurane group or venous injection of 4-8mg/(kg·h) propofol in the propofol group. Fentanyl was intermittently injected and muscle relaxation was monitored by TOF-WatchSX during operation.  The following indexes were recorded: ① The times of the patients′ eyelash reflex loss and conscious recovery.② The times of onset, duration of function, average consumption of vecuronium, and adverse events of induction and extubation.  ③ The variation of heart rate and mean arterial pressure. Results     The time of eyelash reflex loss in the propofol group was shorter than that in the sevoflurane group（P＜0.01）. The onset time of vecuronium was shorter in the sevoflurane group than that in the propofol group（P＜0.01）. The function time of vecuronium in the sevoflurane group was longer than that in the propofol group（P＜0.01）. The consumption of vecuronium in the sevoflurane group was less than that in the propofol group（P＜0.01）. The time of opening eyes in response to voice was shorter in the sevoflurane group than that in the propofol group（P＜0.01）. The heart rate in the sevoflurane groupwas significantly lower（P＜0.05）and the mean arterial pressure in the propofol group was significantly lower（P＜0.05） before tracheal intubation, and there were no significant differences in variation of the heart rate and mean arterial pressure in the two groups during and at the end of operation. There was no irritating cough,breath holding,laryngospasm or respiratory inhibition during induction. There was no restlessness, nausea or vomiting during extubation. All patients in the two groups could correctly answer questions. Conclusion     Sevoflurane can enhance neuromuscular block of vecuronium and decrease the requirement of vecuronium .

Key words: Propofol； Sevoflurane； Vecuronium； Neuromuscular block