Efficacy of different doses of sufentanil in minimum alveolar concentration of sevoflurane in patients undergoing bronchoscopy / 实用医学杂志

ABSTRACT

Objective To investigate the effects of different doses of sufentanil on the minimum alveolar concentration (MAC) of sevoflurane for sedation in patients undergoing bronchoscopy. Methods ASA physical status I orⅡpatients of both genders, aged 20 ~ 65, undergoing bronchoscopy under general anesthesia,were randomly divided into 4 groups (n=20 each):control group (group C) and different doses of sufentanil groups (Sl, S2 and S3 groups). Sufentanil 0.1, 0.2 and 0.3 μg/kg in 5 mL of normal saline was intravenously infused before induction of anesthesia in groups of SI S2 and S3 respectively. While 5 mL of the normal saline was given instead in the group C The patients were mechanically ventilated after insert laryngeal mask. Anesthesia was maintained with inhalation of sevoflurane. Each time the concentration of sevoflurane at end expiration increased/decreased in the next patient depending on the concentration of sevoflurane at end expiration with which the former had no cough. The ratio between the two consecutive concentrations was 1.1. The middle point between the positive response and negative response served as a crossover pair. After at least 7 independent crossover pairs were observed in each group. The MAC and 95%confidence interval of sevoflurane were calculated. The time of anesthesia induction and analepsis was recorded. Results The MAC (95%CI) of sevoflurane was 3.0%(2.8%~3.3%), 2.3%(2.1%~2.5%), 1.9%(1.6% ~ 2.2%) and 1.6% (1.3% ~ 1.9%) in groups of C, S1, S2 and S3 respectively. The MAC of sevoflurane was significantly lower in groups of S1, S2, S3 than in the group C, and in groups S3 than in the group S1 (P<0.05). The time of anesthesia induction was significantly shorter in groups of S2, S3 than in the group C and significantly longer in groups S3 than in the group C. Conclusion Sufentanil of 0.1, 0.2, 0.3 μg/kg can significantly decrease the MAC of sevoflurane in patients undergoing bronchoscopy in a dose-dependent manner.