关键词: 麻醉药, 吸入, 右美托咪定, 七氟醚, 吸入麻醉, 浓度, 苏醒

Abstract: Abstract： Objective To investigate the effects of dexmedetomidine on the end- tidal concentration of sevoflurane during recovery from breast cancer surgery under general anaesthesia. Methods A total of 120 patients undergoing unilateral breast cancer radical operation were randomly divided into four groups: group C (infusion of saline, n=30), group D0.5 [infusion of dexmedetomidine 0.5 μg/(kg·h) during operation, n=30], group D0.6 [dexmedetomidine 0.6 μg/(kg·h), n=30] and group D0.7 [dexmedetomidine 0.7 μg/(kg · h), n=30]. The end- tidal concentrations of sevoflurane during surgery and postoperation were observed. The end- tidal concentration of sevoflurane on palinesthesia was recorded. The time from stopping administration of anesthetic drug to palinesthesia and the operation time were recorded. The palinesthesia of patients from general anaesthesia and the degree of emergence agitation of the patient were measured using Riker’ s sedation- agitation scale. The operation time, anesthesia time, intraoperative remifentanil dosage, intraoperative auditory evoked potential index (AAI), sevoflurane inhalation concentration and the corresponding time were recorded. Results There were no significant differences in clinical data, remifentanil dosage, operation time and AAI between four groups. The anesthesia time was longer in group D0.7 than that in the other three groups (P < 0.05). Compared to group C, the end-tidal concentration of sevoflurane during surgery, postoperation and palinesthesia were lower and the time of palinesthesia was delayed in groups D0.5, D0.6 and D0.7 (P < 0.05). And the time of palinesthesia was delayed in group D0.7 than that of group D0.5 and group D0.6. Compared with group C, the ratio of Riker’ s sedation-agitation scale >7 was lower in groups D0.5,D0.6 and D0.7 (P < 0.05). The ratio of Riker’ s sedation-agitation scale >4 was significantly higher in group D0.6 and group D0.7 than that in group C and group D0.5, but the ratio of score>6 was lower (P < 0.05). The ratio of score>3 was higher in group D0.7 than that of other three groups (P < 0.05). Intraoperative cardiac tachycardia was found in group D and group D (4 cases, 13% and 8 cases, 7%). Conclusion Sevoflurane inhalation anesthesia and intravenous infusion of dexmedetomidine 0.6 μg/(kg·h) can effectively reduce intraoperative sevoflurane dosage, the end- tidal concentration of sevoflurane during recovery, and the occurrence of agitation in patients undergoing general anesthesia.

Key words: anesthetics, inhalation, Dexmedetomidine, sevoflurane, inhalation anesthesia, concentration, palinesthesia