脑电双频指数指导吸入异氟烷对腹部手术老年病人麻醉恢复的影响

Titration of isoflurane using BIS index improves early recovery of elderly patients undergoing abdominal surgery

目的研究脑电双频指数(BIS)指导吸入异氟烷对腹部手术老年病人麻醉恢复的影响。方法65岁以上行腹部手术病人40例,ASAⅡ或Ⅲ级,随机分为对照组和BIS组,每组20例。对照组由同一麻醉科医生根据经验调节术中异氟烷的吸入浓度;BIS组术中维持BIS在50-60,手术结束前20min,BIS维持在60-70。记录诱导前、麻醉期间和拔管时的BIS、异氟烷挥发罐设定浓度和呼气末浓度;清醒时间、拔管时间和从手术结束至Aldrete麻醉恢复评分≥9的时间;简易智能状态检查(MMSE)评分。结果与对照组相比,BIS组术中异氟烷用量减少34%,麻醉、手术期间的BIS升高、呼气末异氟烷浓度降低,手术结束时呼气末异氟烷浓度降低,清醒时间、拔管时间和从手术结束至Aldrete麻醉恢复评分≥9的时间缩短;与麻醉前比较,BIS组术后1 h MMSE评分降低,对照组在术后1、2 h MMSE评分降低(P<0.05或0.01)。结论BIS指导吸入异氟烷能加快腹部手术老年病人麻醉恢复,并可减少术中异氟烷用量。

Objective To investigate the effect of BIS monitoring during isoflurane anesthesia on anesthesia recovery profile and isoflurane requirement in elderly patients undergoing elective intra-abdominal surgery.Methods Forty ASA Ⅱ or Ⅲ patients aged over 65yr undergoing elective intra-abdominal surgery were randomized to one of two groups （ n = 20 each ） ： BIS group and control group. Anesthesia was induced with fentanyl 1.5μg·kg^ -1 , propofol 1.5-2.0 mg· kg ^- 1 and recuronium 0.1 mg·kg^- 1 and maintained with inhalation of isoflurane （0.2%-2.0%）, 60% nitrous oxide and 02 and intermittent i.v. boluses of fentanyl. The patients were mechanically ventilated after endotracheal intubation. BIS sensor was applied to the forehead and connected to Aspect A-2000XP BIS monitor in both groups, but in control group the anesthesiologist was blinded to the BIS score. In BIS group isoflurane was titrated to keep BIS values between 50-60 during operation. The BIS value was increased to 60-70 at 20 min before the end of operation. In control group the depth of anesthesia was maintained based on the clinical experience of the anesthesiologist. If MAP was increased by 25 % of the baseline value or HR 〉 90 min, isoflurane concentration was increased or a bolus dose of fentanyl （25-50μg） was given i.v.. The BIS values before and during anesthesia and at extubation, emergence time, extubation time, the time between the end of operation and Aldrete anesthesia recovery score≥ 9, MMSE score and isoflurane consumption were recorded and compared between the two groups. Results The total amount of isoflurane consumed was 34 % lower in BIS group than in control group. The average BIS values were higher and end-tidal isoflurane concentration was lower in BIS group than in control group. The time from the end of surgery to eye-opening, to extubation and Aldrete score≥ 9 were significantly shorter in BIS group than in control group. The MMSE score was significantly decreased at 1 h after operation as compared to the baseline score before induction of anesthesia while in control group MMSE score was still significantly decreased at 2 h after operation. Conclusion Titration of isoflurane using BIS monitoring can reduce the dose of isoflurane during operation and contribute to faster recovery from anesthesia in elderly patients undergoing intra-abdominal surgery.