持续静脉注射咪达唑仑对丙泊酚效应室靶浓度的影响

目的:观察相同麻醉镇静深度时不同剂量咪达唑仑持续静脉注射对丙泊酚效应室靶浓度的影响,选择这2种药物间满意的复合方案。方法:60例ASA 1-2级妇科腹腔镜手术病人,随机分为3组(n= 20)。P组:以3 mg·L-1的初始靶浓度靶控输注丙泊酚后静脉注射芬太尼2-3μg·kg-1,维库溴胺0．12 mg·kg-1并调整丙泊酚靶浓度至脑电双频指数(BIS)低于50时气管插管,呼吸机控制呼吸;M1组和M2组:在P组基础上,靶控输注丙泊酚前静脉注射咪达唑仑0．05 mg·kg-1,然后分别以0．04 mg·kg-1·h-1和0．08 mg·kg-1·h-1的速度持续静脉泵入咪达唑仑。术中调整丙泊酚靶浓度维持BIS于45-55之间。记录麻醉苏醒时间及醒后镇静／觉醒(OAA／S)评分。每隔5 min记录丙泊酚效应室靶浓度,次日随访病人不良反应情况。结果:随咪达唑仑剂量增加麻醉维持中的丙泊酚效应室靶浓度降低,组间差异显著(P<0．05),苏醒时间略延长,但组间无显著差异(P>0．05)。醒后OAA／S评分P组明显高于M1和M2组(P<0．05);M1及M2组术后嗜睡者较P组增多(P<0．05)。术后并发症组间无显著差异(P>0．05)。结论:维持相同麻醉镇静深度时,丙泊酚效应部位靶浓度随咪达唑仑剂量的增加呈剂量依赖性降低。在以丙泊酚靶控输注为基础的静脉全麻妇科腹腔镜手术中,复合0．08 mg·kg-1·h-1的咪达唑仑持续静脉注射为宜。

Effects of continuous midazolam intravenous infusion on effective chamber target concentration of propofol

AIM:To study the influence of continuous intravenous infusion of different doses of midazo-lam on the effective chamber target concentration of propofol required to maintain the same depth of sedation and to select the optimal combination of these two anesthetics. METHODS: Sixty female patients with ASA physical status 1 - 2 scheduled for larparoscopic gynecologic surgery were randomly divided into three groups (n = 20 each): propofol group (group P), midazolamⅠgroup (group M,), and midazolamⅡgroup (group M2). For all patients, the induction concentration of propofol was 3 mg·L-1 followed by administration of fentanyl (2-3μg·kg-1) and vecuronium bromide (0.12 mg·kg-1). For the latter two groups, before propofol induction, midazolam (0.05 mg·kg-1) was intravenously injected followed by two doses of midazolam (0.04 mg·kg-1·h-1 in group M1, 0.08 mg·kg-1·h-1 in group M2). Propofol concentration was initially adjusted to keep the BIS value below 50. After trachea intubation, the patients were under mechanical ventilation and propofol concentration was adjusted to maintain the BIS value between 45 and 55 during operation. The effective propofol concentration was recorded every 5 min, together with the time of recovering consciousness and OAA/S scores for each group, including the adverse reactions on the following day. RESULTS: Along with the increase of the midazolam doses, the required effective propofol concentration showed significant decrease (P < 0.05). Although the time periods of recovering consciousness from anesthesia increased, there were no significant differences among the three groups (P > 0.05). OAA/S scores were higher in the group P than those in groups M1 and M2 (P < 0.05) , and the postoperative sleepiness was more common in the midazolam groups (P < 0.05). There was no significant difference in the occurrence of the adverse reactions among the three groups (P > 0.05). CONCLUSION: There was a dose-dependent decrease in the effective propofol concentration required to maintain the same depth of sedation with increase of midazolam dosage. For propofol-based anesthesia performed in larparoscopic gynecologic surgery, continuous intravenous infusion of midazolam at the dose of 0.08 mg·kg-1·h-1 is the optimal combination of these two anesthetics.