日间与夜间靶控输注异丙酚镇静效果的比较

Comparison of the hypnotic effect of propofol administered by TCI during day-time and night-time

目的通过比较日间与夜间靶控输注异丙酚的镇静效果，探讨近日节律对异丙酚镇静效果的影响。方法局部或臂丛神经阻滞下行急诊手部小手术的男性患者65例，ASA分级Ⅰ或Ⅱ级，年龄18～55岁，BMI18．5～24．9kg／m2，根据患者手术时间分为日间组（07：01至19：oo）和夜间组（19：01至07：00）。行臂丛或局部神经阻滞，确认麻醉效果完善后开始靶控输注异丙酚，靶控输注过程采用阶梯给药方式，设定4个目标效应室靶控浓度，依次为0．8、1．2、2．0和4．0μg/ml。当异丙酚效应室浓度达到预设值后，维持5min，记录该浓度下的BIS值。靶控输注过程中每分钟进行1次警觉镇静评分（OAA／S评分），并记录OAA／S评分为2分（患者意识消失）时的BIS值和异丙酚效应室浓度。结果共有58例患者完成研究，其中日间组28例，夜间组30例。与日间组比较，夜间组BIS基础状态、异丙酚效应室浓度1．2和2．0μg／ml时BIS值降低（P〈0．05），异丙酚效应室浓度0．8和4．0μg／ml时BIS值差异无统计学意义（P〉0．05），OAA／S2分时异丙酚效应室浓度降低（P〈0．05）而BIS值差异无统计学意义（P〉0．05）。结论近日节律可影响患者异丙酚的镇静效果，表现为夜间镇静效果强于日间。

Objective To compare the hypnotic effect of propofol administered by target-controlled infusion （TCI） during day-time and night-time, in order to explore the effect of circadian rhythms on the sedative effect of propofol. Methods Sixty-five male ASA 1 or I1 patients aged 18-55 yr undergoing emergency minor hand surgery were divided into 2 gorups according to the time of the day when they received propofol TCI ： day-time group （from 7：01 to 19：00） and night-time group （from 19：01 to 7：00）. The pharmacokinetic parameters proposed by Schnider which predict effect-site concentration （Ce） were used. Four effect-site concentrations of propofol were set： 0.8, 1.2, 2.0 and 4.0 μg/ml. Ce was increased step by step and each Ce was maintained for 5 min. The level of sedation at each Ce was assessed by BIS and OAA/S scores. BIS value and Ce of propofol were recorded and compared between the 2 groups when the patients lost c9nsciousness （OAA/S score = 2）. Results There was 28 and 30 patients in day-time and nigher-time groups respectively. When Ce = 1.2 and 2.0 μg/ml, the BIS values were significantly lower in night-time group than in day-time group. There was no significant difference in BIS value between the 2 groups when Ce = 0.8 and 4.0 μg/ml. When the patients lost consciousness （OAA/S = 2）, the BIS value was comparable between the 2 groups, but Ce was significantly lower in night-time group than that in daytime group. Conclusion The hypnotic effect of propofol is greater during night-time than during day-time.