小剂量异丙酚对不同温度下冠状动脉搭桥术中麻醉深度的影响

目的观察小剂量异丙酚在浅低温冠状动脉搭桥体外循环期间麻醉深度的变化。方法选择择期行冠状动脉搭桥的患者40例，随机分成浅低温组（I组）和中低温组（Ⅱ组）各20例。患者入室后行心电、有创血压、Narcotrend监测。两组患者在锯胸骨前间断推注芬太尼30～50μg/kg，在体外循环（CPB）期间并丙酚0．2mg／（kg·h）静脉持续输注。I组采用浅低温，鼻温控制在33—35℃；1I组采用中低温，鼻温控制在29～31℃，维持平均动脉压（MAP）40～60mmHg（1mEHg=0．133kPa），控制血细胞比容（Hct）在30％～35％之间。记录CPB前5min（To）、CPB开始后5min（T1）、CPB开始后30min（T2）、停CPB时（T3）、停CPB后15min（T4）共5个时间点的Narcotrend NI指数、鼻咽温度（T）、MAP和Hct值。结果组内比较：I组患者的NI、T、Hct和MAP在各时点间比较差异无统计学意义（P〉0．05）。Ⅱ组患者，NI在T0和T4时要高于T1、T2和T3（P〈0．05），在T2时低于T0、T1、T3和T4（P〈0．05）。组间比较：T2时点的NI在I组比Ⅱ组高（P〈0．05）。两组患者T、Hct和MAP在各时间点间的比较差异无统计学意义（P〉0．05）。结论与中低温相比，浅低温冠状动脉搭桥期间的麻醉深度变化不大。

Effect of low - dose propofol on the depth of anesthesia during coronary artery bypass graftingwith different temperature

Objective To investigate the effects of low close propofol on the depth of anesthesia during coronary artery bypass grafting with mild hypothermia. Methods Forty patients scheduled for coro- nary artery bypass grafting were randomly divided into two groups ： group I （ mild hypothermia, n = 20） and group Ⅱ （moderate hypothermia, n = 20）. ECG, invasive blood pressure, temperature of nasal cavity and Narcotrend were continuously monitored during the anesthesia. All the patients received fentanyl （interval infusion 30 -50 μg/kg） before sawing sternum, and propofol maintenance infusion, 0.2 mg/（kg·h） during circulation pulmonary bypass （CPB）. The lowest nasopharyneal temperature were 33 -35 ℃ （mild hypothermia） in group I and 29 -31 ~C （moderate hypothermia） in group 1I during circulation pulmonary bypass. In the same time, mean artery pressure was kept 40 -60 mm Hg（1 mm Hg =0. 133 kPa）,and Hct was 30% -35%. Narcotrend NI, nasopharyneal temperature, mean artery pressure and Hct were recorded at the following five time points ： 5 rain before CPB （ To ）, 5 rain into CPB （ T1 ）, 30 rain into CPB （ T2 ）, im- mediately stopping CPB and 15 rain after CPB. Results No significant difference was found in NT, T, Hct and MAP in group I. NT was increased at To and T4 as compared with the baseline values at T1 ,T2 and T3 in group 1I. NT at T2 was lower than at To ,T1 ,T3 and T4 in group lI. No significant difference was found in T, Hct and MAP in group I1. Conclusions Compared with that in moderate hypothermia, the depth of anesthesia did not significantly change in mild hypothermia during coronary artery bypass grafting