Abstract: Objective To observe the effects of norepinephrine on preventing hypotension during cesarean section under combined spinal?epidural anesthesia（CSEA）for mothers and infants. Methods This was a prospective study. Sixty patients undergoing cesarean section under CSEA were block divided into three groups，Group A，Group B and Group C，20 cases in each group. Twenty minutes before initiation of combined spinal and epidural anaesthesia ， patients were randomized to receive norepinephrine 0.05 μg·kg?1·min?1 in group A，norepinephrine 0.1 μg·kg?1·min?1 in group B，and saline 0.1 μg·kg?1· min?1 in group C，respectively. All the groups of patients were injected with 0.5% ropivacaine 3 mL at the L3 4 space for spinal anesthesia. Mean arterial pressure（MAP）and heart rate（HR）in the three groups of patients were observed and recorded at the following eight time points：before anesthesia（T1），spinal injection of the anesthetic （T2），5 min after spinal anesthesia （T3），10 min after spinal anesthesia （T4），20 min after spinal anesthesia（T5），postoperation（T6），postoperative 8 h（T7）and postoperative 24 h（T8）. The neonatal Apgar score，blood gas analysis，maternal adverse reactions in the three groups were observed. Results There was no statistical difference in MAP and HR among the three groups at T1， and no statistical difference in MAP and HR between group A and group B at each time point（P>0.05）. Compared with T1，MAP in group C at T3，T4 and T5 decreased significantly，HR in group C at T4 decreased significantly（P<0.05）. At T3，T4 and T5，MAP in group C was significantly decreased than that in group A and group B（P<0.05）. The levels of PaO2，PaCO2 and PH in umbilical cord blood of the three groups were not statistically different（P>0.05）. The incidences of nausea，vomiting and headache in group A and group B were significantly lower than those in group C（P<0.05）. The Apgar scores at 1 min and 5 min after born in the three groups were not significantly different（P>0.05）. Conclusion The outcomes showed preanesthesia 0.05 μg/kg·min norepinephrine was effective in preventing hypotension in cesarean section under combined spinal epidural anesthesia，and has little impact on mothers and infants，thus was safe.

Key words: hypotension, norepinephrine, combined spinal epidural anesthesia, cesarean section

摘要： 目的 研究去甲肾上腺素预防腰硬联合麻醉下剖宫产低血压对母婴的影响。方法 采用前瞻性研究方法，选择腰硬联合麻醉下择期行剖宫产的患者60 例，按区组分A、B、C 三组，每组20 例。在麻醉开始前20 min 分别按照以下速度恒速泵入药品，A 组去甲肾上腺素0.05 μg/kg·min，B 组去甲肾上腺素0.1 μg/kg·min，C 组生理盐水0.1 μg/kg·min，均持续20 分钟停止。三组患者均在 L34 间隙注入 0.5% 罗哌卡因 3 mL 行腰麻。观察记录三组患者以下时间点的平均动脉压（MAP）及心率（HR）变化，麻醉前（T1）、腰麻给药（T2）、给药后5 min（T3）、给药后10 min（T4）、给药后20 min（T5）和术毕（T6）术后8 h（T7）和术后24 h（T8），观察三组新生儿Apgar 评分、血气分析、产妇不良反应发生情况。结果 三组患者T1 时 MAP 及 HR 差异无统计学意义，A、B 两组患者在各时间点 MAP 及 HR 差异无统计学意义（P>0.05）。与 T1 时比较，C 组患者T3、T4、T5 时 MAP 明显降低，T4 时 HR 明显降低，差异有统计学意义（P<0.05）。T3、T4、T5 时C 组患者 MAP 明显低于A 组和B 组，差异有统计学意义（P<0.05）。三组胎儿脐血 PaO2、PaCO2、PH 水平对比均不明显，差异均无统计学意义（P>0.05）。A、B 组患者恶心、呕吐、头痛发生率均显著低于 C 组，差异均有统计学意义（P<0.05）。三组新生儿 1 min、5 min 的 Apgar 评分比较不明显，差异均无统计学意义（P>0.05）。结论 麻醉前去甲肾上腺素 0.05 μg/kg·min 可有效预防腰硬联合麻醉下剖宫产低血压，且对母婴的影响较小，安全性较佳。

关键词: 低血压, 去甲肾上腺素, 剖宫产, 腰硬联合麻醉