肥胖产妇剖宫产手术中蛛网膜下腔布比卡因运动阻滞的ED_(50)

A study on ED_(50)for motor block of intrathecal bupivacaine in obese parturients for Caesarean section

目的探讨以蛛网膜下腔布比卡因运动阻滞半数有效量(ED_(50))为脊麻给药剂量参考可否降低肥胖产妇剖宫产术中不良反应的发生率。方法 ASA Ⅰ或Ⅱ级择期剖宫产手术的肥胖产妇110例,体重指数(BMI)>30 kg/m^2,行腰硬联合麻醉,随机分为观察组和对照组.每组55例。观察组脊麻药含芬太尼20 μg,以 ED_(50)为脊麻给药剂量参考。用序贯法分别测定两组患者脊麻后0.5%布比卡因运动阻滞的 ED_(50),并观察两组产妇术中不良发应的发生率。结果两组患者 ED_(50)差异无统计学意义;观察组术中低血压、心律失常和恶心呕吐的发生率分别为10.0%、3.3%和6.7%,显著低于对照组的43.3%、20.0%和26.7%(P<0.05)。结论肥胖产妇剖宫产手术行腰硬联合麻醉时,以0.5%布比卡因蛛网膜下腔运动阻滞的 ED_(50)为脊麻给药剂量参考,可以降低术中不良反应的发生率。

Objective To investigate whether the referenced intrathecal dose of isobaric 0.5 bupivaeaine according to the median effective dose （ED50） for motor block might reduce the rates of complications in obese parturients for Caesarean section. Methods One hundred and ten ASA Ⅰ or Ⅱ parturients （BMI〉 30 kg/m^2） undergoing elective Cesarean section under combined spinal-epidural anesthesia （CSEA） were randomly allocated to experimental group and control group with 55 cases each. The referenced intrathecal dose of experimental group accorded to the ED50 ,in which fentanyl 20 μg was added. We determined the ED50 using up-down sequential technique and the rates of complications related to CSEA were recorded in two groups. Results There was no significant difference in the ED50 between two groups. The incidences of hypotension, arrhythmia, nausea and vomiting were significantly lower （10.0%, 3.3%, 6.7%） in experimental group than those in control group （43.3%, 20.0%, 26.7%） （P〈0.05）. Conclusion The referenced intrathecal dose of 0.5% bupivacaine according to the ED^o for motor block might reduce the rates of complications related to CSEA in obese parturients for Caesarean section.