硬膜外阻滞与全身麻醉下老年患者乳酸钠林格氏液容量动力学的比较

Volume kinetics of lactated Ringer＇s solution during induction of epidural versus general anesthesia in eld- erly patients

目的比较乳酸钠林格氏液用于硬膜外阻滞和全身麻醉下老年患者的容量动力学。方法择期手术的老年患者40例，性别不限，年龄66—86岁，体重45～86kg，ASA分级Ⅰ或Ⅱ级。硬膜外阻滞组（EA组，n=20）于硬膜外注射局麻药前10rain开始恒速静脉输注乳酸钠林格氏液，全身麻醉组（GA组，n=20）于麻醉诱导前20min开始恒速静脉输注乳酸钠林格氏液，乳酸钠林格氏液的容量为1000ml，输注时间60min。每隔5min采集动脉血样，检测血红蛋白浓度，采用物质平衡规律动态分析公式计算血浆稀释度、单位体重血容量增加量及血容量扩张效率。结果与EA组比较，GA组输注乳酸钠林格氏液30—60min时血浆稀释度、单位体重血容量增加量及血容量扩张效率升高（P〈0．05或0．01）。结论与硬膜外阻滞相比，全身麻醉下老年患者乳酸钠林格氏液的血容量扩张效率更强。

Objective To compare the volume kinetics of lactated Ringer＇ s solution during induction of general and epidural anesthesia in elderly patients. Methods Forty ASA Ⅰ or Ⅱ patients, aged 66-86 yr, weighing 45-86 kg, undergoing elective surgery, were studied. In epidural anesthesia group （n = 20）, lactated Ringer＇s solution was infused intravenously starting from 10 min before epidul＇al anesthesia was performed with local anesthetics. In general anesthesia group （ n = 20）, lactated Ringer＇ s solution 1000 ml was infused intravenously over 60 min starting from 20 min before induction of anesthesia. Arterial blood samples were obtained every 5 rain for measurement of hemoglobin concentrations. The plasma dilution, volume increase, and volume expansion effi- cacy were calculated. Results The plasma dilution, volume increase and volume expansion were significantly higher at 30-60 min of lactated Ringer＇s solution infusion in general anesthesia group than in epidural anesthesia group （ P 〈 0.05 or 0.01 ）. Conclusion The volume expansion of lactated Ringer＇ s solution is greater in elderly patients during induction of general anesthesia than that during induction of epidural anesthesia.