经皮穴位电刺激对全麻髋关节置换术老年患者控制性降压期间脑氧代谢的影响

目的:观察经皮穴位电刺激对老年患者行控制性降压期间的脑保护作用。方法:40例美国麻醉医师协会分级Ⅰ或Ⅱ级实施全髋关节置换手术的65岁以上老年患者,随机均分为对照组和复合针麻组,两组患者均采用控制性降压以减少术中出血。其中复合针麻组患者在麻醉诱导前给予双侧鱼腰、风池30min经皮穴位电刺激,并持续至手术结束,刺激参数:采用2Hz/100Hz的疏密波,电流强度8~12mA。对照组采用假穴位经皮穴位电刺激(与复合针麻组相同的穴位向内旁开1寸)。分别在降压开始前(T0),降压至目标平均动脉压(MAP)后20min(T1)、40min(T2)和停止降压后20min(T3),抽取颈内静脉球部和桡动脉血液进行血气分析,记录各时间点MAP、心率(HR)、动脉血氧含量(CaO2)、静脉血氧含量(CjvO2)、脑动-静脉血氧含量差(Da-jvO2)、脑氧摄取率(CERO2)。结果:与T0时比较,两组各时间点MAP、HR、CaO2的差异无统计学意义(P0.05),T1、T2和T3时CjvO2升高,Da-jvO2和CERO2降低(均P0.05);与对照组比较,复合针麻组T2、T3时CjvO2升高,T2时Da-jvO2和CERO2降低(均P0.05)。结论:经皮穴位电刺激可降低全麻髋关节置换术老年患者控制性降压期间脑氧代谢率,具有脑保护作用。

Effects of Transcutaneous Electrical Acupoint Stimulation Combined with General Anesthesia on Cerebral Oxygen Metabolism in Elderly Hip Replacement Patients during Controlled Hypotension

Objective To observe the protective effect of transcutaneous electrical acupoint stimulation(TEAS)on cerebral tissue in elderly hip replacement operation patients during general anesthesia under controlled hypotension.MethodsForty hip replacement operation patients were randomly divided into general anesthesia(GA)control group and TEAS+GA group(n=20in each group).Patients of the two groups during operation were treated with controlled hypotension for reducing blood loss.TEAS(2Hz/100Hz,8-12mA)was applied to bilateral Yuyao(EX-HN 4)and Fengchi(GB 20)and began 30min before GA.General anesthesia was performed by intravenous injection of Midazolam,Diprivan,Fentanyl and Cis-atracurium,sevoflurane-inhaling,Remifentanil,etc.,and the patient's mean arterial pressure was maintained to be about 70% of the normal level(controlled hypotension)by using venous administration of Remifentanil about 10min after the operation.GEM Premier 3000blood gas analyzer was used to analyze levels of the arterial oxygen(CaO2),internal jugular venous oxygen(CjvO2),arterio-venous oxygen content difference(Da-jvO2)and cerebral oxygen(CERO2)uptake rates of blood samples before controlled hypotension(T0),20min after controlled hypotension(T1),40min after controlled hypotension(T2)and 20min after the end of controlled hypotension(T3).Results Self-comparison of each group showed that in comparison with pre-controlled hypotension,CjvO2levels at the time-points of T1,T2and T3 were significantly increased in both GA control and TEAS+GA groups(P<0.05),while Da-jvO2and CERO2 uptake rate levels at the time-points of T1,T2 and T3in these two groups were significantly decreased(P<0.05).Comparison between two groups showed that CjvO2levels at the time-points of T2and T3were significantly higher in the TEAS+GA group than in the GA control group(P<0.05),while Da-jvO2and CERO2uptake rate levels at the time-point of T2were obviously lower in the TEAS+GA group than in the GA control group(P<0.05),suggesting a reduction of cerebral oxygen consumption after TEAS.No significant differences were found between these two groups in blood CjvO2,Da-jvO2and CERO2uptake rate levels at the time-points of T0and T1(P>0.05).Conclusion TEAS can reduce cerebral oxygen uptake rate in elderly patients undergoing hip replacement during controlled hypotension,suggesting aprotective effect of TEAS on patient's cerebral tissue.