硬膜外麻醉对心率变异性的影响

The influence of epidural anesthesia on heart rate variability

目的 :观察硬膜外麻醉对心率变异性 (HRV)的影响。方法 :2 5例ASAⅠ～Ⅱ级择期手术患者 ,以硬膜外穿刺部位的高低分为A、B两组 :A组 1 5例为中胸段硬膜外麻醉组 ;B组 1 0例为腰段硬膜外麻醉组。分别测定硬膜外麻醉前后心率变异性的功率谱及心率、血压变化。结果 :中胸段硬膜外麻醉后低频 (LF)、平均动脉压 (MAP)均显著下降 (P <0 .0 5 ) ,LF值与血压的变化之间存在正相关。腰段硬膜外麻醉对HRV未见明显影响。腰段麻醉 1 0min后LF、高频 (HF)、总功率 (TF)、MAP均高于中胸段麻醉 (P <0 .0 5～P <0 .0 1 )。结论 :中胸段硬膜外麻醉可影响心率变异性 ,使反映交感神经张力的LF值明显下降 。

Objective:To observe the influence of epidural anesthesia on heart rate variability(HRV).Methods:Twenty five ASA ⅠtoⅡ patients scheduled for elective surgery under epidural anesthesia were included in this study.They were divided into two groups according to the segment of epidural block.Group A included 15 patients undergoing cholecystectomy or gastrectomy under epidural anesthesia on middle chest segment and group B included 10 patients undergoing orthopaedics operation on lower limbs under epidural anesthesia on lumbar segment.The Power spectrum of HRV,heart rate and blood pressure(BP) were observed before and after epidural anesthesia.Results:The value of low frequency(LF) and BP were markedly reduced 5,10,15 and 20 minutes after epidural anesthesia on middle chest segment( P <0.05).The value of LF correlated closely with BP( r =0.980 2, P <0.01).HRV changed little after epidural anesthesia on lumbar segment.Conclusions:The epidural anesthesia on middle chest segment has influence on HRV and reduces the value of LF reflecting the tension of the sympathetic nerve,which correlates with the level of epidural block.