不同麻醉方法对心率变异性的影响

通过评价心率变异性（ＨＲＶ）的改变，研究不同麻醉方法对自主神经反射功能的影响。４０例成年患者分四组：（１）０．９５％异氟醚；（２）芬太尼 ５μｕｇ／ｋｇ十硫喷妥钠 ４ｍｇ／ｋｇ；（３）上胸段硬膜外阻滞；（４）腰段硬膜外阻滞。各组于麻醉前后分别采得连续５分钟的心电信号，由计算机程序进行ＨＲＶ谱分析。结果显示，０． ９５％异氟醚可降低 ＨＲＶ低频分量减少 ９１． ７％（Ｐ＜Ｏ． ０００１），中频减少 ８４． ４％（Ｐ＜０． ０００１），高频减少８２％（Ｐ＝０．００１）；芬太尼５μｇ／ｋｇ组仅中频和高频分别减少６３．４％（Ｐ＝０．０１１５）和６５．４％（Ｐ＝０．０１１４）；上胸段硬膜外阻滞后低频峰和中频峰分别减少６６％（Ｐ＝０ ．０２）和６５％（ｐ＝０．００３）；腰段硬膜外阻滞后，ＨＲＶ未受阻抑。结论：麻醉可影响自主神经反射所介导的ＨＲＶ。//

Effects of different anesthetic techniques on heart rate variability

Fourly adult healthy patients were separately anesthetlzed with (1 )0. 95% isoflurane; (2) fentanyl 5g/kg and thiopentone 4 mg/kg; (3) upper thoracic epidural blockage and (4 ) lumbar epidural blockage,Continuous 5 min ECG were recorded before and a fier anesthesia with spectral analysis of heart rate varlability (HRV) performed by computer program. For power spectral measurement,three frequency band of HRV were evaluated and the effects of each anesthesia were compared. HRV reduced markedly in patients using 0. 95 % isoflurane. with decreases of frequency by 91. 7% (low frequency ), 84. 4% (mid frequency ). and 82% (high-frequency) respectively. In patients after administration of fentanyl 5g/kg, mid and high-frequency components declined 63. 4 % and 65. 4 %. Upper thoracic epidural block restrained the mid and low frequency components by 66 % and 65 % respectively, Following lumbar epidural block the pattern of HRV components did not change. It is concluded that different anesthesia techniques may have significant different effects on autonomic reflexes as presented by HRV.