老年人低位硬膜外麻醉围术期自主神经功能的变化

Changes of autonomic nerve system in senile patients with lower epidural anesthesia

目的 应用心率变异性 (HRV)分析仪监测评估低位硬膜外麻醉围术期自主神经的改变。方法 选择低位硬膜外麻醉下择期手术患者 2 0例 ,ASAⅠ～Ⅱ级 ,按年龄分为老年组和年轻组 ,每组 10例 ,观察术前 1d、麻醉完善后切皮前、切皮后 30min、术后 2h,1d ,3d,7d处时相点的心率 (HR)、平均动脉压 (MAP)以及HRV分析各成分变化。结果 围术期老年组HRV显示RMSSD(相邻RR间期差值的均方根 )、总频 (TP)、低频 (LF)、低频标化 (LFnorm)均呈显著性下降 ,同时伴有心率减慢、平均动脉压下降。年轻组TP和LF在麻醉完善后切皮前、术后 2h,1d下降显著 ,于术后 3d恢复 ,而HR和MAP在围术期无显著改变。两组间比较 ,老年组TP和LF在麻醉后各时相点均明显低于年轻组 (P <0 0 1)。老年组高频 (HF)及高频标化 (HFnorm)在麻醉给药后切皮前均无明显变化 ,但在术中和术后各时相点均下降 ,而年轻组仅切皮后 30min出现一过性下降。结论 HRV可较好地评估围术期机体自主神经变化 ;围术期麻醉和手术创伤均可使机体自主神经系统调节受损 ,尤其老年人受损程度大 ,恢复慢 ,术后 1周内仍不能完全恢复。

Objective To study the changes of autonomic nerve in patients with lower epidural anesthesia.Methods 20 patients(ASA Ⅰ～Ⅱ) being anesthesized with lower epidural nerve block were divided into 2 groups; the senile group ( n=10 ) and the young group ( n=10 ). Changes of heart rate (HR), mean arterial blood pressure (MAP) and heart rate variability (HRV) were observed and analyzed 1 d before operation, 15 min following epidural block, 30 min following incision, 2 h, 1 d, 3 d and 7 d after surgery. Results RMSSD(root of mean square R-R interval difference), TP(total power), LF(low frequency), LFnorm(low frequency normal) of HRV, HR and MAP all decreased significantly in the aged. TP and LF in the young group decreased significantly after epidural block, 2 h, 1d after surgery and then returned to the normal value 3 d after surgery, but perioperative HR and MAP did not chang significantly. TP and LF of all time point after lower epidural block in the senile group were significantly lower than that in the young group ( P<0.01 ). HF(high frequency) and HFnorm(high frequency normal) in the senile group decreased significantly except for the time points after epidural block and before incision, while HF and HFnorm in the young group decreased significantly only at 30 min following incision.Conclusion It is a good way to evaluate the changes of autonomic nerve system with HRV perioperatively. Both anesthesia and surgical trauma could be associated with the disturbances of perioperative autonomic nerve system of the patients, especially in the senile patients. Changes of autonomic nerve system may be one of the important risk factors of cardiovascular events during the perioperative period, especially in the senile patients.