老年人不同节段硬膜外阻滞的自主神经功能差异

AUTONOMIC NERVOUS SYSTEM FUNCTIONS UNDER DIFFERENT LEVEL EPIDURAL ANESTHESIA IN THE ELDERLY

目的在老年病人中比较下胸段和腰段硬膜外阻滞对自主神经功能的影响。方法选择在腰段硬膜外阻滞下行下腹部手术(A组)和下胸段硬膜外下行上腹部手术(B组)的老年病人各15名。监测心率变异性,低频(LF:0.03Hz-0.15Hz)反应副交感和交感活性,高频(HF:0.15Hz-0.4Hz)反映副交感活性。结果A组术前的LF为494.60±241.87,阻滞后下降到308.05±148.05(P<0.01),切皮时上升至392.43±205.23,而B组由526.90±397.77降至124.17±92.33和158.20±129.43(两者P<0.01)。LF/HF在A组由3.39±1.86下降至2.46±0.85和2.58±0.98(P<0.01),B组3.10±1.90下降至1.30±0.60和1.47±0.56(两者P<0.01)。HF和TP变化没有统计学意义。在B组中,反映交感活性的LF、LF/HF有统计学意义的抑制,同时心率明显下降(80.70±9.20降至68.40±7.40)。结论与腰段硬膜外相比,下胸段硬膜外阻滞在老年病人中更容易导致交感神经抑制,麻醉和术中注意提高交感神经活性。

Objective The purpose of this study was to evalu ate autonomic nervous system activity during low thoracic and lumbar epidural anaesthesia in t he elderly.Methods 15senile patients undergoing lower abdominal surgery with lumbar epidural anesthesia(Group A),and other 15senile patients underg oing upper abdominal surgery under l ow thoracic epidural anaesthesia(Group B )were selected.The autonomic nervou s system activity was measured by hea rt rate variability with power spectral analysis.Low frequency component (LF:0.03Hz ～0.15Hz )indicated both sympathetic and para sympathetic activity while a high frequency component (HF:0.15Hz ～0.4Hz )reflected parasympathetic activity.Results LF,LF /HF that indicated sympathetic were inhibited significantly in Group B with HR decreased after epidural block.LF:Fr om 526.90±397.77to 124.17±92.33(after epidural block,P<0.01)and 158.20±129.43(while making incision,P<0.01).LF /HF:From 3.10±1.90to 1.30±0.60a nd 1.47±0.56(both P<0.01).Conclusions Compared with lumbar epidural anesthesia,low thoracic e pidural anesthesia blocked sympath etic tensions more effectively in th e elderly.[