胸段硬膜外阻滞对急性心肌缺血再灌注损伤影响的实验研究

Protective effects of TEA againist myocardial ischemiareperfusion injury.

目的 探讨胸段硬膜外阻滞（TEA）对缺血再灌注损伤心肌的保护作用。方法 将22只犬随机分为生理盐水对照组（NS组，7只）、布比卡因组（BP组，8只）及罗哌卡因组（RP组，7只）。麻醉后行T5～T6硬膜外穿刺，NS组、BP组及RP组分别于硬膜外腔注入生理盐水、布比卡因、罗哌卡因各12ml;开胸阻断左冠状动脉前降支（LAD）40min后再灌注320min。实验过程中监测平均动脉压（MAP）和心率（HR），于硬膜外腔注药前，阻断时及开放后60、120min时测血清MDA与SOD水平。结果 三组HR在实验过程中无显著变化，组间亦无差异；MAP在注药前较术前均明显升高（P〈0．05），而在以后各时点，NS组较术前无显著差异，而BP组、RP组则明显下降（P〈0．01）;三组间术前、注药前的MAP无显著差异，而阻断时、阻断末及开放60、120min时，RP组与BP组MAP明显低于NS组（P〈0.05、0．01），RP组与BP组间无差异。三组阻断末MDA与SOD较注药前无显著变化；开放60、120min时，NS组MDA显著增高，SOD明显下降（P〈0．05），而BP组与RP组MDA与SOD无明显变化。三组间各时点MDA无显著差异，注药前、阻断末的SOD亦无显著差异。开放期BP组、RP组SOD明显高于NS组（P〈0．01、〈0．05），RP组显著高于BP组（P〈0．05）。结论TEA对缺血再灌注损伤心肌有保护作用；罗哌卡因的心肌保护效果优于布比卡因。

Objective： To explore the protective effects of thoracic epidural anesthesia （TEA） aganist myocardial ischemia-reperfusion injury. Methods; 22 canines （14 - 22kg） were divided randomly into NS group （n = 7）, BP group （n = 8） and RP group （n = 7）. Conducted epidural puncturing at T5 - T6 after general anesthesia, injected normal saline , Bupivacaine, Ropivacaine into the epidural space respectively 12 ml for NS group, BP group, RP group. All the dogs were subjected to LAD occlusions for 40min and reperfused for 320min. MAP and HR were measured continually; Before epidural injection, at start occlusion and after opening 60 min, 120min after opening, MDA and SOD were measured respectively. Results： There were no significant change and difference of HR in 3 groups; Before epidural injection,MAP of 3 groups increased significantly than that hefore surgery （P〈 0. 05）. At latter time points, MAP had no significant diference in NS group and decreased significantly in other two groups （P〈0. 01）. At occlusion, end occlusion, 60 min, 120 min after opening, MAP in BP group and RP group were significantly lower than that in NS group （P〈0. 05, 〈0.01）. At end occlusion, MDA and SOD of 3 groups had no significant diference with that hefore epidural injection. At 60min and 120min after opening, MDA increased significantly and SOD decreased significantly in AS group （P〈 0. 05）. Conclusionz TEA can protect cardiac muscle aganist ischemia-reperfusion injury, and the protective effects of Ropivacaine is hetter than that of Bupivacaine.