双侧胸椎旁神经阻滞对体外循环下冠状动脉旁路移植术中的心肌保护作用

目的探讨双侧胸椎旁神经阻滞对体外循环（ECC）下冠状动脉旁路移植术（CABG）心肌保护作用。方法择期CABG患者60例，随机分为两组双侧胸椎旁神经阻滞复合全麻组（P组）和单纯全麻组（G组），每组30例。P组患者麻醉诱导前经r13、T4间隙行双侧胸椎旁间隙穿刺置管，两侧分别注射试验剂量0．375％罗哌卡因5ml，5min后分别给予首次量0．375％罗哌卡因15ml。于ECC前、术毕、术后6h、24h和72h分别抽取静脉血，检测肌酸激酶同工酶（CKMB）、肌红蛋白（MYO）和心肌肌钙蛋白I（cTnI）的水平，观察两组血流动力学参数、心脏复跳情况、正性肌力药、ICU滞留时间等项目。结果两组MYO水平于术后72h恢复至正常，其余各时点两组术后CKMB、MYO和cTnI水平均高于ECC前（P〈0．05～P〈0．01）。除MYO的水平在术后72h差异无统计学意义，与G组比较，P组在其他各时点CKMB、MYO和cTnI的水平明显降低（P〈0．05）。P组患者术毕中心静脉压（CVP）、肺毛细血管楔压（PCWP）及体循环阻力指数（SVRI）低于G组（P〈0．05），心指数（CI）高于G组（P〈0．05）。P组患者术后24h多巴胺使用量、机械通气时间、ICU滞留时间明显低于G组（P〈0．05）。结论双侧胸椎旁阻滞对ECC下CABG术中具有心肌保护作用。

Myocardial protective effects of bilateral thoracic paravertebral block in patients undergoing extracorporeal circulation coronary artery bypass grafting

Objective To investigate myocardial protective effects of bilateral thoracic paravertebral block in patients undergo- ing extracorporeal circulation （ECC） coronary artery bypass grafting （CABG）. Methods Sixty patients scheduled for CABG were randomly divided into two groups （ n = 30 in each） ： bilateral thoracic paravertebral block combined with general anesthesia group （group P） and pure general anesthesia group （group G）. Bilateral thoracic paravertebral block and insertion epidural catheter were performed between T3 and T4 interspace prior to induction of anesthesia in group P. A test dose of 5 ml of 0.375 % ropivacaine was injected through the catheter in two sides; 5 min later a bolus dose of 15 ml of 0.375 % ropivacaine was injected. Blood samples were taken to determine the serum concentrations of CKMB, myoglobin （MYO） and cardiac troponin I （cTnI） before ECC, at the end of operation, postoperative 6 h, 24 h and 72 h respectively. Clinical data including hemodynamics, heart resuscitation condition, dosages of positive inotropic agent and time of ICU stay were recorded. Results The level of MYO recovered at postoperative 72 h in both groups. The levels of the cardiac biomarkers after operation in both groups were significantly higher than those before ECC （ P 〈 0.05 - P 〈 0.01 ） at the other time points. There was no significant difference in the level of MYO between two groups at postoperative 72 h; compared with group G, the levels of the cardiac biomarkers were significantly lower in group P （ P 〈 0.05 ） at the other time points. Compared with group G, central venous pressure （CVP）, systemic vascular resistance index （SVRI） and pulmonary capillary wedge pressure （PCWP） were significantly lower and cardiac index （CI） were significantly higher in group P （ P 〈0.05 ） at the end of operation. Dosages of positive inotropic agent, time of mechanical ventilation and residence time in ICU in group P were significantly reduced than those in group G （ P 〈 0.05）. Conclusion Bilateral thoracic paravertebral block shows effective myocardial protection in patients undergoing CABG with ECC.