甲泼尼龙对体外循环后肺血管内皮依赖性舒张功能的影响

目的：探讨麻醉诱导后注射10mg／kg甲泼尼龙对低温体外循环（CPB）前后肺血管内皮依赖性舒张功能的影响。方法：选择择期进行瓣膜替换或修复术的患者32例，随机分为两组，每组16例，对照组在麻醉诱导后注射10ml生理盐水，实验组在麻醉诱导后注射甲泼尼龙10mg／kg，稀释至10ml。麻醉方法、CPB方法和术后管理标准化。常规进行血流动力学监测和呼吸监测，分别在麻醉诱导后和手术结束时进行乙酰胆碱（Ach）试验，记录注射Ach前后肺血管阻力指数（PVRI）的变化，观察手术前后肺血管内皮依赖性舒张能力的改变。结果：共有31例进入统计分析，对照组15例，甲泼尼龙组16例。两组患者术前一般情况、CPB时间、主动脉阻断时间和术中失血量无明显差异。术前两组基础的PVRI值无明显差异，两组肺循环对注射Ach的反应相似，注射Ach后PVRI的下降幅度在两组间无统计学差异；手术后，实验组比对照组对Ach有更好的反应（P〈0．01）；手术前后实验组注射Ach后PVRI下降的幅度无明显变化（术后19．8％w．术前23．6％，P〉0.05），而手术后对照组肺血管床对Ach的反应明显减弱，PVRI下降的幅度与术前相比有明显差异（7．9％ vs．21．5％，P〈0．01）。结论：麻醉诱导后给予10mg／kg甲泼尼龙能保护内皮功能，改善肺血管内皮依赖性舒张功能。

Effects of Methylprednisolone on Pulmonary Endothelial Function after Hypothermic Cardiopulmonary Bypass

Objective:To investigate whether 10mg/kg Methylprednisolone (MP) could effectively protect pulmonary endothe-lial functions and improve endothelium-dependent relaxation after hypothermic cardiopulmonary bypass (CPB). Methods thirty-two adult patients undergoing elective valves repair or replacement with moderate hypothermic cardiopulmonary bypass were included in this study. Patients of the treatment group (Group MP) received 10mg/kg MP after induction of anesthesia, and patients of the control group (Group NS) were administered 10ml normal saline at the same time. Anesthetic managements, extracorporeal circulation techniques and postoperative treatments were standardized according to our clinical routines. Various hemodynamic and pulmonary measurements were recorded. Responses of pulmonary vascular to acetylcholine (Ach) were measured after induction of anesthesia and at the end of surgery, respectively. The reactivity was calculated from PVRI measured before the start of an infusion of Ach and PVRI measured after the infusion. Results:One patient in Group NS was omitted from statistical analysis because of reoperation 2 hours after surgery, so results were presented for 15 patients in Group NS and 16 patients in Group MP. There were no differences between groups regarding demographic characteristics, cross-clamp times, duration of CPB and intraoperative blood loss. Baseline PVRI didn't differ in two groups. PVRI decreased similarly during infusion of Ach in both groups before surgery. After surgery and CPB there was a better reactivity in Group MP than in Group NS (P<0.01). Conclusion:Injecting lOmg/kg MP after the induction of anesthesia could effectively protect pulmonary endothelial function and improve endothelium-dependent relaxation after hypothermic cardiopulmonary bypass.