急性主动脉夹层术体外循环期间50%氙气静态膨肺对氧自由基的影响

Effects of pulmonary static inflation with 50% Xenon during cardiopulmonary bypass on reactive oxygen species in acute Stanford-A aortic dissection patients undergoing emergency surgery

目的:急性主动脉夹层(AAD)手术围术期病死率和并发症均明显高于其它心脏手术。缺血再灌注损伤导致的活性氧增加和抗氧化剂减少与主动脉夹层手术围术期转归密切相关。本研究通过Stanford A型夹层手术体外循环(CPB)期间给予50%氙气静态膨肺,观察围术期氧自由基变化情况并初步探索氙气作用机制。方法:发病14d以内的急性Stanford A型夹层患者并拟行急诊手术者共100例,根据CPB期间静态膨肺气体随机分两组:对照组50%氧气(5cm H_2O,1cm H_2O=0.098k Pa);氙气组50%氙气(气道压5cm H_2O)。记录患者围术期临床指标,并于诱导后(T_0),术后10min(T_1),术后6h(T_2)和术后24h(T_3)抽取静脉血测量氧自由基,包括丙二醛(MDA),;髓过氧化物酶(MPO),;总抗氧化能力(TAOC),;总超氧化物歧化酶(TSOD)。结果:两组患者术前的临床指标、围术期血流动力学及血生化学指标无明显差异,但氙气组术前控制血压例数多(64%vs.38%,P=0.009),Euro SCORE评分高(P=0.021)。住院病死率,术后机械通气时间两组之间无统计学意义。氙气组患者术前血清MDA及MPO水平达峰值,而对照组患者血清MDA及MPO水平在术后10min达峰值。两组MDA(P=0.000,0.050)及MPO(P=0.000,0.050)时间效应及时间-治疗交互作用明显。围术期TAOC及TSOD在两组中都有升高,时间效应明显(P=0.000,0.000),但时间-治疗交互作用不明显(P=0.757,0.134)。结论:急性Stanford A型主动脉夹层手术CPB期间50%氙气静态膨肺可以明显抑制术后氧自由基的释放,提高机体抗自由基损伤的能力。

Objective： Patients with Stanford A aortic dissection is at high risk of mortality and complication during perioperative period. In this study,we evaluate the effect of pulmonary static inflation with 50%Xenon during cardiopulmonary bypass on reactive oxygen species in acute Stanford A aortic dissection patients undergoing emergency surgery and investigate the possible mechanism of Xenon. Methods： 100 acute Stanford A aortic dissection（ onset ≤2 weeks） were randomly assigned to two groups according to Xenon or Oxygen,control group（ n = 50） ： pulmonary static inflation with 50% O_2（ 5cm H_2O）,Xenon group（ n = 50） ： pulmonary static inflation with 50% Xenon（ 5cm H_2O）. Blood samples were obtained at after anesthesia induction（ T_0）,10min（ T_1）,6 h（ T_2） and 24h（ T_3） after surgery to measure reactive oxygen species including methane dicar-boxylic aldehyde（ MDA）,myeloperoxidase（ MPO）,total anti oxidation capability（ TAOC）,total superoxide dismutase（ TSOD）. Results： There were no significant differences between the groups regarding patients＇ general clinical data and hemodynamics data. Mortality-adjusted postoperative mechanical ventilation duration and in-hospital mortality were not significant difference between two groups. In Xenon group,the serum level of MDA and MPO reached the peak at T_0,while at T_1 in control group. There was significant effect of time and treatment-time interaction for MDA（ P = 0. 000 and P = 0. 050,respectively） and MPO（ P = 0. 000 and P =0. 001,respectively）. Perioperative value of TAOC and TSOD increased in both groups during the study period,with a significant time effect（ P = 0. 000 and P = 0. 000,respectively）,but without significant difference of treatment-time interaction（ P = 0. 757 and P = 0. 134,respectively）. Conclusion： Pulmonary static inflation with 50% during CPB can decrease postoperative serum level of reactive oxygen species and increase the capability of body anti-oxidation of free radical.