瓣膜置换术中血浆胶体渗透压和乳酸的变化及对肺功能的影响

摘要

目的 探讨瓣膜置换术中血浆胶体渗透压(COP)的变化规律,以及对乳酸(Lac)、肺功能的影响.方法 选择35例在体外循环下行心内直视人工瓣膜置换术的成年患者,记录麻醉后5 min(T1)、体外循环开始后5 min(T2)、体外循环结束后5 min(T3)、手术结束时(T4)患者的COP、Lac、动脉血气分析等数据,记录T1、T3、T4时肺容量-压力曲线中的达因(Cdyn)、气道压峰值(Peak)、吸入氧浓度(FiO2)数据,计算氧合指数(OI),比较各时间点数据的差异.结果 35例患者中获得有效数据32例,体外循环开始后COP明显降低,T2、T3、T4时COP明显低于T1时(P<0.01).体外循环开始后血清Lac逐渐升高,持续至手术结束,T2、T3、T4时明显高于T1时(P<0.01),T3、T4时明显高于T2时(P<0.05).T3、T4时OI均明显低于T1时(P<0.05).T3时Cdyn明显低于T1时(P<0.05).结论 心脏外科手术体外循环导致COP降低,Lac增高,损害肺功能,提高术中血浆COP有利于减轻组织水肿,改善肺功能.%Objective To observe the changes of plasma colloid osmotic pressures(COP) , blood lactic acid level and lung function in patients undergoing valve replacement surgery. Methods 32 patients received heart valve replacement surgery during extra-corporeal circulation. Plasma COP, blood lactic acid, arterial blood analysis of all patients were measured at 5 min after anaesthesia (Tl),5 min after the begin of cardiopulmonary bypass(T2),5 min after the end of cardiopulmonary bypass (T3), and the end of surgery(T4). The values of dynamic compliance(Cdyn) ,peak airway pressure(Peak) ,oxygenation Index(OI) were calculated at time points of T1,T3,T4. All changes in these variables were analyzed and the relationship between the COP and blood lactic acid,lung function was analyzed. Results The level of COP decreased significantly after beging of cardiopulmonary bypass in patients,and the levels of COP at time points of T2,T3,T4 significantly lower than that at time points of Tl(P<0. 01). The value of blood lactic acid in patients increased significantly,and it maintained until at the end of surgery. The levels of blood lactic acid in patients at time points of T2 ,T3 ,T4 significantly higher than that at time points of Tl(P<0. 01). The levels of OI in patients at time points of T3, T4 were significantly lower than that at time points of Tl(P<0. 01). The level of Cdyn in patients at time points of T3 was significantly lower than that at time points of Tl(P<0. 05). Conclusion Extracorporeal circulation can decrease the level of COP, increase the level of blood lactic acid and damage lang function in patients received heart valve replacement surgery. Maintaining higher level of COP maybe produced the effect of reduced edema injury and improving pulmonary function.