血液超滤对高原地区体外循环围术期肺功能变化的影响

目的:观察拉萨高原地区体外循环(CPB)围术期呼吸指数(RI)、肺顺应性等肺功能指标的动态变化,探讨血液超滤技术对CPB后肺功能的保护作用.方法:选择2001年6月至7月在海拔3 700 m开展的CPB心内直视手术患者10例,根据CPB过程中有无应用血液超滤技术,将患者分成血液超滤组(n=5)和对照组(n=5),各组均分别于CPB前、主动脉开放后5 min、CPB结束时、以及CPB后60、120、240 min,测定气道平台压(PPlateau)、气道峰压(PAP)、静态胸肺顺应性(Cs)、动态胸肺顺应性(Cd)和RI的变化.结果:全组无早期死亡.所有患者在CPB转流中及转流后均未出现血红蛋白尿.与CPB前相比,对照组在主动脉开放后5 min至CPB后240 min各时间点,其RI、PPlateau和PAP均显著升高(P<0.05),Cs、Cd均明显降低(P<0.05);血液超滤组在主动脉开放后5 min至CPB后60 min,其PPlateau、PAP和RI虽较CPB前有增加趋势,Cs、Cd有降低趋势,但均无统计学意义(P>0.05);主动脉开放后各时间点,对照组PPlateau、PAP和RI均较血液超滤组明显升高(P<0.05),而Cs、Cd较血液超滤组明显降低(P<0.05).结论:高原地区CPB可引起明显的肺功能急性受损;CPB中应用血液超滤技术能明显减轻术后的急性肺损伤.

Effects of ultrafiltration on pulmonary function after cardiopulmonary bypass at high altitude

Objective: To evaluate the effect of cardiopulmonary bypass (CPB) on perioperative pulmonary complianceand respiratory index (RI), and to elucidate the protective effect of ultrafiltration on pulmonary function after CPB in childrenat high altitude. Methods: Ten patients of congenital heart defect (CHD) with pulmonary hypertension underwent operativerepair under CPB at an altitude of 3 700 meters and were randomized into ultrafiltration group (UF group) and control groupaccording to with or without ultrafiltration technique during CPB. There were 6 Tibetan and 4 Tibetan-born Hans with a meanage of 4. 9 years (2-12 years ). Plateau airway pressure (PPlateau), peak airway pressure (PAP),RI,static pulmonary compliance(Cs) and dynamic pulmonary compliance (Cd) were all measured or calculated after induction of anesthesia, 5 min after aorticunclamping, and 5, 60, 120, 240 min after weaning CPB. Results: There was no operative death, and no hemoglobinuria wasfound during and after CPB in all patients. PPlateau, PAP and RI were statistically elevated (P<0.05) and Cs and Cd signifi-cantly reduced (P<0.05) during and after CPB in control group when compared with that before CPB,while in UF groupthere were no statistical difference in Pplateau,PAP,RI,Cs and Cd as compared with that before CPB. Moreover,PPlaeau.,PAP,RI, Cs and Cd were significantly improved in UF group when compared with control group (P<0.05 ). Conclusion:CPB at thehigh altitude can result in a significant acute lung injury. Utrafiltration produces a market improvement in pulmonary func-tion,especially the pulmoriary compliance after CPB in CHD children.