体外循环控制氧分压对法洛氏四联症患者肺保护作用

Protective effects of controlling arterial oxygen partial pressure during cardiopulmonary bypass on lung in patients with tetralogy of Fallot

目的:研究成人法洛氏四联症患者体外循环中不同氧分压对术后肺换气功能的影响。方法:选择在我院接受法洛氏四联症矫治术的成人患者27例,根据其体外循环中是否控制氧分压分为两组,I组:CPB中给予纯氧,全程PaO2>200(200～500mmHg);II组:CPB开始时给予氧浓度(FiO2)21%～30%,维持于PaO280～100mmHg,CPB中根据体温、灌注流量调节FiO221%～50%,维持于PaO2100～150mmHg左右。记录气管内插管留置时间,测定其术前,CPB后2h、12h、24h、48h的动脉血气结果,计算肺泡-动脉血氧分压差(A-aDO2)。结果:气管内插管留置时间I组长于II组(P<0.01);A-aDO2在术后都升高,在CPB后各观察点,I组比II组升高更多(P<0.05、P<0.01)。结论:体外循环中控制氧分压(PaO2<150mmHg)可以在一定程度上减轻成人法洛氏四联症患者术后肺换气功能的损伤。

Objectlve：To evaluate the protective effect of controlling arterial oxygen partial pressure during cardiopulmonary bypass（CPB） on lung in patients with tetralogy of Fallot. Methods： Twenty-seven adults suffering from tetralogy of Fallot（TOF） undergoing repairing operation were divided into 2 groups.Group Ⅰ（n=12） had CPBgone at anFiO2of 100%,and maintained PaO2 200to500 mmHg. Group Ⅱ （n=15） had CPB initiated at anFiO2 of21%- 30%, and maintained PaO2 from SO to 100mmHg,thengradually increasing FiO2 levels based on body temperature and pump flow, and maintained PaO2 100 to 150 mmHg①Mechanical ventilating time was recorded.②Arterial blood samples were collected for determination of FiO2, PaO2 and PaCO2 before anesthesia and post CPB（2 h,12 h,24 h,48 h）, and AaDO2 was calculated. Results： Mechanical ventilating time in group Ⅱ was significantly shorter than that in Group 1（23.1±2.3 h vs 28.0±3.3 h,P〈0.01）. A-aDO2 had not significantly difference between two groups before anesthesia. After CPB A-aDO2was significantly lower than that in group Ⅰ （P〈0.05. P〈0.01）. Conclusion： Controlling PaO2 during cardiopulmonary bypass provides better pulmonary protection in patients with tetralogy of Fallot.