体外循环后肺表面活性物质与肺功能的关系

The Relationship between Changes of Pulmonary Surfactant and Respiratory Function after Cardiopulmonary Bypass

研究体外循环对肺表面活性物质（ＰＳ）的影响，以及体外循环后ＰＳ异常与肺功能不全的关系。分别采用Ｂａｒｔｌｅｔ法、Ｍａｓｏｎ法、改良Ｌｏｗｒｙ法测定１０例非体外循环病人和２０例体外循环手术病人气道吸出物中总磷脂、饱和卵磷脂、总蛋白的含量，并同步测定呼吸指数。结果显示，体外循环术后ＰＳ水平非常显著减低（Ｐ＜０．０１），呼吸指数非常显著增高（Ｐ＜０．０１），且二者间呈显著负相关性（ｒ＝－０．８７，Ｐ＜０．０１）。而非体外循环手术后ＰＳ水平及呼吸指数未见明显变化（Ｐ＞０．０５）。证实体外循环可明显降低ＰＳ的活性，体外循环术后ＰＳ异常与呼吸功能不全密切相关。应用外源性ＰＳ治疗体外循环术后呼吸功能不全，在理论上是可行的。

Aim:To elvaluate the effect of cardiopulmonary bypass (CPB) on pulmonary surfactant (PS) activity and its relationship to respiratory function in children.Clinical material and method:Thirty patients were divided into two groups.NonCPB group consisted of 10 patients with patent ductus arteriosus and CPB group consisted of 20 patients with ventricular septal defect.The tracheal aspirate was obtained before and after surgery for measuring content of total phosphorus (TPL),saturated phosphatidycholine (SPC) and total protein (TP).Arterial blood was taken for gas analysis and inspirate oxygen concentration was measured. The respiratory index (RI) was calculated using previous described formulas.Result:In CPB group,SPC/TPL was decreased significantly from a mean of 51.4% to 48.7% (p<0.01),SPC/TP reduced from a mean of 2.9% to 2.3% (p<0.01).The respiratory index was mardedly increased from a mean of 0.54 to 0.72 (p<0.01) after CPB.There was a negative correlation between PS activity and RI.No significant changes were found in nonCPB group after surgery.Conclusion:Cardiopulmonary bypass significantly reduces pulmonary surfactant activity.The incidence of postoperative respiratory disfunction after CPB is closely related to the reduction of pulmonary surfactant activity.