Protective Effects Of Intermittent Ventilation On Pulmonary Function During Cardiopulmonary Bypass

Objective: To study the protective effects and mechanism of intermittent ventilation on pulmonary function during cardiopulmonary bypass(CPB). Methods: 24 patients with rheumatic heart disease (RHD) were divided into two groups randomizely: (1) treat group (group A,n=13),given intermittent ventilation once every 5 minutes during cardiopulmonary bypass; ( 2 ) control group (group B,n=ll),no ventilation during CPB. Blood samples were obtained preoperatively;A brochioalveolar lavage (BAL) was performed at 2 hours after the end of cardiopulmonary bypass.The numbers of granulocytes, total protein (TP) and tumor necrosis factor- α (TNF-α ) content in the brochioalveolar lavage fluids(BALF) were measured ,and serum total protain were measured too,and lung oxygenate index (OI) were measured preoperatively and 1 hom,4 hours after CPB termination,respectively. Results: The numbers of granulocytes , total protein and TNF- α content of treat group in the BALF was significantly lower than that of the control group (P<0.05),and the lung oxygenate index of treat group at 1 hour and 4 hours after CPB termination was also significantly lower than that of the control group;A significant(P<0.05) increase of lungoxygenate index occurred in both groups at 1 hour and 4 hours after CPB when compared with the same group at baseline before CPB,but serum total protein is no significantly difference between both groups. Conclusions (1) Intermittent ventilation has the protective effects on pulmonary function during CPB. (2) Intermittent ventilation during CPB can attenuate lung injury by decreasing granulocytes adhesion, alleviating lung inflammatory reaction and endothelial cells injury.