Protective Effect Of Lipo-Prostaglandin E₁ On Lung In Patients Of Cardiac Valve Replacement During Cardiopulmonary Bypass

Objective : To study lung injury of cardiac value replacement during cardiopulmonary bypass (CPB) and the protective effect and mechanism of Liposomal delivery of prostaglandin E1(Lipo-PGE1).Methods : 24 patients scheduled for cardiac value replacement for the first time were randomized into two groups : control group (C, n=12) and Liposomal delivery of prostaglandin E1 teatment group (P, n = 12). In P group Lipo-PGE1 10ng/kg/min was given at the beginning of CPB and 10ng/ml was added in primiing fluid; while in control group normal saline was given instead of Lipo-PGE1. Pulmonary dynamic compliance (Cd) were measured at preCPB, 10 minutes after declamping of vena cava, at termination of CPB and at the end of operation. At the same time points arterial and mixed venous blood samples were taken for determination of polymorphonuclear leukocyte(PMN) count, intrapulmonaryn PMN trapping (PMNa-PMNv) , blood gases , calculation of PaO2/FiO2 and respiratory indexes (RI). Meanwhile , Interleukin-8 were measured.Results : In control group PaO2/FiO2 and Cd were significantly deteriorating after vena cava declamping as compared with the baseline valves (P<0.05), while in P group no significant changes were seen and the difference between the two groups was significant (P<0.05). RI in group C increased significantly during and post- CPB(P<0.05); RI was significantly lower in group P than in group C during the post-CPB (P< 0.05). In both groups PMN count in arterial and mixed venous blood were significantly increased after vena cava declamping. In control group the intrapulmonary PMN trapping was increased at 1 Omin after vena cava declamping as compared with the baseline (P<0.05). while in P group no significant changes were seen and the intrapulmonary PMN trapping was significantly lower in group P than in group C (P<0.05). The plasma concentration of IL-8 in group C increased significantly during and post-CPB (P<0.05); IL-8 in group P also increased, but the level was significatly lower than that in group C (P<0.05).Conclusion : This study demonstrated that CPB could lead to systemic inflammation , PMN activated and IL-8 released, which caused OI and Cd decrease and RI increase. Lipo-prostaglandin E1 can obviously reduce lung injury during cardipulmonary bypass by decreasing PMN trapping and IL-8 releasing.