Levels Of Plasma Nitric Oxide, Endothelin, And Adrenomedullin During Cardiopulmonary Bypass And The Effects Of Milrinone Combined With Nitric Oxide To Treat Pulmonary Hypertension After Surgery In Patients With Congenital Heart Disease And Pulmonary Hyper

Objectives To evaluate the effect and clinical significance of nitric oxide (NO), adrenomedulin (ADM) and endothelin (ET-1) peri-cardiopulmonary bypass(CPB) by detecting their levels of patients in congenital heart disease(CHD) and pulmonary hypertension, and investigate the effect of milrinone combined with nitric oxide(NO) on pulmonary artery pressure after cardiopulmonary bypass(CPB).Methods①36 patients with congenital heart disease who had left-to-right shunt were selected. They were divided into three groups according to pulmonary artery systolic pressure (PASP): group 1 with a normal pulmonary pressure (PASP < 30 mm Hg, n = 8), group 2 with a mild pulmonary hypertension (PASP30~50 mm Hg, n = 15), group 3 with moderate or severe pulmonary hypertension (PASP>50 mm Hg, n = 13). The plasma levels of ADM, NO and ET were detected at pre-operation, onset of CPB, weaning from CPB and 3 hours, 6 hours, 24 hours after CPB. The interrelation between them and PASP was analyzed.②18 patients with CHD and PASP>50 mm Hg scheduled for open heart surgery randomed divied into three groups: group N( inhaled NO, n=6), group M (milrinone group, n=6)and group NM(combined group, n=6), after weaning from CPB, group N and group M were treated with NO and milrinone respectively, group NM , with double drugs. Pulmonary pressures, systemic pressure and CI, PVRI, SVRI, Pp/Ps, Rp/Rs values were recorded before bypass, after weaning from CPB, 15and 30 minutes after starting each rigimen and 15 after the cessation of NO treatment. Results①Following the severity degree of pulmonary hypertension, the plasma levels of ADM increase. There is positive correlation between PASP and plasma level of ADM(r=0.858);②Plasma levels of NO and ET in groups with PAH was higher than that in group with non-PAH, but there is no difference between group 2 and group 3;③Plasma level of ADM and ET of each group after CPB was higher than that of each group before operation;④The plasma levels of NO of group2 and group3 after CPB was lower than that before operation.⑤I n NO group inhalation NO can significantly decreased the mPAP(22.4±16.4)% and PVR (32±24.4)%, but returned to higher level after acute NO withdrawal;⑥In M group, milrinone decreased PVR by(30±11.6)% but did not change mPAP significantly;⑦n combination group, milrinone and NO can decreased mPAP by (25.5±3.5)% and PVR (30.6±13.3)%,when NO withdrawal, mPAP and PVR did not change significantly. Conclusion①Following the severity degree of pulmonary hypertension, the plasma levels of ADM increase. ADM, ET and NO should play an important role in the formation of PAH, restructure and post-operative PAH; CPB can cause the ADM and ET levels up and NO level down;②both NO and milrinone can decrease pulmonary artery resistance individually, and the combination may produce selective pulmonary vasodilation after CPB in CHD and PAH patients and prevent rebound PAH.