QS Xing, ST Zhang, HZ Zhang, Y Yang, B Sun

Saturated phosphatidylcholine (PC), total phospholipids (TPL), total protein and surfactant protein A (SP-A) in sequential airway aspirates during open chest operation were determined in children with congenital heart disease. Tetroxide osmium digestion and neutral alumina column chromatography were used to measure saturated PC; a modified immunoblot method with a rabbit anti-human SP-A polyclonal antibody was used to measure SP-A. In 11 patent ductus arteriosus patients with open chest operation only, saturated PC/total phospholipids, saturated PC/total protein and total phospholipids/total protein levels were not changed, but SP-A/total protein was decreased from 21 to 9 ug/mg (P < 0.05, by paired t-test). In 29 atrial septal defect and ventricular septal defect patients with open chest surgery and extracorporeal circulation, but no pulmonary hypertension or cyanosis, saturated PC/total phospholipids was decreased from 45 % to 34 % (P < 0.01), saturated PC/total protein decreased from 54 to 24 μg/mg (P < 0.05), and SP-A/total protein from 23 to 11 μg/mg. In eight ventricular septal defect patients with pulmonary hypertension and 11 tetralogy of Fallot patients with cyanosis, initial saturated PC/total phospholipids was low (37% and 39%, respectively) and was reduced further, and both saturated PC/total protein and SP-A/total protein decreased (P < 0.05) during the operation. These results suggest that a decrease of pulmonary surfactant and/or an increase of vascular-to-alveolar permeability occurs in children with congenital heart disease, especially those with ventricular or atrial septal defect or tetralogy of Fallot, during open chest operation. The saturated PC/total protein and SP-A/total protein changes are sensitive indicators for pulmonary surfactant production. Whether there is any persistent surfactant deficiency in children with ventricular septal defect with pulmonary hypertension or with tetralogy of Fallot warrants further investigation. (In part supported by Nestle [Germany] Research Funds and Shanghai Education Foundation to B.S.)