Influence of the type of congenital heart defects on epithelial lining fluid composition in infants undergoing cardiac surgery with cardiopulmonary bypass

Abstract BACKGROUND: In children with congenital heart disease (CHD), altered pulmonary circulation compromises gas exchange. Moreover, pulmonary dysfunction is a complication of cardiac surgery with cardiopulmonary bypass (CPB). No data are available on the effect of different CHDs on lung injury. The aim of this study was to analyze epithelial lining fluid (ELF) surfactant composition in children with CHD. METHODS: Tracheal aspirates (TAs) from 72 CHD children (age 2.9 (0.4-5.7) months) were obtained before and after CPB We measured ELT phospholipids, surfactant proteins A and B (SP-A, SP-B), albumin, and myeloperoxidase activity. TAs from 12 infants (age 1.0 (0.9-2.9) months) with normal heart/lung served as controls. RESULTS: Heart defects were transposition of great arteries (19), tetralogy of Fallot (TOF, 20), atrial/ventricular septal defect (ASD/VSD, 22), and hypoplastic left heart syndrome (11). Increased levels of ELF SP-B were found in all defects, increased myeloperoxidase activity in all except the TOF, and increased levels of ELF albumin and SP-A only in ASD/VSD patients Postoperatively, ELT findings remained unchanged except for a further increase in myeloperoxidase activity. CONCLUSION: ELT composition has distinctive patterns in different CHD. We speculate that a better knowledge of the ELF biochemical changes may help to prevent respiratory complications.