Objective: To study the effects of cardiopulmonary by pass(CPB) on pulmonary surfactant (PS) activity.
Method: In 12 children with patent ductus arteriosus(PDA) and 19 patients with ventricular septal defect (VSD), saturated phosphatidylcholine (SatPC), total phospholipids (TPL), total protein (TP) and surfactant protein-A(SP-A) in sequential airway aspirates before and after operation were determined. Tetroxide osmium digestion and neutral alumina column chromatography were used for SatPC, and a modified immunoblot method with a rabbit anti-human SP-A polyclonal antibody for SP-A measurment.
Results: In 19 VSD patients with CPB, SatPC/TPL was significantly decreased from 48% to 34% (t = 2.737, P < 0.05), SatPC/TP decreased from 64 to 33 mg/g (t = 3.011, P < 0.01), and SP-A from 23 to 11mg/g (t = 2.987, P < 0.01). In 12 patients without CPB, SatPC/TPL, SatPC/TP, SP-A/TP levels were not changed.
Conclusions: CPB significantly reduces pulmonary surfactant activity.