Pulmonary surfactant changes and its clinical significance after cardiopulmonary bypass in neonates with congenital heart disease

Abstract

Objective To determine whether or not the changes of surfactant occur in neonates undergoing condiopulmonary bypass (CPM) surgery. Methods A total of 25 infants with congenital heart disease aged under 30 days were recruited. There were 19 males and 6 females with an average age of 20.9 (7-30) days and an average weight of 3.8 (2.6-4.6) kg. The grades of Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1) were II-IV. Blood samples were collected from 25 patients and serial plasma concentrations of surfactant protein A (SP-A) measured with enzyme-linked immunosorbent assay. They were divided into delayed (n=8) and control (n=17) groups according to whether or not the duration of intensive care unit (ICU) was longer than 7 days. Results At 2-120 h post-operation, the plasma concentration of SP-A increased time-dependently, including two peaks at 12 and 72 h. The average age and body weight of delayed group were less than those of control group (13.0±4.1 vs 25.6±4.7 days; 2.4±0.6 vs 4.9±2.2 kg). And operative blockage time and CPB were longer in delayed group than control group (94±22 vs 62±16 min; 181±18 vs 120±14 min). The mean mechanical ventilation time was longer in delayed group than control group (8.2±7.3 vs 1.5±0.9 days). There was a higher incidence of postoperative complications in delayed group than control group (50.0% vs 5.9%, P<0.05). The serum level of SP-A after 12h was significantly higher in delayed group than that in control group. And a strong correlation existed between the level of SP-A after 12h and ICU duration. Conclusions The serum concentration of SP-A increases after CPB in neonates. The higher concentration of SP-A, the more a patient is prone to ICU retention. Thus SP-A is a new type of biomarker for alveolar capillary injury. Key words: Cardiovascular abnormalities; Heart disease; Extracorporeal circulation; Pulmonary surfactants