Effect of low-dose exogenous surfactant on infants with acute respiratory distress syndrome after cardiac surgery: a retrospective analysis

BACKGROUND: Acute respiratory distress syndrome (ARDS) in infants undergoing cardiac surgery is associated with significant mortality and prolonged ventilation; surfactant administration may be a useful therapy. The purpose of this study is to evaluate the effect of low-dose exogenous surfactant therapy on infants suffering ARDS after cardiac surgery. METHODS: We conducted a case-control study of infants diagnosed with moderate-to-severe ARDS (PaO(2)/FiO(2) < 150) after cardiac surgery. A case was defined as a patient that received surfactant and standard therapy, while a control was defined as a patient that underwent standard therapy. The primary endpoint was the improvement in oxygenation index (OI) after 24-h of surfactant treatment; and secondary endpoints were the ventilator time and PICU time. RESULTS: Twenty-two infants treated with surfactant were matched with 22 controls. Early low-dose (20 mg/kg) surfactant treatment was associated with improved outcomes. After surfactant administration for 24-h, the surfactant group was much better compared with the control group at the 24-h in OI (difference in average change from baseline, − 6.7 [95% CI, − 9.3 to − 4.1]) (P < 0.01) and ventilation index (VI, mean difference, − 11.9 [95% CI, − 18.1 to − 5.7]) (P < 0.01). Ventilation time and PICU time were significantly shorter in the surfactant group compared with the control group (133.6 h ± 27.2 vs 218.4 h ± 28.7, P < 0.01; 10.7d ± 5.1 vs 17.5d ± 6.8, P < 0.01). Infants in the surfactant group under 3 months benefit more from OI and VI than the infants over 3 months in a preliminary exploratory analysis. CONCLUSIONS: In infants with moderate-to-severe ARDS after cardiac surgery, early low-dose exogenous surfactant treatment could prominently improve oxygenation and reduce mechanical ventilation time and PICU time. Infants younger than 3 months may get more benefit of oxygenation than the older ones. Randomized controlled trials are needed to explore the effect of surfactant to ARDS of cardiac surgical infants.