Beneficial effect of exogenous surfactant in infants suffering acute respiratory distress syndrome after cardiac surgery

Abstract

Objectives: The efficiency of exogenous pulmonary surfactant for pediatric patients suffering acute respiratory distress syndrome after cardiac surgery remains indeterminate. This study explored (1) whether use of exogenous surfactant improved recovery for patients suffering postoperative acute respiratory distress syndrome and (2) whether kinetic analysis of pulmonary functional change was helpful to indicate an appropriate dosing scheme.

Methods: Pediatric patients receiving an exogenous surfactant due to acute respiratory distress syndrome after cardiac surgery for congenital heart defects were reviewed from chart records. They were compared with patients without its use despite the same postoperative complication. Oxygenation index and ventilation index were calculated and fitted with a monoexponential function before and after its use. Other outcomes including chest radiography, duration of mechanical ventilation, and intensive care unit and hospital stay were also analyzed.

Results: All patients developing postoperative acute respiratory distress syndrome were infants. Among them, 19 infants received surfactant administration (Curosurf, 100 mg kg⁻¹, treatment group). Twenty-four infants without its administration served as control, though also suffering from the same complication. All infants receiving surfactant survived, whereas three infants in the control group died. The duration of mechanical ventilation or hospital stay was significantly shorter after surfactant administration. The infants received either one (n = 13, one-dose subgroup) or two doses (n = 6, two-dose subgroup) before successful weaning from the ventilator. After the first dose was administered, the maximal rates of oxygen index and ventilation index change were significantly higher for infants in the one-dose subgroup (oxygen index: 2.3 ± 0.9 vs 0.8 ± 0.7, p = 0.009, ventilation index: 12.9 ± 3.8 vs 3.9 ± 2.5, p = 0.007). Shortly thereafter (< 12 h), both parameters in the two-dose subgroup deteriorated and a second dose was administered 24h later.

Conclusions: Exogenous pulmonary surfactant is an efficient medication for infants suffering acute respiratory distress syndrome after cardiac surgery. Kinetics analysis of functional change after initial surfactant use may be referred for early determination of an optimal dosing scheme.