OBJECTIVEAcute lung injury is a severe complication after cardiac surgery performed with cardiopulmonary bypass in infant patients. Pulmonary surfactant has been successfully used in treating neonatal respiratory distress syndrome for many years. This study focused on exploring the clinical efficacy of exogenous pulmonary surfactant in treating infant patients with acute lung injury after cardiac surgery with the use of extracorporeal circulation.

METHODTwenty-three infants with ventricular septal defect (VSD) were enrolled in the study. None of the patients needed oxygen treatment nor ventilation before heart surgery. VSD repair operation was done under cardiopulmonary bypass, and acute lung injury was found postoperatively. Ten infant patients in the treatment group were given pulmonary surfactant by tracheal instillation during mechanical ventilating postoperatively. Thirteen patients in control group were randomly selected in the same period in hospital, and acute lung injury was diagnosed without pulmonary surfactant treatment after cardiopulmonary bypass. Blood samples were obtained from all the patients, and blood gas analysis was performed every 6 hours. Demographics (body weigh, age, gender, VSD diameter) and clinical characteristics (CPB time, oxygenation index, mean airway pressure, pH and PCO2) of all the patients were collected, and statistical analysis was done to compare the data between treatment and control group.

RESULTIn the first 24 hours after heart surgery, compared with the control group, a more increased oxygenation index (from 89.36 ± 12.69 to 285 ± 16.51) was observed in treatment group, and it was from 93.71 ± 11.82 to 133 ± 19.62 in the control group. There was a significant difference in oxygenation index between the two groups (P < 0.05). At the same time, the MAP (from 17.5 ± 3.18 to 10.4 ± 3.37) of the patients in comparison with the control group (from 18.2 ± 2.63 to 13.8 ± 2.55), a more significantly decreased MAP was observed in the treatment group (P < 0.05). There was no significant difference in pH and PCO2 between the two groups. The ventilation time in cardiac care unit was shorter in treatment group (17.43 ± 9.12) h compared with the control group [(30.97 ± 14.85) h, P < 0.05]. ICU stay time of treatment group (3.90 ± 1.34) d was shorter than that of control group [(6.18 ± 1.90) d, P < 0.05].Two infants of the control group died, but none in treatment group died.

CONCLUSIONIn this study, a satisfactory curative effect was observed for the treatment of acute lung injury with PS intratracheal instillation after heart surgery under cardiopulmonary bypass in infant patients. It can reduce the duration of mechanical ventilation and cardiac care unit stay and improve prognosis. In addition, this study was a pilot study and the limited sample size was probably the cause of insufficient statistical power. Further study of larger scale is needed.