Surfactant improves graft function after gastric acid-induced lung damage in lung transplantation

The number of available donor lungs is still the limiting factor in lung transplantation. We have recently shown that diluted surfactant lavage during ex vivo lung evaluation improved the graft function after gastric acid aspiration. In the present study, we hypothesized that diluted surfactant administration would recondition and improve the graft function after acid aspiration-induced lung injury in a porcine model of pulmonary transplantation.

Left lung injury was induced by intrabronchial administration of 1 mL/kg betaine HCl and pepsin mixture. The animals were subsequently ventilated for 24 hours. After organ retrieval, the donor lungs were stored at 4°C for 4 hours. In the control group, left lung transplantation was performed without any surfactant treatment. In the surfactant group, the recipients received intratracheal diluted surfactant lavage just before reperfusion and ventilation. During 7 hours of reperfusion, the hemodynamic and respiratory variables were recorded on an hourly basis.

Surfactant lavage resulted in lower mean pulmonary artery pressure, higher mixed venous oxygen saturation, and better oxygenation compared with the control group (p = 0.001). Bronchoalveolar lavage interleukin-6 level, protein, and neutrophil percentage at the end of the experiment were significantly higher in the control group compared with the surfactant group (p = 0.03). Minimal surface tension was significantly lower in the surfactant group compared with controls (p = 0.03).

These results demonstrate that application of diluted surfactant before reperfusion can be used effectively to improve the graft function from donor lungs injured by gastric acid aspiration.