Inhaled Nitric Oxide as a Prophylactic Treatment Against Reperfusion Injury of the Lung

Abstract

Background: Inhaled Nitric Oxide (NO) has been found to be effective in clinical treatment of reperfusion injury after lung transplantation. This study was designed to determine a possible prophylactic role to reduce severe reperfusion injury. Methods: In 12 minipigs the left lung was selectively perfused with cold Euro-Collins solution. After 90 minutes of warm ischemia the lungs were reperfused and the contralateral pulmonary artery and main bronchus clamped. Hemodynamic and respiratory parameters were monitored for 7 hours. 6 animals were used as controls. 6 pigs formed the NO group and were ventilated continuously with 40 ppm nitric oxide (NO) starting 30 minutes prior to reperfusion. Results: In the control group right heart failure developed within 1.9 ± 0.8 hours of reperfusion. Lung compliance was significantly reduced. A significant increase of pulmonary vascular resistance (PVR) was found. All animals of the NO group survived the reperfusion period of 7 hours. PVR was decreased compared to controls (p = 0.03). AaDO₂ was lower, but not significantly different. The dynamic compliance of the lung was significantly higher (p = 0.007) in the NO group. Conclusions: The prophylactic institution of inhaled NO reduces reperfusion injury of the lung. Short-term use of inhaled NO should be adopted as a prophylactic agent after transplantation of lungs preserved in Euro-Collins solution.