Both blood and crystalloid-based extracellular solutions are superior to intracellular solutions for lung preservation

Objective: Lung transplantation remains limited by donor organ ischemic time, inadequate graff preservation, and reperfusion injury. We evaluated long preservation with use of an extracellular solution, with or without the addition of blood, as compared with preservation with the intracellular Euro- Collins solution. Methods: With use of an isolated, whole blood perfused/ventilated rabbit lung model, we studied three groups of animals. Lungs were flushed with Euro-Collins, low-potassium dextran, or 20% blood- low-potassium dextran solution. Longs were harvested en bloc, stored inflated at 4° C for 18 hours, and then reperfused at 60 ml/min with whole blood. Continuous measurements of pulmonary artery pressure, pulmonary vascular resistance, and dynamic airway compliance were obtained. Fresh, nonrecirculated venous blond was used to determine the single-pass pulmonary venous-arterial oxygen gradient. Results: Lungs preserved with Euro-Collins solution demonstrated elevated pulmonary artery pressure and pulmonary vascular resistance when compared with those preserved with low-potassium dextran and 20% blood-low-potassium dextran solutions (pulmonary artery pressure: 40.8 ± 2.2 mm Hg vs 28.9 ± 2.4 mm Hg and 28.3 ± 1.5 mm Hg, respectively, p < 0.001; pulmonary vascular resistance: 46.0 ± 3.1 x 10³ dynes · sec · cm^-5 vs 29.0 ± 4.2 x 10³ dynes · sec · cm^-5 and 28.8 ± 2.3 x 10³ dynes · sec · cm^-5, respectively, p < 0.001). Euro-Collins solution-preserved lungs demonstrated a significant drop in compliance when compared with those preserved with low-potassium dextran and 20% blood-low- potassium dextran (-21.9% ± 4.7% vs 1.8% ± 3.3% and 1.4% ± 6.2%, respectively; p = 0.002). Oxygenation was improved with low-potassium dextran and 20% blood-low-potassium dextran solutions as compared with that with Euro-Collins solution (296.3 ± 54.6 mm Hg and 290.2 ± 66.4 mm Hg, respectively, vs 37.2 ± 4.6 mm Hg; p = 0.001). Conclusions: Extracellular solutions provided superior preservation of pulmonary function in this rabbit lung model of ischemia-reperfusion. However, the addition of blood does not confer any demonstrable advantage over low-potassium dextran solution alone with use of an 18-hour period of cold ischemia.