INFLUENCE OF THE PERFUSATE TEMPERATURE ON LUNG PRESERVATION - IS THERE AN OPTIMUM

The optimal temperature of the pulmonary flush perfusate is still a ma tter of controversy, At present, a temperature of 10 degrees C is favo red, This study deals with the structural and functional impact of dif ferent perfusate temperatures on lung preservation, In an extracorpore al rat heart-lung model lungs were preserved with Perfadex(R) solution of 4, 15 and 25 degrees C and submitted to 2 h ischemia. Heart-lung b locks harvested from male rats were perfused with Krebs-Henseleit solu tion and ventilated with room air. Lungs were perfused with deoxygenat ed perfusate via the working right ventricle while the coronary arteri es were retrogradely perfused with oxygenated perfusate. Oxygenation c apacity (dPO(2)), peak inspiratory pressure (PIP) and pulmonary vascul ar resistance were measured. After establishment of baseline functiona l parameters hearts were arrested with 10 mi St, Thomas cardioplegia a nd lungs were flushed with 20 mi Perfadex solution, The heart-lung blo ck was then stored for 2 h at 10 degrees C, Reperfusion was performed thereafter under the same conditions, At the end of the trial the lung tissue water was measured by the wet/dry ratio, The perfusion time of the groups flushed with 15 or 25 degrees C perfusate was significantl y lower than that of the 4 degrees C group, After 20 min reperfusion d PO(2) of the groups flushed with 15 or 25 degrees C was superior to th ose submitted to a 4 degrees C flush perfusion, PIP was significantly lower in the 15 degrees C group than in the 4 and 25 degrees C groups, The wet/dry ratio revealed the smallest water content in the 15 degre es C group, We conclude that the postischemic lung function is depende nt on the temperature of the flush perfusate, Among the tested tempera tures, perfusion at 15 degrees C showed the best results, The optimum may therefore lie in this range.