BENEFICIAL EFFECT OF INITIAL WARM CRYSTALLOID REPERFUSION IN 6-HOUR LUNG PRESERVATION

Background: To achieve successful lung transplantation, it is essentia l to minimize reperfusion injury occurring as a result of metabolite a ccumulation during the preservation period or at the time of initial i nteraction of blood with constricted pulmonary vasculature. Initial re perfusion with warm crystalloid solution may be advantageous in preven ting this injury. Methods: This study was designed to evaluate the eff ect of low-potassium (4 mmol/L) dextran (1%) solution as the; initial warming solution after 6 hours of hypothermic storage. In 23 New Zeala nd White rabbits the lungs were flushed with low-potassium dextran sol ution (10 degrees C, 40 ml/kg, 600 cm H2O), excised, inflated with roo m air, and stored in a low-potassium dextran solution (10 degrees C) f or 6 hours. After storage, the lungs were divided into two groups. Gro up I (n = 8) was reperfused with warm low potassium dextran for 4 minu tes, at 37 degrees C followed by blood reperfusion for 30 minutes at 3 7 degrees C. Group II (n = 15) was reperfused only with blood for 30 m inutes at 37 C. The mean pulmonary vascular resistance measured during cold flush and prior to storage was similar in both groups (group I = 20.0 +/- 5.9 mm Hg . sec/ml, group II = 19.3 +/- 1.9 mm Hg . sec/ml). Results: During reperfusion, only 4 of the 15 lungs in group II maint ained an acceptable (<80 mm Hg) mean pulmonary artery pressure; six fa iled immediately. All eight lungs in group I completed the 30-minute r eperfusion (p < 0.005). The mean pulmonary artery pressure was signifi cantly less, and effluent oxygen tension was significantly greater in group I during reperfusion. Conclusions: In this experimental model, i nitial warm reperfusion with low-potassium dextran ameliorated the del eterious effects of reperfusion, thus providing an environment to impr ove lung preservation.