LOW-POTASSIUM SOLUTION FOR LUNG PRESERVATION IN THE SETTING OF HIGH-FLOW REPERFUSION

Background. We previously demonstrated that standard preservation usin g Euro-Collins solution impairs lung function in the setting of high-f low reperfusion because of potassium-induced vasoconstriction. Preserv ation strategies for single-lung transplantation are an important fact or in patients with pulmonary hypertension. This study investigates th e hypothesis that low-potassium preservation solution will improve fun ction of lungs subjected to high-now reperfusion. Methods. Twenty-one New Zealand white rabbit lungs were harvested and studied on an isolat ed, blood-perfused model of lung function after 4 hours of cold ischem ia at 4 degrees C. Control lungs were preserved with 50 mL/kg of cold saline solution flush (group I). Experimental lungs were preserved wit h low-potassium solution (group II) or Euro-Collins solution (group II I) at similar temperatures and volumes. Results. The pulmonary arterio venous oxygen gradient at the end of the 30-minute high-flow reperfusi on period was significantly higher in group II compared with group III (121.3 +/- 19.2 mm Hg versus 31.1 +/- 4.2 mm Hg; p < 0.001). The pulm onary vascular resistance was significantly lower in group II than in group III (46.3 +/- 1.8 x 10(3) dynes . s . cm(-5) versus 79.8 +/- 8.4 x 10(3) dynes . s . cm(-5); p < 0.01). The percent decrease in dynami c airway compliance in group III was significantly greater than in gro ups I and II (-51.0% +/- 13.3% versus -10.2% +/- 3.4% and -11.2% +/- 2 .8%, respectively; p < 0.001). Similarly, the wet to dry ratio of the lungs in group III was significantly greater than in groups I and II ( 13.9 +/- 2.3 versus 5.9 +/- 0.2 and 6.0 +/- 0.4, respectively; p < 0.0 01). Conclusions. These data demonstrate that a low-potassium preserva tion solution yields improved lung function after high-now reperfusion in an ex vivo rabbit lung model. Lung preservation should be aimed at the clinical setting.