IMPACT OF INITIAL FLUSH POTASSIUM CONCENTRATION OM THE ADEQUACY OF LUNG PRESERVATION

The effects of initial lung flushing with intracellular and extracellu lar fluid type solutions were studied in lungs stored with the Univers ity of Wisconsin solution, Excised Sprague-Dawley rat lungs (n = 39) w ere flushed first with one of the following solutions: (1) the Univers ity of Wisconsin solution (K+ = 140 mmol/L), (2) modified (low potassi um) University of Wisconsin solution (K+ = 20 mmol/L), (3) phosphate b uffered saline solution (K+ = 3.9 mmol/L), (4) modified low-potassium phosphate-buffered saline solution (K+ = 20 mmol/L), (5) modified high -potassium phosphate-buffered saline solution (K+ = 40 mmol/L), and (6 ) Euro-Collins solution (K+ = 115 mmol/L) followed by secondary flush with storage solution and cold (4 degrees C) storage in University of Wisconsin solution for 24 hours, The lungs were then reperfused in the isolated, pulsatile, blood-perfused working lung system for 2 hours o r until lung failure, Blood gas analysis and shunt fraction, aerodynam ic parameters (airway resistance, lung compliance, elastic work, and h ow resistive work), and total pulmonary vascular resistance were measu red throughout the perfusion period, The mean oxygen tensions (in mill imeters of mercury) at 30 minutes after the onset of reperfusion for U niversity of Wisconsin solution, modified University of Wisconsin solu tion, phosphate-buffered saline solution, modified phosphate-buffered saline solutions (20 and 40 mmol/L), and Euro-Collins solution were 56 .1 +/- 4.2, 72.7 +/- 9.1, 87.7 +/- 6.9 (p < 0.01 versus University of Wisconsin solution; p < 0.01 versus Euro-Collins solution), 86.0 +/- 9 .6 (p < 0.01 versus University of Wisconsin solution; p < 0.01 versus Euro-Collins solution), 87.9 +/- 7.7 (p < 0.01 versus University of Wi sconsin solution; p < 0.01 versus Euro-Collins solution), and 53.5 +/- 6.0, respectively, All aerodynamic parameters in the lungs flushed wi th extracellular fluid type solutions were superior to those flushed w ith intracellular fluid type solutions, We conclude that the efficacy of initial flushing was essential for successful lung preservation and that extracellular fluid type solutions were superior to intracellula r fluid type solutions, at least for hushing the lung before storage w ith University of Wisconsin solution, Potassium concentration in flush ing solution should be 20 mmol/L or less to obtain appropriate flushin g and subsequent adequate distribution of the storage solution.