Does PGE1 attenuate potassium-induced vasoconstriction in initial pulmonary artery flush on lung preservation?

The standard clinical protocol for lung transplantation employs cold single pulmonary artery flush with Euro-Collins solution or the University of Wisconsin solution. Prostaglandin E1 (PGE1) is usually given by direct injection into the pulmonary artery to reduce pulmonary vasoconstriction caused by these intracellular, high-potassium solutions, however, the efficacy of PGE1 on lung preservation remains controversial. In this study we demonstrated that vasodilator effects of PGE1 were markedly reduced under a high-potassium condition, and that potassium-induced pulmonary vasoconstriction were inhibited by calcium channel blocker nifedipine. There are three therapeutic options in the cold single pulmonary artery flush for optimal lung transplantation, including the use of a higher dose of PGE1, use of the calcium channel blocker instead of PGE1, or the use of the extracellular, low-potassium solution such as low-potassium dextran solution for initial pulmonary artery flush before the lung harvest.