Reliable eighteen-hour lung preservation at 4° and 10° C by pulmonary artery flush after high-dose prostaglandin E₁ administration

Pulmonary preservation is improved by hypothermia, but the optimal preservation temperature is not known. The effects of two different preservation temperatures, 4° and 10° C, on lung function were studied in a canine left lung allograft survival model allowing selective perfusion of either lung. After donor treatment with high-dose prostaglandin E₁, (25 μg/kg), lungs were flushed with modified Euro-Collins solution (50 ml/kg) and stored in Euro-Collins solution for 18 hours at 4° C in group I (n = 8) and 10° C in group II (n = 6). Pulmonary gas exchange and hemodynamics were compared on the day of transplantation (day 0) and 3 days later (day 3). Rapid, high-flow, low-pressure flush was achieved uniformly in both groups (flush time: group I, 35.1 ± 2.4 seconds; group II, 35.3 ± 3.0 seconds; p = 0.96; flush pressure: group I, 9.8 ± 0.7 mm Hg; group II, 10.1 ± 1.1 mm Hg; p = 0.8). Transplanted lungs provided similar excellent oxygenation in both groups on day 0 (arterial oxygen tension, group I, 451 ± 82 mm Hg; group II, 497 ± 37 mm Hg; p = 0.61; inspired oxygen fraction = 1.0) and day 3 (arterial oxygen tension, group I, 551 ± 57 mm Hg; group II, 587 ± 19 mm Hg; p = 0.55), with a statistically significant improvement from day 0 to day 3 in both groups (group I, p = 0.034; group II, p = 0.038). There was no difference in arterial carbon dioxide tension, base excess, cardiac output, blood pressure or pulmonary artery pressure between the two groups. We conclude that a large bolus of prostaglandin E₁ into the pulmonary artery produces a high-flow, low-pressure flush with modified Euro-Collins solution; with this technique, equivalent, reliable 18-hour lung preservation can be achieved at 4° and 10° C flush and storage temperatures.