Improved static lung preservation with corticosteroids and hypothermia.

With methylprednisolone as a chemical inhibitor of leukocytes, extended preservation was conducted with an isolated rabbit lung model. The heart-lung blocks of 39 New Zealand white rabbits were flushed in situ with 100 ml of Euro-Collins' solution, harvested, inflated (70%), and preserved at 4 degrees C. Lungs immediately reperfused with whole blood (control lungs, group 1) were compared with lungs preserved without methylprednisolone for 5, 12, and 24 hours (groups 2 to 4) and those preserved with methylprednisolone for 12 and 24 hours (groups 5 and 6, respectively). Methylprednisolone (30 mg/kg) was administered before harvest and was used as an additive to the flush and in the blood reperfusate. Hypothermia and Euro-Collins' flush alone provided adequate preservation for up to 5 hours; however, lung edema was evident by 12 hours of cold ischemia and became severe by 24 hours. By all measured parameters, the lungs in group 5 (treated with methylprednisolone) demonstrated values equal to or better than control lungs. By 24 hours of preservation the beneficial effects of the steroid treatment were no longer evident. Histologic evaluation revealed mild to moderate injury after 5 hours of cold ischemia; progressive edema and hemorrhage were found after 12 and 24 hours of preservation. This injury was significantly ameliorated by methylprednisolone treatment at 12 hours but not at 24 hours. This study suggests that static preservation for up to 5 hours is possible with hypothermia and a Euro-Collins' flush and that extended preservation to 12 hours is possible with pharmacologic dosages of methylprednisolone.(ABSTRACT TRUNCATED AT 250 WORDS)