Abstract
After the cessation of circulation, organ function deteriorates. In cadaveric lung transplantation, protecting the endothelium of the pulmonary artery (PA) from warm ischemic injury is important. We studied the effects of flush height, reperfusion flow rate, and magnesium on the PA in an isolated, non-blood-reperfused lung model (rabbits, n=6 in each group) . A lowpotassium dextran solution was infused into the PA from a height of 60 cm (groups 1 and 2) or 30 cm (groups 3 through 5), immediately (group 1) or 2 hours (groups 2 through 5) after death. The heart-lung bloc was excised, ventilated, and reperfused at a flow rate of 100 ml/minute (groups 1 through 3) or 50 ml/minute (groups 4 and 5) for 30 minutes. MgCl2 was added to the flush solution (10 mmol/1) in group 5. The pulmonary arterial pressure (PAP) during the flush period (PAPFP) and the flush flow rate (FFR) were recorded. Airway pressure (AWP) and PAP were monitored during the 30-minute reperfusion. After reperfusion, the wet/dry weight ratio (W/D) of the left lung was calculated as an estimate of the extent of lung edema. In group 2, lung failure, indicated by a frothy bronchial exudate, appeared in all animals during the flush period. In group 3, PAPFP was higher and FFR was lower than in group 1, and all lungs failed during the reperfusion period. In group 4, although all lungs were reperfused for 30 minutes, AWP and W/D were higher than in group 1. In group 5, W/D was lower than in group 4. To avoid PA damage caused by overperfusion of the graft, flush height and reperfusion flow rate should be lowered in cadaveric lungs. Magnesium in the flush solution was an effective means of preventing pulmonary edema.
