Ventilation in situ after cardiac death improves pulmonary grafts exposed to 2 hours of warm ischemia

Background. The pulmonary donor pool would increase substantially if lungs could be donated after cardiac death (DCD). There have been ethical and legal obstacles since administration of heparin and cooling has to be done immediately after cardiac death. This study examines whether ventilation of DCD lungs without administering heparin or cooling the lungs after cardiac death could improve graft function. Method. Twelve donor pigs with a mean bodyweight of 70 kg were randomized into two groups. Six animals were ventilated in situ with 50% oxygen, 4 L/min, and 5 cm H2O in positive end-expiratory pressure or PEEP for 2 h after cardiac death. Six animals served as non-ventilated controls and were exposed to warm ischemia for 2 h. After 2 h, all lungs were harvested and flush perfused with Perfadex (R) solution and stored at 8 degrees C for another 2 h. An ex vivo lung perfusion or EVLP circuit was used for evaluation. Results. Non-ventilated lungs developed pulmonary edema, and had highly impaired blood gas levels and a significantly increased weight. The ventilated lungs demonstrated excellent blood gas levels and unchanged weight. Conclusion. The increase in tolerable warm ischemic time in combination with avoiding heparinization and cooling might facilitate the use of DCD lungs for transplantation.