Respiratory insufficiency is the prime indication for lung transplantation. Clinically, there have been five recipients in whom the allograft as the only lung(s) was able to support life up to eight days.1 Experimentally, Veith and Richards have obtained canine survivors following unilateral lung transplantation and contralateral pulmonary artery ligation.2 Thus, there is no question that lung transplants can function immediately after ventilation and circulation are established. The degree to which function is sustained and the serial evaluation of pulmonary reserve after lung transplantation are less well documented. The need for further information concerning pulmonary allograft function during the entire early postoperative period is enhanced by the lack of means for prolonged extracorporeal auxiliary respiration.
In view of the fact that human lung transplant experience at the time of writing is limited to 23 operations by 20 surgeons on three continents, it is clear that laboratory work is still important in