Single lung transplantation may be performed without pump oxygenation in the majority of patients. From April 1987 to August 1989, 3 of 12 patients undergoing single lung transplantation required pump oxygenation. One patient required pump oxygenation because of a marked drop in oxygen saturation during test clamping of the pulmonary artery; one patient was brought to the operating room while receiving extracorporeal membrane oxygenation; and one patient had such markedly elevated pulmonary artery pressures that pump oxygenation was used to lower pressure in the pulmonary circuit, allowing safe pulmonary artery clamping. These three patients had cannulas placed in the femoral vein and femoral artery. The latter two patients manifested marked upper body oxygen desaturation while maintaining excellent lower body oxygen saturation during their transplant procedures. Ventricular fibrillation, induced by alternating current, was used as a means to correct this differential perfusion. Should pump oxygenation be necessary during single lung transplantation, the region of the body adjacent to the arterial cannula may be perfused with oxygenated blood, and the remainder of the patient may be perfused with deoxygenated blood. Induced ventricular fibrillation is one method to correct this potentially fatal problem.