Inhaled NO and prostacyclin during porcine single lung transplantation

Background. Increased pulmonary vascular resistance (PVR) and decreased art erial oxygenation frequently complicate lung transplantation. Inhaled nitri c oxide (NO) and aerosolized prostacyclin (PGI(2)) both dilate the pulmonar y vasculature and improve oxygenation in adult respiratory distress syndrom e. We investigated whether similar effects would occur during early reperfu sion of a lung graft. Methods. Eighteen pigs underwent left lung transplantation. We measured blo od flow distribution, mean pulmonary artery pressure, PVR, and gas exchange in each lung separately. Animals were randomized into three groups to rece ive NO (10 ppm/30 minutes, 40 ppm/30 minutes), nebulized PGI(2) (25 mug/mL/ 30 minutes, 50 mug/mL/30 minutes), or no drugs (control). Results. In the transplanted lung, PVR was significantly higher than in the native lung. Pulmonary vascular resistance of the transplanted lung was lo wer in the NO and PGI(2) groups in comparison with the control group. Durin g the first hour of inhalation, NO decreased PVR more than PGI(2). Neither drug improved oxygenation in the graft. Conclusions. Nitric oxide and PGI(2) decreased PVR of the transplanted lung slightly, but the effect did not produce a normal pressure in pulmonary va sculature. (C) 2001 by The Society of Thoracic Surgeons.