Inhaled nitric oxide in patients with normal and increased pulmonary vascular resistance after cardiac surgery

We studied the haemodynamic effects of inhaled nitric oxide40 p.p.m. in two groups of patients after cardiac surgery (mitralvalve surgery or coronary artery bypass grafting). Nitric oxidecaused a significant reduction in pulmonary vascular resistanceafter mitral valve surgery in patients who had pre-existingpulmonary hypertension, but no change in haemodynamic statein the coronary artery bypass group of patients, who had normalpulmonary arterial pressures.