One-year continuous inhaled nitric oxide for primary pulmonary hypertension.

We describe a case of long-term administration of nitric oxide (NO) in a 32-year-old man who was admitted with exertional dyspnea and anasarca. A diagnosis of primary pulmonary hypertension was made. An acute vasodilator trial with inhaled NO showed a 5% reduction of the mean pulmonary artery pressure. Long-term NO inhalation therapy was initiated. Twenty days later, the dyspnea improved, the anasarca resolved, and the PaO(2) level increased. After 12 months of NO therapy, the patient remained stable and no signs of toxicity or tachyphylaxis were observed. To our knowledge, this is the first report of 1 year of continuously inhaled NO in an adult patient with primary pulmonary hypertension. These findings suggest that prolonged NO therapy might be an effective alternative, at a lower cost, to the continuous IV infusion of epoprostenol.