PRELIMINARY EXPERIENCE WITH INHALED NITRIC-OXIDE FOR ACUTE PULMONARY-HYPERTENSION AFTER HEART-TRANSPLANTATION

Background: Substantial interest has developed in the physiologic and therapeutic role of nitric oxide in the last few years. In patients wi th pulmonary hypertension it appears to be a useful selective pulmonar y vasodilator; however, many issues of both staff and patient safety r emain unanswered. Methods: This study examines further safety issues a nd also presents preliminary clinical experience in patients after ort hotopic heart transplantation with pulmonary hypertension and right-si ded ventricular failure. Results: Atmospheric levels of nitric oxide a nd nitrogen dioxide are 100 times less than occupational health standa rds. When nitric oxide is used at 70 parts per million in the presence of a fraction of inspired oxygen greater than 0.60, nitrogen dioxide levels in the circuit exceed the published short-term exposure limit o f the American Conference of Government Industrial Hygienists of 5 par ts per million. Conclusion: Staff safety appears confirmed, but despit e encouraging clinical results, further longer term safety and efficac y studies are indicated.