INHALED NITRIC-OXIDE THERAPY

Objective: To review the basic science, physiology, toxicity, and deli very of inhaled nitric oxide (NO). Design: A literature review of inha led NO is presented, and a brief discussion of current clinical applic ations is included. Results: Inhaled NO is a new investigational drug used for selective vasodilation of the pulmonary vasculature, It mimic s the effects of endogenously produced endothelium-derived relaxing fa ctor, In addition to selective pulmonary vasodilation, inhaled NO can improve hypoxemia by improving ventilation-perfusion relationships wit hin the lung, The doses of inhaled NO that produce improvements in oxy genation are lower than those needed to produce maximal vasodilation. Inhaled NO is being used in the intensive-care unit to treat criticall y ill patients with pulmonary hypertension or hypoxemia associated wit h ventilation-perfusion imbalance. It is also being used in the cardia c catheterization laboratory as a diagnostic tool, Few adverse effects have been associated with the use of inhaled NO. Conclusion: Despite a lack of randomized, controlled studies that show improved outcome in comparison with traditional treatments, inhaled NO seems to be an eff ective new therapy for patients with pulmonary vasospasm or hypoxemia associated with ventilation-perfusion imbalance. It may also prove to be a valuable diagnostic tool in the cardiac catheterization laborator y.