Purpose: To review the pulmonary and systemic effects of endogenous nitric oxide and inhaled nitric oxide administered to patients.
Source: A systematic search for experimental data, human case reports, and randomized clinical trials since 1980, the year of discovery of endothelium-derived relaxing factor.
Principal findings: Nitric oxide has pulmonary and systemic effects. Inhaled nitric oxide not only causes selective pulmonary vasodilation but also results in pulmonary vasoconstriction of the vessels perfusing non-ventilated alveolae. The systemic effects of inhaled nitric oxide, which include modulation of the distribution of systemic blood flow, increase in renal output, interaction with coagulation, fibrinolysis and platelet functions, alteration of the inflammatory response, are described and the mechanisms of nitric oxide transport are explained. The possible toxicity of inhaled nitric oxide is also discussed.
Conclusion: The multiple effects of inhaled nitric oxide support its role as a pulmonary and extra-pulmonary medication.