INHALED NITRIC-OXIDE - CLINICAL-APPLICATIONS, INDICATIONS, AND TOXICOLOGY

Purpose: Although the analogy of nitric oxide (NO) to Endothelium-deri ved Relaxing Factor remains controversial, medical use of exogenous NO gas by inhalation has grown exponentially. This review presents the m echanisms of action of inhaled NO in pulmonary hypertension, hypoxaemi a, inflammation and oedema, as well as its therapeutic and diagnostic indications with emphasis on acute respiratory distress syndrome (ARDS ) and toxicology. Source: Two medical databases (Current Contents, Med line) were searched for citations containing the above-mentionned key words to December 1996. Moreover, many presentations in congresses suc h as 4th International Meeting of Biology of Nitric Oxide, 52nd and 53 rd Annual Meeting of Canadian Anaesthetists' Society or 10th Annual Me eting of European Association of Cardiothoracic Anaesthesiologists wer e used. Principal findings: inhaled NO is now recognized as an invalua ble tool in neonatal and paediatric critical care, and for heart/lung surgery. Other clinical applications in adults, such as chronic obstru ctive pulmonary disease and ARDS, require a cautious approach. The inh aled NO therapy is fairly inexpensive, but it would seem that it is no t indicated for everybody with regards to the paradigm of its efficien cy and potential toxicity. The recent discovery of its anti-inflammato ry and extrapulmonary effects open new horizons for future application s. Conclusion: Clinical use of inhaled NO was mostly reported in case series, properly designed clinical trials must now be performed to est ablish its real therapeutic role. These trials would permit adequate s election of the cardiopulmonary disorders, and subsequently the patien ts that would maximally benefit from inhaled NO therapy.