[Inhaled nitric oxide: therapeutic applications in cardiac surgery]

The occurrence of right ventricular failure secondary to pulmonary arterial hypertension is a major postoperative complication of cardiac surgery in children and adults. The selective pulmonary vasodilation produced by inhaled nitric oxide (NO) constitutes a fundamental therapeutic advance in the management of this pathology. NO binds immediately with haemoglobin, resulting in its immediate inactivation. This results in perfect maintenance of systemic and coronary blood pressures. A first study performed in 1989 after mitral valve replacement for mitral stenosis with pulmonary hypertension and clinical trials after surgical correction for congenital heart disease and heart transplantation with pulmonary hypertension suggested the efficacy and safety of 20 to 40 ppm NO concentrations in these indications. Potential toxicity of NO (NO2 production by oxidation, methaemoglobin formation) leads to caution with its use. Monitoring of NO concentration and methaemoglobin production is recommended, especially in new-borns.