[Inhalation therapy with nitric oxide--an evaluation of a dosage system and clinical examples]

In 1987 it was discovered that nitric oxide is a very potent vasodilator and in fact a natural mediator for vasodilatation. The effects of inhalation of nitric oxide on pulmonary vascular resistance were described in 1988 and a new therapeutic possibility for artificially ventilated patients with pulmonary hypertension has arisen. However, the administration of nitric oxide has to be performed with high accuracy and without reaching toxic levels of nitrogendioxide. We have evaluated a system using conventional air and oxygen rotameters for administration of nitric oxide via a ventilator. A comparison of the chemiluminescence technique with a technique based on fuel cells was also performed. With the system it was possible to administer nitric oxide with high accuracy within the range of 10-60 ppm without exceeding values for nitrogendioxide above 0.4 ppm. The analysis of nitric oxide and nitrogendioxide based on electrochemical cells proved to be comparable with the chemiluminescence technique within the same range. Nitric oxide inhalation was used in six patients with severe hypoxia and seemed to have a favorable effect on most of the patients.