Background. Nitric oxide was used as an important selective vasodilator in the treatment of acute respiratory failure accompanied with high pulmonary resistance in children and adults since late 80’s. Methods and Results. Paper includes remarks about nitric oxide physiology in organism. Group of 33 patients is presented (group I 26 newborns, group II 7 children) in which selective pulmonary vasodilation with nitric oxide was used. According to response to NO subject were classified into subgroups of responders, non-responders. In evaluation of oxygenation status OI (oxygenation index), A-a DO2 (alveoloarterial difference) and paO2/FiO2 were used. Conclusions. Significant differences of above mentioned values were revealed between responders and non-responders in group I (newborns). Significant differences were not revealed in group II (children). Results are in accordance with other papers.

        Key words: inhaled nitric oxide, respiratory failure.