AIMTo determine if infants who had become dependent on inhaled nitric oxide treatment could be successfully weaned off it if FIO₂ was increased briefly during withdrawal.
METHODSSixteen infants admitted for conditions associated with increased pulmonary vascular resistance responded well to inhaled nitric oxide treatment with a significant increase in PaO₂ (maximum inhaled nitric oxide given 25 ppm). Weaning from inhaled nitric oxide in 5 ppm decrements was initiated once the FIO₂ requirement was less than 0.5. When patients were stable on 5 ppm of inhaled nitric oxide, the gas was then discontinued. If a patient showed inhaled nitric oxide dependencethat is, oxygen saturation fell by more than 10% or below 85%inhaled nitric oxide was reinstated at 5 ppm and the patient allowed to stabilise for 30 minutes. At this time, FIO₂ was increased by 0.40 and weaning from inhaled nitric oxide was attempted again.
RESULTSNine infants were successfully weaned on the first attempt. The seven infants who failed the initial trial were all successfully weaned following the increase in FIO₂. After successful weaning, FIO₂ was returned to the pre-weaning level in mean 148(SD 51) minutes and inhaled nitric oxide was never reinstated.
CONCLUSIONInfants showing inhaled nitric oxide dependency can be successfully weaned by increasing FIO₂ transiently.

Keywords: inhaled nitric oxide; weaning; ECMO.