Background:
This study was designed to evaluate the effect of nitric oxide 				(NO) on the management of neonates with severe persistent pulmonary 				hypertension refractory to high-frequency oscillatory ventilation.

Methods:
The birth weight and the gestational age of infants 				were 3125.5 ± 794 g (mean ± SD) and 39 ± 2.4 weeks, respectively. All 				neonates were ventilated for an average of 137.5 min (range 90-180 min) prior to 				NO therapy. The mean oxygenation index (OI) of all neonates prior to NO was 				46.3 ± 5 (mean ± SEM). NO was initially administered at 20 parts per 				million (ppm) for at least 2 h and increased gradually by 2 ppm to a maximum of 				80 ppm.

Results:
Eighteen infants (75%) responded and six (25%) did not respond to 				the treatment. Three neonates died in the responding group, while all the 				non-responders died (P = 0.0001). The survival rate was 62.5% among all 				neonates. NO significantly decreased OI (P < 0.0001) and improved 				the arterial/alveolar (a/A) oxygen ratio (P < 0.0001) within the 				first 2 h of NO therapy in 61.1% of the responders. However, the OI and the a/A 				oxygen ratio remained almost the same throughout the treatment in the 				non-responders and the non-survivors.

Conclusion:
Inhaled NO at 20 ppm, following adequate ventilation for 2 h without 				significant response, could be used to identify the majority of the 				non-responders in order to seek other alternatives.