Inhaled nitric oxide in persistent pulmonary hypertension of the newborn refractory to high-frequency ventilation

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.