Introduction
A wide range of life-threatening lung diseases are characterized by 		 compromised capacity of the lung to match ventilation and perfusion. This 		 results in poor oxygenation of arterial blood and significant hypoxemia. 		 Pulmonary hypertension and poor myocardial function often play a role in the 		 pathophysiology of pulmonary disease [1]. Several 		 vasodilator agents have been shown to decrease pulmonary vascular resistance, 		 but their use was limited by concomitant decreases in systemic vascular 		 resistance and worsening of intrapulmonary shunt [2]. 		 Recently, selective pulmonary vasodilation with inhalational nitric oxide (INO) 		 has been demonstrated in both clinical and experimental settings [3,4,5].
This pilot study was conducted to evaluate the effect of INO in the 		 management of neonates with severe persistent pulmonary hypertension refractory 		 to high-frequency oscillatory ventilation.