Inhaled Nitric Oxide in Preterm Neonates with Refractory Hypoxemia Associated to Oligohydramnios

Therapy with inhaled nitric oxide (iNO) is effective in the management of pulmonary hypertension and severe hypoxemia. However, these benefits have not been demonstrated in preterm infants (<34 weeks). The objective of this report is to present the experience of eight cases of preterm neonates with respiratory distress syndrome (RDS) and refractory hypoxemia, with oligohydramnios history.

We evaluated the clinical feature of 8 preterm neonates with severe hypoxemia who had maternal antecedents of oligoamnios, mainly due to premature rupture of membranes. They were treated with conventional management, with poor clinical response. Therefore, these neonates were treated with iNO, as a rescue strategy. iNO has been used with a dosage of 5 - 10 ppm. An echocardiogram was performed to determine the presence of structural malformations or persistent ductus arteriosus.

All the infants showed improvement in oxygenation. The neonates had signs of low flow pulmonary, confirmed by echocardiogram. Five preterm infants survived without complications associated with the therapy. Two died from pulmonary bleeding secondary to ductus arteriosus and another for pneumothorax.

iNO therapy can be useful in a subgroup of preterm infants with a high risk of death secondary to hypoxemia. Although this report is based on a small number of cases, it follows the directions of other studies that suggest that iNO therapy can benefit preterm neonates, particularly those exposed to oligohydramnios.