[Sildenafil and nitric oxide inhalation in neonatal pulmonary hypertension. Three case reports]

Neonatal persistent pulmonary hypertension (NPPH) is characterised by persistently high pulmonary vascular resistance (PVR). Sildenafil has recently been suggested as an alternative to or an associative therapy with inhaled nitric oxide (iNO) to reduce mortality (10-40%) and morbidity (major neurologic disabilities among surviving newborns remains approximately 15-60%). The objective is to report three cases of NPPH treated with sildenafil in association of iNO.

Echocardiography examination of three newborn babies with respiratory distress syndrome and a gestational age between 33 and 39 weeks revealed pulmonary hypertension following early onset sepsis. Synchronized intermittent mandatory ventilation (SIMV) and surfactant therapy had no effect on oxygen saturation (SatO2) and oxygen alveolar-arterial difference (AaDO2). High frequency oscillatory ventilation (HFOV) and iNO therapy proved to be equally ineffective. Oral sildenafil was administered at 2 mg/Kg/6 hs. A gradual but significant improvement in oxygenation was achieved and a reduction in AaDO2 along with oxygenation index (OI) and pulmonary arterial pressure (PAP) was observed in the first 6-10 hrs after administration of sildenafil. The therapy was maintained for 36-48 hrs with total success.

A beneficial pulmonary vasodilator effect was obtained in treating NPPH with sildenafil where conventional methods had failed. Sildenafil used in association with iNO reduces the duration of treatment, the quantity of iNO normally required and the associated toxic effects. A multicentric, randomized trial could be useful in demonstrating the safety, efficacy, doses and forms of administration of sildenafil.