Milrinone Versus Sildenafil in Treatment of Neonatal Persistent Pulmonary Hypertension: A Randomized Control Trial

Persistent pulmonary hypertension of the newborn (PPHN) is a condition caused by failure of pulmonary vascular adaptation at birth, resulting in severe hypoxia. Several therapeutic modalities are being tried in developing countries where established therapies (inhaled nitric oxide and extracorporeal membrane oxygenation) are widely unavailable. This study aimed to assess the efficacy of milrinone versus sildenafil as available alternative therapeutics in treating PPHN. Forty neonates (>34 weeks) admitted to neonatal intensive care units with evidence of PPHN were randomly allocated to receive either oral sildenafil (0.5-2 mg/kg/6 hours) or intravenous milrinone (0.25-0.75 mic/kg/min). Primary outcomes included improvements in systolic pulmonary artery pressure and oxygen saturation index (OSI) at 24 and 48 hours after treatment. Secondary outcomes included the duration of hospitalization and mechanical ventilation. The ClinicalTrials identifier is NCT04391478. Both groups showed significant improvement in the post-treatment hemodynamic variables compared with pretreatment levels ( P < 0.05 for all parameters). Systolic pulmonary artery pressure and OSI values significantly improved in both study groups compared with baseline ( P < 0.001). The 24-hour and 48-hour post-treatment OSI values were much lower in the milrinone group than those in the sildenafil group ( P < 0.05). The length of hospital stay was significantly shorter in the milrinone group than that in the sildenafil group ( P < 0.05). There were no significant differences in the duration of mechanical ventilation, incidence of intracranial hemorrhage and pulmonary hemorrhage, or mortality between the 2 groups ( P > 0.05). In conclusion, milrinone and sildenafil are effective and well-tolerated in neonates with PPHN, particularly when inhaled nitric oxide and extracorporeal membrane oxygenation are not available. Milrinone is superior to sildenafil in improving oxygenation without lowering blood pressure parameters.