Comparison of the Efficacy of Milrinone Injection versus Milrinone Plus Oral Sildenafil in Newborns with Pulmonary Arterial Hypertension

pulmonary hypertension is a serious problem in newborns, which is associated with increased pulmonary vascular resistance, leading to right-to-left extrapulmonary shunt and impaired lung oxygenation and severe hypoxemia in the neonatal period. The purpose of this study was to evaluate the effect of oral Sildenafil with intravenous Milrinone on the treatment of pulmonary hypertension in newborns.

The statistical population of this study consisted of all term and late preterm neonates admitted to NICU wards of Afzalipour Hospital in Kerman. A total of 80 neonates were included and divided into the intervention group (intravenous Milrinone with oral Sildenafil), and control group (intravenous Milrinone alone). The related criteria for increasing pulmonary artery pressure, including mean pulmonary artery pressure (mean PAP), Tricuspid valve regurgitation (TR), pulmonary artery diameter (PAD) and right ventricular systolic function by measuring TAPSE (Tricuspid annular presystolic excursion) were assessed by echocardiography in the first 24hours after birth and 72 hours after the intervention in all patients. Data analysis was done through SPSS24 software.

The mechanical ventilation time in the group treated with oral Sildenafil (2.5 days) was significantly (p <0.0001) shorter than that in the control group (10.5 days). Also, the hospital stay in NICU in the intervention group (11.3 days) was significantly (p <0.0001) shorter than that in the control group (20.2 days). Pulmonary artery pressure showed a significant decrease in the intervention group 72 hours after adding Sildenafil compared to the control group. The mean difference of TR gradient was significantly (P<0.0001) higher in the intervention group (59) than in the control group (22). The mean PAP difference was also significantly (P= 0.005) higher in the intervention group (47.7 mmHg) compared to the control group (33.3 mmHg). Besides the TAPSE difference was significantly (P = 0.009) lower in the intervention group (33.7) than in the control group (47.2). There was no significant difference in the PAD (Pulmonary artery diameter) between the two groups (P = 0.312). Also, there was no significant difference in mortality rate between the intervention group (3.7%) and control group (5%).

The results of our study showed that the addition of oral Sildenafil to intravenous Milrinone was associated with better therapeutic outcomes in the treatment of neonatal pulmonary hypertension. Conducting similar studies is necessary for the final proof of this issue.