Risk Factors and Mortality in Newborns with Persistent Pulmonary Hypertension: A Six-Year Single-Center Experience.

Objectives: Persistent pulmonary hypertension (PPHT) of the newborn is a disorder of circulatory transition resulting in high pulmonary vascular resistance with extrapulmonary right-to-left shunts causing hypoxemia. In this study, our aim was to evaluate the risk factors, administered treatments, and mortality of patients followed in our neonatal intensive care unit (NICU) due to PPHT over the past six years. Methods: Patients diagnosed with PPHT and followed in the NICU between January 2017 and November 2022 were included in the study. The sociodemographic characteristics, diagnoses that could lead to pulmonary hypertension, the presence of congenital anomalies, the duration of respiratory support treatment and hospital follow-up, treatments administered for PPHT, and mortality rates were evaluated. Results: Out of 21 patients diagnosed with persistent pulmonary hypertension, 9 of them (42.9%) were male. The mean gestational age of the patients was 37.6±3.7 weeks, and their birth weight was 3006±819grams. The APGAR scores at 1 and 5 minutes were 4(2-7) and 6(3-8), respectively. Risk factors during the antenatal period included fetal distress (38.1%), oligohydramnios (23.8%), intrauterine growth restriction (23.8%), gestational diabetes (14.3%), preeclampsia (4.8%), and chorioamnionitis (4.8%). The median duration of invasive mechanical ventilation for cases requiring respiratory support was 20.1 days, while the median duration of non-invasive ventilation was 3.7 days. Patients with a diagnosis of persistent pulmonary hypertension were treated with inhaled nitric oxide (iNO) in 76.2% of cases, milrinone in 66.7% of cases, sildenafil in 52.4% of cases, and iloprost in 14.3% of cases. The length of hospital stay for patients was 38.4 days, and 9 (42.9%) patients died. The patients who died had severe PPHT along with fetal inflammatory response syndrome (FIRS), congenital heart disease, pulmonary hypoplasia, pneumothorax, hypoxic-ischemic encephalopathy (HIE), and congenital anomalies. Conclusion: Persistent pulmonary hypertension, characterized by severe hypoxemia, is a neonatal emergency that necessitates early intervention, effective treatment of the underlying cause to prevent potential short-term and long-term morbidities and mortality. Effective treatment of the underlying cause in patients diagnosed with PPHT could reduce morbidity and mortality. It is inevitable to avoid the loss of patients with major abnormalities, severe comorbidities, and unpreventable organ dysfunctions.