Mortality Risk Factors and Survival Outcomes in Infants with Persistent Pulmonary Hypertension of the Newborn.

Background/

Objectives

Persistent pulmonary hypertension of the newborn (PPHN) is characterized by increased pulmonary vascular resistance, resulting in severe hypoxemia. This study determined the factors associated with increased risk of mortality and survival rate in infants with PPHN.

Methods

This retrospective study was conducted between 2010 and 2023. The risk factors for mortality were assessed by Cox's proportional hazard models, and the Kaplan-Meier survival curve was used to analyze the survival rates.

Results

This study included 233 neonates with PPHN. Gestational age (GA) less than 28 weeks (adjusted hazard ratio [AHR] = 5.46, 95% confidence interval [CI]: 2.25-13.24, p < 0.001), Small for gestational age (SGA) (AHR = 2.93, 95% confidence interval [CI]: 1.24-6.92, p = 0.026), acute kidney injury (AKI) (AHR = 2.48, 95% CI: 1.27-4.84, p = 0.01), pneumothorax (AHR = 3.03, 95% confidence interval [CI]: 1.48-6.21, p = 0.003), vasoactive-inotropic score (VIS) at 24 h of age (AHR = 1.0026, 95% confidence interval [CI]: 1.0004-1.005, p = 0.026), and score for neonatal acute physiology II (SNAP-II) ≥ 43 (AHR = 4.03, 95% CI: 1.66-9.77, p = 0.005) were associated with an increased risk of mortality. The overall survival rate was 82.4%; it rose from 63.8% to 87.1% after inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation (ECMO) were introduced (p < 0.001). The cumulative survival rates at the end of the 30 days were 62.1% (95% CI: 49.0-78.7) in the Pre-iNO era and 87.5% (95% CI: 82.7-92.6) in the Post-iNO/ECMO era, respectively (p < 0.001).

Conclusions

GA less than 28 weeks, SGA, AKI, pneumothorax, high VIS and SNAP-II scores were associated with mortality in infants with PPHN. The improvement in the survival rate was related to the provision of advanced care, including iNO and ECMO therapy.