Abstract 14185: Targeting Lower Oxygen Saturation Parameters in Premature Infants Does Not Increase Incidence of Pulmonary Hypertension in the Neonatal Intensive Care Unit

Abstract

Introduction: Lower oxygen saturation targets in preterm infants have been associated with decreased incidence of bronchopulmonary dysplasia (BPD) but increased risk of pulmonary hypertension (PH). Studies have shown that targets of <90% are associated with higher incidence of PH, however data on the optimal saturation target >90% are lacking. In this study, we compared the rate of BPD and PH in two cohorts with saturation targets of 94-98% and 92-97%. We hypothesized that BPD rate would be lower and PH rate would be unchanged at the lower saturation target. Methods: We performed a retrospective cohort study comparing PH and BPD rates among two cohorts of infants born at ≤32 weeks gestation at Brigham and Women’s Hospital: cohort 1 with saturation target of 94-98% (n = 129, July 2017-July 2018), cohort 2 with saturation target of 92-97% (n = 124, July 2018-July 2019). PH was defined by echocardiographic evidence of systolic septal flattening or right ventricular pressure ≥35 mmHg (estimated by tricuspid regurgitant jet velocity or shunt velocity) at gestational age (GA) ≥36 weeks. Comparisons between groups were carried out by Chi-square test, t-test, and multivariable logistic regression. Results: Subjects had a GA of 23-32 weeks; 46% were female. Groups did not differ with respect to GA, sex, or birth weight. There was no difference in rate of PH (2.4% vs. 4.2%, p = 0.12) or BPD (25% vs. 20%, p = 0.31) between cohort 1 and cohort 2. Other clinical parameters were not different between groups, including presence of patent ductus arteriosus, presence of atrial septal defect, use of diuretics, or use of steroids. After controlling for GA, birth weight, sex, and diagnosis of BPD using logistic regression, there was no difference in rate of PH between groups (p = 0.47), but there was a positive association of BPD with PH (OR 3.45; 95% CI, 1.18-10.09; p = 0.02). Conclusions: A lower oxygen saturation target was not associated with a higher rate of PH or lower rate of BPD in preterm infants. The overall rate of PH was much lower than rates previously reported at saturation targets <90%. Given our low incidence of PH, and the lack of a significant difference in rate of PH between groups, a saturation target of 92-97% may be safe while also minimizing need for supplemental oxygen in this population.