Effect of Optimizing Oxygen Saturation Targets on the Incidence of Retinopathy of Prematurity in a Quaternary NICU

Abstract

Introduction: Retinopathy of prematurity (ROP) is a multifactorial disease and a preventable cause of blindness in childhood. Hyperoxia and hypoxia can cause retinal neovascularization resulting in retinal detachment and blindness if left untreated. Besides oxygen treatment, other reasons for ROP development are well known. We prospectively adopt various strategies to keep oxygen saturation (SpO2) within targets, between 91 and 95% for those on supplemental oxygen. By adapting this, we postulated that the incidence of severe ROP might be reduced. Methods: 2018–2019 provided pre-intervention and 2020 post-intervention data for the project. For all babies (≤32 weeks, ≤1,500 g with FiO2 >0.21), target SpO2 between 91 and 95% was measured as a percentage of time spent within and outside target SpO2 during 1–4 weeks of life. Results: 112 and 60 preterm neonates were screened for ROP during the pre- and post-intervention phase. Twenty neonates (18.3%) during pre-intervention and 16 (26.7%) in the post-intervention phase developed severe ROP requiring treatment. Despite a statistically significant increase of 10 percent points in time spent within target SpO2 (91–95%) in the post-intervention phase (p < 0.05), the incidence of severe ROP did not decline. Using a multivariate model, odds of ROP development decreased with gestational age (25%) while increasing with PDA requiring treatment (4.33 times) and glucose ≥10 mg/dL (4.15 times), considering one variable at a time, keeping others constant. Conclusion: Our QI project showed successful attainment of maximum time; the SpO2 remained within targets during supplemental oxygen; however, the incidence of severe ROP had not declined. Factors other than SpO2 might be responsible for a high incidence of ROP in our neonatal intensive care unit.

Keywords

• retinopathy of prematurity
• oxygen
• oxygen saturation