Oxygen saturation target range for extremely preterm infants: a systematic review and meta-analysis

Area of Science:

• Neonatal Medicine
• Pediatric Critical Care
• Respiratory Physiology

Background:

• Optimal oxygen saturation (SpO2) targets for extremely preterm infants remain undefined.
• Current clinical practices vary, lacking definitive evidence for specific SpO2 ranges.

Purpose of the Study:

• To systematically review existing evidence on the impact of restricted versus liberal oxygen exposure on morbidity and mortality in extremely preterm infants.
• To synthesize findings from randomized trials to inform clinical guidelines.

Main Methods:

• A comprehensive search of multiple databases (MEDLINE, PubMed, CENTRAL, CINAHL) and conference abstracts was conducted.
• Included published randomized trials comparing restricted (SpO2 85%-89%) with liberal (SpO2 91%-95%) oxygen exposure in infants born before 28 weeks' gestation.
• Meta-analyses used random-effects models, with study quality assessed by the Cochrane risk-of-bias tool and evidence certainty by GRADEpro.

Main Results:

• Five trials were synthesized, with a composite outcome of death/disability at 18-24 months. No significant difference was found in death/disability before 24 months (RR 1.02).
• Mortality before hospital discharge was higher in the restricted oxygen group (RR 1.18), but overall mortality before 24 months was not significantly different (RR 1.13).
• Necrotizing enterocolitis rates were higher with restricted oxygen (RR 1.24), while bronchopulmonary dysplasia, neurodevelopmental outcomes, hearing loss, and retinopathy of prematurity showed no significant differences between groups. Evidence quality was moderate to low.

Conclusions:

• Liberal oxygen targets were associated with lower in-hospital mortality but with low-certainty evidence. The incidence of necrotizing enterocolitis was reduced in the liberal oxygen group.
• No significant differences were observed in death or disability at 24 months, bronchopulmonary dysplasia, retinopathy of prematurity, neurodevelopmental outcomes, or hearing loss.
• The findings highlight a trade-off between early mortality and other morbidities, underscoring the uncertainty surrounding optimal oxygen management for extremely preterm infants.