Air rather than 100% oxygen for babies requiring ventilation after delivery could reduce infant mortality

Provision of air rather than 100% oxygen for babies requiring ventilation after delivery could reduce infant mortality, suggests a study in this week’s issue of THE LANCET. The finding is counter to the long-held belief that 100% oxygen is better than air for babies requiring ventilation in the first few minutes of life.

Between 5–10% of newborn babies require assistance with breathing after delivery. International consensus statements for resuscitation of newborn infants recommend provision of 100% oxygen if assisted ventilation is required. However, there are concerns that 100% oxygen reduces cerebral blood flow in newborn babies.

Peter Davis (Royal Women’s Hospital/University of Melbourne, Australia) and colleagues did a systematic review and meta-analysis of 5 trials (totalling around 1300 newborn infants) that compared resuscitation with air versus 100% oxygen. Babies from the five studies were generally born close to full term (average 38 weeks), were predominantly from developing countries, and were moderately asphyxiated.

Although no individual study reported a significant difference in death rate, when the trials were combined in a meta-analysis, 5% fewer babies given air died compared with babies given 100% oxygen. No differences were found in long-term neurological outcomes, though the only study attempting longer-term follow-up was found to have methodological weaknesses.

Dr Davis comments: “One death would be prevented for every 20 babies resuscitated with air rather than 100% oxygen. For term and near-term infants, we can reasonably conclude that air should be used initially, with oxygen as backup if initial resuscitation fails. The effect of intermediate concentrations of oxygen at resuscitation needs to be investigated. Future trials should include and stratify for premature infants”.

In an accompanying commentary (p 1293), Georg Hansmann (Stanford University, USA) concludes: “The evidence for mortality reduction with air is striking and will have widespread impact on the management and outcome of depressed newborn infants. At the upcoming Evidence Evaluation Conference in 2005, experts might attend to the new data, alter the guidelines for neonatal resuscitation carefully, set new goals, and make suggestions about how to achieve, maintain, and monitor normoxaemia [normal oxygen saturation] in depressed infants at birth”.