Those who resuscitate full term or preterm infants are finding more and more studies that attempt to determine whether room air or a higher initial fraction of inspired oxygen (FiO2) is the approach of choice. Unfortunately each study that reaches a conclusion may carry with it issues of sample size or other limitations that prevent generalization of the conclusions as standard of care. It is for that reason that the International Liaison Committee on Resuscitation (ILCOR) decided to provide us with two systematic reviews and meta-analyses by Welsford et al. –one focused on resuscitation using room air or higher FiO2 for term newborns (10.1542/peds.2018-1825) and the other on the ideal initial FiO2 for preterm newborns in the delivery room (10.1542/peds.2018-1828). The term newborn review looked at 12 studies involving randomized or quasi-randomized controlled trials and follow-up reports involving 2,164 patients, and found room air showed a 27% relative reduction in short-term mortality relative to FiO2 of 1.0 for term and late preterm resuscitation. The second study identified 16 studies (ten randomized controlled trials, two follow-ups and four observational studies that totaled 5,697 patients and found no significant benefits or risks of starting with lower compared to higher FiO2 for short-term or long-term mortality or other key preterm morbidities and concluded that the ideal FiO2 for preterms remains a mystery although some oxygen supplementation is recommended.
So what do we do with these two long-awaited reviews, one appearing more conclusive than the other regarding favoring a lower versus higher FiO2 (i.e. the review on late preterm or term infants). To help make sense of both studies, we asked neonatologist Dr. Roger Soll from the University of Vermont and the Vermont Oxford Network to share his thoughts in an accompanying commentary (10.1542/peds.2018-3365). He notes how ILCOR not only reviews these studies but grades their strength as well on domains such as imprecision, generalizability, inconsistency and various biases which in turn reduces the certainty of the evidence as provided in the meta-analyses. While these reviews are fascinating to read and consolidate a lot of research into these two systematic overviews, they may not get us to the state of the art guidelines that tell us what is best oxygenation strategy for resuscitating newborns term or preterm or so Dr. Soll points out. He notes that the evidence, though well researched from a systematic methodology approach, still leaves us with uncertainty and calls for even better studies that will help us find the certainty that the current studies reviewed in these two papers lack. Do you agree with Dr. Soll’s perspective or feel these reviews can help shape more definitive practice guidelines? We hope you will share your thoughts by responding to this blog, posting a comment on our website with these reviews, or simply sharing your opinion on our Facebook or Twitter sites.