This new publication is not a complete systematic review, but is a review of the history, design and outcomes of the oxygen saturation targeting trials, and of the early stopping of 2 trials. Stenson BJ. Oxygen Saturation Targets for Extremely Preterm Infants after the NeOProM Trials. Neonatology. 2016;109(4):352-8. It includes a meta-analysis of the primary outcomes of the trials, including mortality, disability, and certain of the components of those outcomes. The only difference between the groups was in mortality, which led to a significant difference in the combined primary outcome, of death or disability at 18 to 24 months. In case you can’t get access to the full text, here are 2 small parts of the publication, the mortality data, showing a 16% increase in mortality with lower saturations, and no heterogeneity between trials:
Ben Stenson discusses the impacts of the changes in oximeter calibration algorithm, and shows the before and after mortality data for those studies where the algorithm was changed part way through :
Perhaps because the separation between the saturation ranges was a little greater after the change, that is where the mortality difference is seen, in all the 3 trials where it was changed. There is also an increase in NEC (relative risk of 1.25), which is at least one of the causes of death that seems to have increased with the lower saturations.
One might ask why the SUPPORT trial, with only the old algorithm, showed a difference in mortality. I think it is possible that that was because of the antenatal consent and enrollment at birth, it may be that aiming for lower saturations is even more hazardous if you start the lower saturations immediately during the transition period.
Nevertheless the first graph shows that all of the data together, including both algorithms and all the trials, there is an increase in mortality.
The final conclusion is:
In trials conducted in a developed world setting with continuous SpO2 monitoring and protocols for screening for and treating ROP, targeting SpO2 below 90% in extremely preterm infants increased mortality and did not reduce the risk of blindness or other disabilities and cannot be recommended.