The question of which oxygen-saturation level is best for very premature infants remains open after the publication of two studies over the weekend. Commentators suggest that levels under 90% should be avoided, however.
Researchers in the BOOST II study (published in the New England Journal of Medicine) report outcomes at hospital discharge for some 2400 infants randomized to lower (85 to 89%) or higher (91 to 95%) saturation levels. Interpretation is muddied somewhat by the fact that the oximeters had a measurement flaw that wasn’t discovered until halfway through the study. Among infants measured with corrected oximeters, mortality was higher for those receiving lower oxygen saturation (23% vs. 16%). Retinopathy was lower with lower saturation.
In JAMA, COT study researchers found no significant differences in the rates of mortality or retinopathy by 18 months in some 1200 infants similarly studied.
Commentators say the best interim course would be to target saturation levels between 90% and 95%, realizing the dangers of retinopathy.