Increased mortality among extremely preterm infants with lower oxygen saturation target

Previous research has showed that the risk of retinopathy is lower in preterm infants exposed to reduced levels of oxygenation. With regard to adverse outcomes, the optimal target for oxygen saturation is not known.

A new study by NICHD Neonatal Research Network has compared two target ranges of oxygen saturation, 85-89% and 91-95%, among 1316 infants who were born before 28 weeks. Rates of the combined outcome of severe retinopathy or death did not differ significantly between groups. However, death before discharge was more frequent in the lower-saturation group (in 19.9% of infants vs. 16.2%; relative risk, 1.27; 95% CI, 1.01 to 1.60; P=0.04), whereas severe retinopathy among survivors occurred less often in this group (8.6% vs. 17.9%; relative risk, 0.52; 95% CI, 0.37 to 0.73; P<0.001).

The increased mortality is a major concern, since a lower target range of oxygen saturation is increasingly being advocated to prevent retinopathy of prematurity, the research group conclude.

Published online at www.nejm.org May 16, 2010 (10.1056/NEJMoa0911781)