Oximeters and Optimum Oxygen Saturation in Premature Infants

Targeting oxygen saturation below 90% is associated with increased mortality.

The optimum oxygenation for preterm infants remains controversial. The international Benefits of Oxygen Saturation Targeting (BOOST) II is one of four recent large trials to examine the effects of lower (85%–89%) versus higher (91%-95%) oxygen saturation targets in preterm infants (gestational age, 27 weeks).

In the first 1261 randomized infants, researchers discovered that the oximeters programmed to obtain the desired oxygen saturation resulted in overlapping target ranges because of a calibration problem. No difference in mortality between the two groups was discerned in these infants. Oximeters were adjusted to obtain the desired ranges for the subsequent 1187 infants. Interim analysis of these infants at a gestational age of 36 weeks revealed significantly higher mortality in the lower-target group than in the higher-target group (23.1% vs. 15.9%), and the study was closed. Among all infants, retinopathy of prematurity was less common in the lower-oxygenation group (10.6% vs. 13.5%, P=0.045) and necrotizing enterocolitis was more common (10.4% vs. 8.0%, P=0.04). All other outcomes were similar between the two groups.

CITATION(S):

The BOOST II United Kingdom, Australia, and New Zealand Collaborative Groups. Oxygen saturation and outcomes in preterm infants. N Engl J Med 2013 May 5; [e-pub ahead of print].