Association of Oxygen Target and Growth Status With Increased Mortality in Small for Gestational Age Infants: Further Analysis of the Surfactant, Positive Pressure and Pulse Oximetry Randomized Trial
This post hoc study assesses whether there is an association between oxygen target and growth status. The Eunice Kennedy Shriver National Institute of Child Health and Human Development Surfactant, Positive Pressure and Pulse Oximetry Randomized Trial (SUPPORT)1 compared the effect of oxygen saturation targets on retinopathy of prematurity or death among infants born at 24 to 27 weeks’ gestational age. One thousand three hundred sixteen infants were randomized to lower (85%-89%) vs higher (91%-95%) target oxygen saturation. Rates of severe retinopathy of prematurity or death were not different (28.3% and 32.1%, respectively; relative risk with lower target, 0.90; 95% CI, 0.76-1.06; P = .21). Lower oxygen targets reduced severe retinopathy of prematurity among survivors (8.6% vs 17.9%; relative risk, 0.52; 95% CI, 0.37-0.73; P < .001). However, an unanticipated and unexplained finding was increased mortality in the lower saturation group (19.9% vs 16.2%; relative risk, 1.27; 95% CI, 1.01-1.60; P = .04). The study included neurodevelopmental assessment at 2 years of age; at that assessment we noted a disproportionate loss of small for gestational age (SGA) infants. This observation promoted us to assess whether there was an interaction between oxygen target group and growth status.