High or low oxygen saturation for the preterm baby.

The observational study by Tin et al 1 of outcome related to oxygen saturation in infants of less than 28 weeks gestation from a number of disparate units in the Northern Region shows results that are interesting, but only from the point of hypothesis generation. Monitoring of oxygen saturation is simple but not without problems. 3 Setting aside whether preterm infants requiring additional oxygen should be managed by monitoring oxygen saturation or oxygen partial pressure, does this study have any implications for management of such infants in the future? Is there any other corroborative evidence that the outcome of infants managed at lower saturations do better in terms of neurodevelopmental, respiratory, growth, or visual outcome? The STOP-ROP study was designed to test the hypothesis that supplemental oxygen would reduce progression of retinopathy of prematurity (ROP). Infants with prethreshold ROP were randomised to either high (96–99%) or low (89–94%) saturation groups. There were no significant differences in the visual outcomes. Supplemental oxygen, however, increased the risk of adverse respiratory events including pneumonia and chronic lung disease with significant need for extra oxygen, diuretic therapy, and hospitalisation at 3 months corrected age. There was no diVerence in growth or neuromotor development. The respiratory morbidity in this study was not the primary study outcome and we must await the “Benefits of Oxygen Saturation Targeting Trial” from Australia to confirm or refute these findings (D Henderson-Smart, personal communication). More pertinent may be work in an animal model of ROP indicating that management in lower oxygen (reducing the mean partial pressure of oxygen by 2 kPa to the lower end of the “safe” range) reduces the incidence and severity of ROP. Preliminary data from this model also show that apoptotic proteins (compared with antiapoptotic proteins) in the brain are increased with higher oxygen. Preterm babies must be given adequate oxygen, but possibly our reference to well term infants is inappropriate— infants with relatively low saturations because of cyanotic heart disease are not automatically compromised with regard to either growth or neurodevelopment. NEIL MCINTOSH Child Life and Health University of Edinburgh Edinburgh EH9 1UW, Scotland [email protected]