Abstract

Background: Oxygen saturation (Spo₂) monitors are commonly used to determine the need for supplemental oxygen. We aimed to describe the range of arterial oxygen tensions (Pao₂) observed in preterm infants at saturation levels targeted in current trials.

Methods: In a cohort of 98 consecutive infants born at <29 weeks’ gestation, the Pao₂ from each arterial blood gas result during the first week of life (n = 2076) was matched to the Spo₂ at time of sampling. The mean (95% CI) Pao₂ was calculated for each saturation.

Results: The 95% CI of Pao₂ for the Spo₂ range 85–95% was 3.8 to 8.9 kPa. The mean (95% CI) Pao₂ at a saturation of 85% was 5.3 (3.8 to 6.8) kPa and at a saturation of 95% it was 7.2 (5.5 to 8.9) kPa.

Conclusion: Saturations within the range 85–95% largely exclude hyperoxia in preterm infants <29 weeks’ gestation but permit Pao₂ values far lower than those recommended in traditional guidelines.