PaO₂ values in infants <29 weeks of gestation at currently targeted saturations

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% C.I.) PaO₂ was calculated for each saturation.

Results: The 95% confidence intervals of PaO₂ for the SpO₂ range 85-95% were 3.8-8.9 kPa. The mean (95% C.I.) PaO₂ at a saturation of 85% was 5.3 (3.8-6.8) kPa and at a saturation of 95% was 7.2 (5.5-8.9) 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.