Abstract

Oxygen saturation (SpO₂) signal dropout leaves caregivers without a reliable measure to guide oxygen therapy. We studied SpO₂ dropout in preterm infants on continuous positive airway pressure, noting the SpO₂ values at signal loss and recovery and thus the resultant change in SpO₂, and the factors influencing this parameter. In 32 infants of median gestation 26 weeks, a total of 3932 SpO₂ dropout episodes were identified (1.1 episodes/h). In the episodes overall, SpO₂ decreased by 1.1%, with the SpO₂ change influenced by starting SpO₂ (negative correlation), but not dropout duration. For episodes starting in hypoxia (SpO₂ <85%), SpO₂ recovered at a median of 3.2% higher than at SpO₂ dropout, with a downward trajectory in a quarter of cases. We conclude that after signal dropout SpO₂ generally recovers in a relative normoxic range. Blind FiO₂ adjustments are thus unlikely to be of benefit during most SpO₂ dropout episodes.