Circadian Variability of Pulse Oximetry in Healthy Children Under the Age of 7

Abstract

BackgroundPeripheral oxygen saturation (SpO2) measured by pulse oximetry is widely used in clinical practice, but its fluctuations over the course of the 24h of a day have not been explored at length. Recently, we reported that children hospitalized due to non-cardiopulmonary causes had a circadian variation in SpO2. This finding needed to be corroborated in healthy children, which is the objective of the present study. Patients and methodsHealthy children residing in a state foster home were studied with pulse oximetry every 2h for 24h. ResultsEighty-two children were included in the study, ranging in age from 1 month to 6.5 years (average±standard error of 3.06±0.16 years), with a weight-for-length/height percentile of 65.5±2.9. In 65 (79.3%) children, the SpO2 levels followed a sinusoidal curve suggesting circadian rhythm. The total group of sinusoidal curves in this population had a mesor of 95.10±0.08%SpO2, period of 21.05±0.54h (in 53.8% of these children, the period was between 20 and 28h). The maximum SpO2 was reached at 3:14pm±16min, and the minimum at 5:16am±48min. When the 24h were divided into four periods, it was demonstrated that the highest SpO2 levels were reached between 2pm and 8pm. ConclusionsIn this population of clinically healthy children, there was a circadian variation in pulse oximetry, with maximum values in the late afternoon and minimal values in the early morning.