Objectives Reference ranges for pulse oximetry (PO) measurements of oxygen saturation (SpO2) and heart rate (HR) in infants at birth were generated excluding measurements with system messages (SyM), such as ‘Low Signal Quality’ or ‘Low perfusion’. However, in clinical practice SyM often occur and may not be noticed. To assess the usability of measurements obtained with SyM, we investigated the differences of SpO2 and HR between measurements with and without SyM and if reference ranges would change when including data with SyM.
Methods HR and SpO2 of uncompromised term infants were recorded using Masimo PO. Differences in mean and standard deviation (SD) between measurements with and without SyM were calculated and compared with permutation tests. Centile charts were computed with and without SyM.
Results PO values of 138 neonates were obtained, resulting in 28,477 data points. SyM occurred in 46% of measurements. Most SyM occurred in the 3rd and 4th minute after birth. Mean SpO2 with SyM was lower (p < 0.001), SD was similar to data without SyM. SyM included, centile charts of SpO2 are approximately 3% lower, but not more dispersed. Mean HR was lower (p < 0.001) and more dispersed (p < 0.001) when SyM occurred. SyM included centile charts of HR have increased variability and are lower.
Conclusion In term infants at birth SyM on PO occurred frequently. SpO2 measurements with SyM are reliable for monitoring an infant’s clinical condition. However, HR measurements with SyM should be used with caution as they may underestimate an infant’s HR.