Characterization of the bias between oxygen saturation measured by pulse oximetry and calculated by an arterial blood gas analyzer in critically ill neonates

Thomas Edward Bachman, Christopher J. L. Newth, Patrick A. Ross, Narayan P. Iyer, Robinder G. Khemani


Continuous monitoring of oxygenation with pulse oximetry is the standard of care for critically ill neonates. A better understanding of its measurement bias compared to arterial oxygen saturation could be helpful both for the clinician and researcher. Towards that end, we examined the electronic database from a large neonatal ICU. From a 24-month period we identified 23,032 paired SpO2-SaO2 measurements from 1,007 infants who were receiving supplemental oxygen during mechanical ventilation. We found that SpO2 was consistently higher than SaO2. The size of the bias was fairly constant when SpO2 was between 75-93%, above which it dropped steadily. The median size of this bias was 1% SpO2 during hyperoxemia (SpO2 97-100%) with a median variation of 1.3% above and below. During periods of hypoxemia (SpO2 75-85%) and normoxemia (SpO2 89-93%) the bias was approximately 5% SpO2, with a median variation of 5% above and below.


Pulse oximetry, neonatal oxygenation, oxygen saturation


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ISSN 0301-5491 (Print)
ISSN 2336-5552 (Online)
Published by the Czech Society for Biomedical Engineering and Medical Informatics and the Faculty of Biomedical Engineering, Czech Technical University in Prague.