Pulse Oximeters Overestimate Oxygen Saturation in people with Darker Skin Tone: Study

Pulse oximetry is commonly used to measures oxygen levels in the blood non-invasively. However, concerns have arisen regarding its reliability in individuals with darker skin tones. A recent review published in the British Journal of Anaesthesia explored the accuracy of pulse oximeters in estimating arterial oxygen saturation (SaO2) across different skin tones.

This comprehensive review encompassed a total of 44 studies and over 222,000 participants and found that pulse oximeters tended to overestimate SaO2 in individuals with darker skin tones. While the majority of studies reported this bias, a few indicated no significant inaccuracy related to skin tone.

Despite the extensive data sieved through, meta-analysis could not be conducted due to the considerable heterogeneity in study design and reporting metrics. Importantly, only a quarter of the studies measured skin tone directly, while the others relied on participant ethnicity, with approximately 31% of participants being of non-White ethnicity or having non-light skin tones. The review emphasized the importance of recognizing this bias in pulse oximetry that can overestimate true SaO2 in people with darker skin tones. 

This finding raises critical concerns in medical scenarios where accurate oxygen saturation readings are paramount for the management of the patients. While the exact impact of this bias on clinical outcomes requires further investigation, the awareness of its existence is crucial for healthcare providers.

The study illuminates the need for improved diversity and inclusion to address disparities in healthcare outcomes across different demographic groups. The outcomes prompt healthcare professionals to remain cautious and consider the potential inaccuracies when interpreting oxygen saturation readings, particularly in patients with darker skin tones.

Source:

Martin, D., Johns, C., Sorrell, L., Healy, E., Phull, M., Olusanya, S., Peters, M., & Fabes, J. (2024). Effect of skin tone on the accuracy of the estimation of arterial oxygen saturation by pulse oximetry: a systematic review. In British Journal of Anaesthesia. Elsevier BV. https://doi.org/10.1016/j.bja.2024.01.023