Overview

Pulse oximeters are widely used in hospitals to estimate blood oxygen levels using a sensor placed on the skin. Recent studies suggest that pulse oximeter readings may be less accurate in individuals with darker skin tones, which could delay recognition of low oxygen levels.

The purpose of this study is to evaluate the accuracy of pulse oximeters across a range of skin tones and to identify factors associated with differences between pulse oximeter readings and oxygen levels measured directly from blood.

This is an observational cohort study involving adult patients who are already undergoing an arterial blood gas (ABG) test as part of routine clinical care. The ABG test is not performed for research purposes and is not altered by participation in the study.

At the time the ABG sample is obtained, two commercially available pulse oximeters will be temporarily placed on the participant's finger to record oxygen saturation values. These readings will be compared with the oxygen saturation measured from the arterial blood sample. Pulse oximeter measurements collected for the study will not be used for clinical decision-making.

Skin tone will be assessed using both self-reported race/ethnicity and an objective, noninvasive skin pigmentation measurement device. This approach allows evaluation of the relationship between skin pigmentation and pulse oximeter accuracy.

Participation in the study involves minimal risk. No additional blood samples, medications, or treatments are required. The study does not alter standard medical care.

The findings from this study may improve understanding of pulse oximeter performance and help inform future efforts to reduce measurement bias and improve patient safety.

Eligibility

Inclusion Criteria:

• Patients admitted to an intensive care unit, general medicine/surgery wards, or visiting the pulmonary function labs and/or outpatient pulmonary services clinics at Rush University Medical Center
• Patient has an existing order for an arterial blood gas analysis \[arterial line or puncture\]

Exclusion Criteria:

• Patients with heavy scar tissue on the sensor site
• Patients with hand tremors
• Opaque nail polish that cannot be removed