Racial Disparity in Oxygen Saturation Measurements by Pulse Oximetry: Evidence and Implications

Jamali, Haya; Castillo, Lauren T; Morgan, Chelsea Cosby; Coult, Jason; Muhammad, Janice L; Osobamiro, Oyinkansola O; Parsons, Elizabeth C.; Adamson, Rosemary

doi:10.1513/annalsats.202203-270cme

Cited by 49 publications

(24 citation statements)

References 41 publications

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“…However, similar to a previous study [12], this delay was reduced to only a few minutes with no position change to avoid postural gas exchange modifications [32]. Otherwise, we did not exactly assess the skin pigmentation of the participants; that may be an inaccuracy factor in SpO 2 measurement (and so in PaO 2 computation by the AGM100) for the darkest skin tones [33]. However, patients included in the present study, all natives from Kyrgyzstan in Central Asia, had skin tones mostly ranging from fair to moderate-brown skin (type II to IV on the Fitzpatrick scale) that probably did not induce significant SpO 2 misestimations.…”

Section: Discussionmentioning

confidence: 97%

Validation of Noninvasive Assessment of Pulmonary Gas Exchange in Patients with Chronic Obstructive Pulmonary Disease during Initial Exposure to High Altitude

Champigneulle

Reinhard²,

Mademilov

et al. 2023

JCM

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Investigation of pulmonary gas exchange efficacy usually requires arterial blood gas analysis (aBGA) to determine arterial partial pressure of oxygen (mPaO2) and compute the Riley alveolar-to-arterial oxygen difference (A-aDO2); that is a demanding and invasive procedure. A noninvasive approach (AGM100), allowing the calculation of PaO2 (cPaO2) derived from pulse oximetry (SpO2), has been developed, but this has not been validated in a large cohort of chronic obstructive pulmonary disease (COPD) patients. Our aim was to conduct a validation study of the AG100 in hypoxemic moderate-to-severe COPD. Concurrent measurements of cPaO2 (AGM100) and mPaO2 (EPOC, portable aBGA device) were performed in 131 moderate-to-severe COPD patients (mean ±SD FEV1: 60 ± 10% of predicted value) and low-altitude residents, becoming hypoxemic (i.e., SpO2 < 94%) during a short stay at 3100 m (Too-Ashu, Kyrgyzstan). Agreements between cPaO2 (AGM100) and mPaO2 (EPOC) and between the O2-deficit (calculated as the difference between end-tidal pressure of O2 and cPaO2 by the AGM100) and Riley A-aDO2 were assessed. Mean bias (±SD) between cPaO2 and mPaO2 was 2.0 ± 4.6 mmHg (95% Confidence Interval (CI): 1.2 to 2.8 mmHg) with 95% limits of agreement (LoA): −7.1 to 11.1 mmHg. In multivariable analysis, larger body mass index (p = 0.046), an increase in SpO2 (p < 0.001), and an increase in PaCO2-PETCO2 difference (p < 0.001) were associated with imprecision (i.e., the discrepancy between cPaO2 and mPaO2). The positive predictive value of cPaO2 to detect severe hypoxemia (i.e., PaO2 ≤ 55 mmHg) was 0.94 (95% CI: 0.87 to 0.98) with a positive likelihood ratio of 3.77 (95% CI: 1.71 to 8.33). The mean bias between O2-deficit and A-aDO2 was 6.2 ± 5.5 mmHg (95% CI: 5.3 to 7.2 mmHg; 95%LoA: −4.5 to 17.0 mmHg). AGM100 provided an accurate estimate of PaO2 in hypoxemic patients with COPD, but the precision for individual values was modest. This device is promising for noninvasive assessment of pulmonary gas exchange efficacy in COPD patients.

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Section: Discussionmentioning

confidence: 97%

Validation of Noninvasive Assessment of Pulmonary Gas Exchange in Patients with Chronic Obstructive Pulmonary Disease during Initial Exposure to High Altitude

Champigneulle

Reinhard²,

Mademilov

et al. 2023

JCM

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“…While establishing different Sp o 2 thresholds according to skin pigmentation could lead to oversimplification, acknowledging limitations of Sp o 2 in clinical pathways may be a step in the right direction. At minimum, these data suggests that bedside providers and trainees should understand margins of error and carry an elevated index of suspicion of hypoxemia in darker skinned individuals when making decisions around respiratory support and care escalation (4, 43).…”

Section: Future Directionsmentioning

confidence: 99%

“…The pulse oximeter has revolutionized clinical care enabling inexpensive, continuous, noninvasive oxygenation measurements, facilitating prompt detection of desaturation before visible cyanosis, while avoiding frequent phlebotomy (1)(2)(3)(4). These devices have become standard care, ubiquitous in clinical arenas caring for critically ill children.…”

Section: Pulse Oximetry; a Primer On Limitationsmentioning

confidence: 99%

Discrimination by Design: Is It Time to Recalibrate Interpretation of Pulse Oximetry?*

Barreto

Moynihan²

2023

Pediatric Critical Care Medicine

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balanced representation of populations, and the role of disaggregation for calibration needs to be thoughtfully considered (44). Finally, race categories are inappropriate when what we are measuring is a color-tone scale rather than a social construct. In this research, investigators should endeavor to use objective measures of skin pigmentation over subjective definitions of race and ethnicity (45). CONCLUSIONSDespite being considered an objective measure, robust to implicit biases, pulse oximeters add to a mounting list of chronic racial biases in medicine that may inadvertently promote inequitable outcomes. As structural racism is pervasive, we must seek to critically evaluate all factors that potentially contribute to healthcare disparities. The simple pulse oximeter has numerous limitations. A multitiered approach to improving device accuracy is crucial to advancing healthcare for all but is especially important in improving care of patients who already experience significant health disparities due to their race and/or ethnicity.

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“…Observational data and laboratory studies suggest that pulse oximeters systematically overestimate arterial oxygen saturation among patients from minority racial and ethnic groups, leading to a greater risk of occult hypoxemia, generally defined as a true arterial oxygen saturation (SaO 2 ) below 88% with an oxygen saturation by pulse oximetry (SpO 2 ) in a normal range above 92% . The presence of occult hypoxemia has been associated with lower rates of supplemental oxygen among critically ill patients .…”

Section: Introductionmentioning

confidence: 99%

Clinical Outcomes Associated With Overestimation of Oxygen Saturation by Pulse Oximetry in Patients Hospitalized With COVID-19

Fawzy,

Wu,

Wang

et al. 2023

JAMA Netw Open

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ImportanceMany pulse oximeters have been shown to overestimate oxygen saturation in persons of color, and this phenomenon has potential clinical implications. The relationship between overestimation of oxygen saturation with timing of COVID-19 medication delivery and clinical outcomes remains unknown.ObjectiveTo investigate the association between overestimation of oxygen saturation by pulse oximetry and delay in administration of COVID-19 therapy, hospital length of stay, risk of hospital readmission, and in-hospital mortality.Design, Setting, and ParticipantsThis cohort study included patients hospitalized for COVID-19 at 186 acute care facilities in the US with at least 1 functional arterial oxygen saturation (SaO2) measurement between March 2020 and October 2021. A subset of patients were admitted after July 1, 2020, without immediate need for COVID-19 therapy based on pulse oximeter saturation (SpO2 levels of 94% or higher without supplemental oxygen).ExposuresSelf-reported race and ethnicity, difference between concurrent SaO2 and pulse oximeter saturation (SpO2) within 10 minutes, and initially unrecognized need for COVID-19 therapy (first SaO2 reading below 94% despite SpO2 levels of 94% or above).Main Outcome and MeasuresThe association of race and ethnicity with degree of pulse oximeter measurement error (SpO2 − SaO2) and odds of unrecognized need for COVID-19 therapy were determined using linear mixed-effects models. Associations of initially unrecognized need for treatment with time to receipt of therapy (remdesivir or dexamethasone), in-hospital mortality, 30-day hospital readmission, and length of stay were evaluated using mixed-effects models. All models accounted for demographics, clinical characteristics, and hospital site. Effect modification by race and ethnicity was evaluated using interaction terms.ResultsAmong 24 504 patients with concurrent SpO2 and SaO2 measurements (mean [SD] age, 63.9 [15.8] years; 10 263 female [41.9%]; 3922 Black [16.0%], 7895 Hispanic [32.2%], 2554 Asian, Native American or Alaskan Native, Hawaiian or Pacific Islander, or another race or ethnicity [10.4%], and 10 133 White [41.4%]), pulse oximetry overestimated SaO2 for Black (adjusted mean difference, 0.93 [95% CI, 0.74-1.12] percentage points), Hispanic (0.49 [95% CI, 0.34-0.63] percentage points), and other (0.53 [95% CI, 0.35-0.72] percentage points) patients compared with White patients. In a subset of 8635 patients with a concurrent SpO2 − SaO2 pair without immediate need for COVID-19 therapy, Black patients were significantly more likely to have pulse oximetry values that masked an indication for COVID-19 therapy compared with White patients (adjusted odds ratio [aOR], 1.65; 95% CI, 1.33-2.03). Patients with an unrecognized need for COVID-19 therapy were 10% less likely to receive COVID-19 therapy (adjusted hazard ratio, 0.90; 95% CI, 0.83-0.97) and higher odds of readmission (aOR, 2.41; 95% CI, 1.39-4.18) regardless of race (P for interaction = .45 and P = .14, respectively). There was no association of unrecognized need for COVID-19 therapy with in-hospital mortality (aOR, 0.84; 95% CI, 0.71-1.01) or length of stay (mean difference, −1.4 days; 95% CI, −3.1 to 0.2 days).Conclusions and RelevanceIn this cohort study, overestimation of oxygen saturation by pulse oximetry led to delayed delivery of COVID-19 therapy and higher probability of readmission regardless of race. Black patients were more likely to have unrecognized need for therapy with potential implications for population-level health disparities.

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Racial Disparity in Oxygen Saturation Measurements by Pulse Oximetry: Evidence and Implications

Cited by 49 publications

References 41 publications

Validation of Noninvasive Assessment of Pulmonary Gas Exchange in Patients with Chronic Obstructive Pulmonary Disease during Initial Exposure to High Altitude

Validation of Noninvasive Assessment of Pulmonary Gas Exchange in Patients with Chronic Obstructive Pulmonary Disease during Initial Exposure to High Altitude

Discrimination by Design: Is It Time to Recalibrate Interpretation of Pulse Oximetry?*

Clinical Outcomes Associated With Overestimation of Oxygen Saturation by Pulse Oximetry in Patients Hospitalized With COVID-19

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