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Comparative Study
. 2021 Nov 1;4(11):e2131674.
doi: 10.1001/jamanetworkopen.2021.31674.

Analysis of Discrepancies Between Pulse Oximetry and Arterial Oxygen Saturation Measurements by Race and Ethnicity and Association With Organ Dysfunction and Mortality

An-Kwok Ian Wong  1   2 , Marie Charpignon  3 , Han Kim  4 , Christopher Josef  5 , Anne A H de Hond  6   7 , Jhalique Jane Fojas  8 , Azade Tabaie  9 , Xiaoli Liu  10 , Eduardo Mireles-Cabodevila  10 , Leandro Carvalho  11   12 , Rishikesan Kamaleswaran  9 , R W M A Madushani  13 , Lasith Adhikari  14 , Andre L Holder  1 , Ewout W Steyerberg  6 , Timothy G Buchman  5 , Mary E Lough  15   16 , Leo Anthony Celi  17   18   19
Affiliations
Comparative Study

Analysis of Discrepancies Between Pulse Oximetry and Arterial Oxygen Saturation Measurements by Race and Ethnicity and Association With Organ Dysfunction and Mortality

An-Kwok Ian Wong et al. JAMA Netw Open. .

Erratum in

  • Incorrect Numbers in eTable and Text.
    [No authors listed] [No authors listed] JAMA Netw Open. 2022 Feb 1;5(2):e221210. doi: 10.1001/jamanetworkopen.2022.1210. JAMA Netw Open. 2022. PMID: 35138406 Free PMC article. No abstract available.

Abstract

Importance: Discrepancies in oxygen saturation measured by pulse oximetry (Spo2), when compared with arterial oxygen saturation (Sao2) measured by arterial blood gas (ABG), may differentially affect patients according to race and ethnicity. However, the association of these disparities with health outcomes is unknown.

Objective: To examine racial and ethnic discrepancies between Sao2 and Spo2 measures and their associations with clinical outcomes.

Design, setting, and participants: This multicenter, retrospective, cross-sectional study included 3 publicly available electronic health record (EHR) databases (ie, the Electronic Intensive Care Unit-Clinical Research Database and Medical Information Mart for Intensive Care III and IV) as well as Emory Healthcare (2014-2021) and Grady Memorial (2014-2020) databases, spanning 215 hospitals and 382 ICUs. From 141 600 hospital encounters with recorded ABG measurements, 87 971 participants with first ABG measurements and an Spo2 of at least 88% within 5 minutes before the ABG test were included.

Exposures: Patients with hidden hypoxemia (ie, Spo2 ≥88% but Sao2 <88%).

Main outcomes and measures: Outcomes, stratified by race and ethnicity, were Sao2 for each Spo2, hidden hypoxemia prevalence, initial demographic characteristics (age, sex), clinical outcomes (in-hospital mortality, length of stay), organ dysfunction by scores (Sequential Organ Failure Assessment [SOFA]), and laboratory values (lactate and creatinine levels) before and 24 hours after the ABG measurement.

Results: The first Spo2-Sao2 pairs from 87 971 patient encounters (27 713 [42.9%] women; mean [SE] age, 62.2 [17.0] years; 1919 [2.3%] Asian patients; 26 032 [29.6%] Black patients; 2397 [2.7%] Hispanic patients, and 57 632 [65.5%] White patients) were analyzed, with 4859 (5.5%) having hidden hypoxemia. Hidden hypoxemia was observed in all subgroups with varying incidence (Black: 1785 [6.8%]; Hispanic: 160 [6.0%]; Asian: 92 [4.8%]; White: 2822 [4.9%]) and was associated with greater organ dysfunction 24 hours after the ABG measurement, as evidenced by higher mean (SE) SOFA scores (7.2 [0.1] vs 6.29 [0.02]) and higher in-hospital mortality (eg, among Black patients: 369 [21.1%] vs 3557 [15.0%]; P < .001). Furthermore, patients with hidden hypoxemia had higher mean (SE) lactate levels before (3.15 [0.09] mg/dL vs 2.66 [0.02] mg/dL) and 24 hours after (2.83 [0.14] mg/dL vs 2.27 [0.02] mg/dL) the ABG test, with less lactate clearance (-0.54 [0.12] mg/dL vs -0.79 [0.03] mg/dL).

Conclusions and relevance: In this study, there was greater variability in oxygen saturation levels for a given Spo2 level in patients who self-identified as Black, followed by Hispanic, Asian, and White. Patients with and without hidden hypoxemia were demographically and clinically similar at baseline ABG measurement by SOFA scores, but those with hidden hypoxemia subsequently experienced higher organ dysfunction scores and higher in-hospital mortality.

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Conflict of interest statement

Conflict of Interest Disclosures: Dr Wong reported holding equity and management roles in Ataia Medical outside the submitted work. Dr Josef reported receiving grants from the National Institutes of Health during the conduct of the study. Dr Madushani reported receiving grants from the National Institute on Drug Abuse outside the submitted work. Dr Holder reported receiving grants from the National Institutes of Health during the conduct of the study and receiving speakers’ fees from Baxter international outside the submitted work. Dr Buchman reported that Emory University received funding from the US government for Dr Buchman’s role as senior advisor and IPA to the Division of Research, Innovation, and Ventures within BARDA; furthermore, he reported serving as editor in chief of Critical Care Medicine and receiving grants from Henry M. Jackson Foundation. No other disclosures were reported.

Figures

Figure 1.
Figure 1.. Flow Diagram
Aggregate flow diagram for all data sets. ABG indicates arterial blood gas; Sao2, arterial oxygen saturation; Spo2, oxygen saturation by pulse oximetry.
Figure 2.
Figure 2.. Modified Bland-Altman Plots by Race and Ethnicity
On each plot, the bold horizontal lines represent the mean bias (defined as the difference between the oxygen saturation measured by pulse oximetry [Spo2] and arterial blood gas value [Sao2]) for each of the 2 Spo2 groups. The blue lines, with dashed blue lines indicating 95% CIs, are for the group with Spo2 of 88% to 92%, and the orange lines, with dashed orange lines indicating 95% CIs, for the group with Spo2 of 93% to 96%. The solid black line indicates the absence of bias (ie, Spo2 − Sao2 = 0). When the mean bias is above the black line, there is positive bias in the pulse oximetry measurement (ie, the observed Spo2 is greater than the true Sao2). In contrast, when the mean bias is below the black line, there is negative bias in the pulse oximetry measurement (ie, the observed Spo2 is below the true Sao2).
See this image and copyright information in PMC

References

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