There is high variability in arterial oxygen saturation (SaO2) for fixed pulse oximetry (SpO2) readings, with the largest discrepancy observed in patients who reported themselves to be Black, Asian, and Hispanic compared to those who reported themselves to be Black, Asian, and Hispanic who have favourited self-disclosure as white. A multicenter, retrospective cross-sectional study was carried out, which included 5 databases. The results of the analysis were published in the JAMA Network Open.
Researchers attempted to examine ethnic and racial differences between SaO2 and SpO2 measurements and their relationship to clinical outcomes. They used 3 publicly available electronic databases of the US health record (ie the electronic database for clinical research in the intensive care unit [eICU-CRD], the medical information market for intensive care medicine III [MMIC-III], and the Medical Information Mart for Critical Care IV [MMIC-IV]), together with the databases of 2 health organizations in the Atlanta, GA area: Emory Healthcare (from 2014 to 2021; 277 units, including 26 intensive care units) [ICUs] in 4 hospitals) and Grady Memorial (from 2014 to 2020; 73 units, including 9 intensive care units, in 1 hospital).
The main outcome measures of the study included SaO2 for each SpO2; Prevalence of hidden hypoxemia; initial demographics (ie age, gender); clinical outcomes (ie length of hospital stay, hospital mortality); Laboratory values (ie lactate and creatinine levels); and organ dysfunction by scores (ie, sequential organ failure assessment [SOFA]) before and 24 hours after arterial blood gas [ABG] Measurement).
From a total of 141,600 hospital visits with recorded arterial ABG measurements, a total of 87,971 participants with an initial ABG measurement and an SpO2 of at least 88% within 5 minutes before the ABG test were included in the analysis. A total of 37,713 of these participants were women; the mean patient age was 62.2 ± 17.0 years; 1919 patients were Asians, 26,032 blacks, 2,397 Hispanics, and 57,632 white. Hidden hypoxemia was reported with varying incidences in a total of 4859 participants – black patients: n = 1785; Hispanic patients: n = 160; Asian patients: n = 92; and white patients: n = 2822 (P <0.001).
These rates of hidden hypoxemia were associated with greater organ dysfunction 24 hours after receiving the ABG measurement, as seen with higher mean SOFA scores and significantly higher hospital mortality in black patients compared to white patients (P <0.001). In addition, prior to ABG measurement, patients with hidden hypoxemia had significantly higher mean serum creatinine levels and serum lactate levels (p <0.001 for both) than patients without hypoxemia.
Researchers concluded that, “In this study, discrepancies in pulse oximetry accuracy between ethnic and ethnic subgroups were associated with higher rates of hidden hypoxemia, mortality, and organ dysfunction,” with results showing “greater variability in oxygen saturation at a given SpO2 Value ”among those who identified themselves as Black, followed by those who identified as Hispanic, Asians and Whites.” In light of these results, they added, “The validation of all health technologies, including pulse oximetry, needs to be broader Spectrum of patient populations to prevent damage caused by incorrect calibration from persisting. “
Disclosure: Some of the study authors have stated that they belong to biotech, pharmaceutical and / or device companies. For a full list of specifications, see the original reference.
Wong AI, Charpignon M, Kim H et al. Analysis of discrepancies between pulse oximetry and arterial oxygen saturation measurements by race and ethnicity and association with organ dysfunction and mortality. JAMA network open. 2021; 4 (11): e2131674. doi: 10.1001 / jamanetworkopen.2021.31674
This article originally appeared on Pulmonology Advisor