Racial Bias in Pulse Oximetry Measurement Among Patients About to Undergo Extracorporeal Membrane Oxygenation in 2019-2020: A Retrospective Cohort Study

Abstract

Pulse oximeters may produce less accurate results in non-White patients. Do pulse oximeters detect arterial hypoxemia less effectively in Black, Hispanic, and/or Asian patients than in White patients in respiratory failure and about to undergo extracorporeal membrane oxygenation (ECMO)? Data on adult patients with respiratory failure readings 6h before ECMO were provided by the Extracorporeal Life Support Organization registry. Data was collected from 324 centers between January 2019 and July 2020. Our primary analysis was of rates of occult hypoxemia-low arterial oxygen saturation (Sao2≤ 88%) on arterial blood gas measurement despite a pulse oximetry reading in the range of 92%to 96%. The rate of pre-ECMO occult hypoxemia, that is, arterial oxygen saturation (Sao2)≤ 88%, was 10.2%(95%CI, 6.2%-15.3%) for 186 White patients with peripheral oxygen saturation (Spo2) of 92%to 96%; 21.5%(95%CI, 11.3%-35.3%) for 51 Black patients (P= .031 vsWhite); 8.6%(95%CI, 3.2%-17.7%) for 70 Hispanic patients (P= .693 vsWhite); and 9.2%(95%CI, 3.5%-19.0%) for 65 Asian patients (P= .820 vsWhite). Black patients with respiratory failure had a statistically significantly higher risk of occult hypoxemia with an OR of 2.57 (95%CI, 1.12-5.92) compared with White patients (P= .026). The risk of occult hypoxemia for Hispanic and Asian patients was equivalent to that of White patients. In a secondary analysis of patients with Sao2≤ 88%despite Spo2 > 96%, Black patients had more than three times the risk compared with White patients (OR, 3.52; 95%CI, 1.12-11.10; P= .032). Compared with White patients, the prevalence of occult hypoxemia was higher in Black patients than in White patients about to undergo ECMO for respiratory failure, but it was comparable in Hispanic and Asian patients compared with White patients.