Related Experiment Video
Updated: May 20, 2025
Author Spotlight: Exploring Venous Waveforms for Non-Invasive Respiratory Monitoring in Pigs
Published on: March 8, 2024
Race and the Inaccuracy of Pulse Oximetry With Hypoxemia in a Pediatric Cardiac ICU
Matthew T Coghill1, Mark A Law1, Lece V Webb2
1Department of Pediatric Cardiology, Section of Cardiac Critical Care, University of Alabama at Birmingham, Birmingham, AL.
Insights
Pulse oximetry may overestimate oxygen saturation in Black patients compared to White patients, especially with hypoxemia. This race-related bias in pulse oximetry readings requires further investigation in clinical settings.
Area of Science:
- Cardiology
- Critical Care Medicine
- Biomedical Engineering
Background:
- Pulse oximetry is a vital sign for monitoring oxygen saturation.
- Hypoxemia is common in intensive care unit (ICU) patients, particularly those with congenital heart disease.
- Previous studies suggest potential racial disparities in pulse oximetry accuracy.
Purpose of the Study:
- To investigate the impact of hypoxemia and race on pulse oximetry readings.
- To evaluate pulse oximetry accuracy in pediatric cardiac ICU patients with intracardiac mixing.
Main Methods:
- Retrospective, observational cohort study of 841 pediatric patients undergoing bypass operations.
- Time-matched, high-fidelity comparison of pulse oximeter values with hemoximeter-measured arterial oxygen saturation (Sao2).
Main Results:
- A greater mean oximetric difference (pulse oximetry overestimation) was observed in Black patients compared to White patients (-3.18% vs. -2.19%).
- Oximetric difference increased with worsening hypoxemia and was more pronounced in Black patients at normal oxygen saturations (Sao2 > 94%).
- Race showed a statistically significant, albeit mild, effect on oximetric difference.
Conclusions:
- Increasing hypoxemia exacerbates the oximetric difference, indicating pulse oximetry overestimation.
- Race may independently influence pulse oximetry accuracy, potentially introducing race-related bias.
- Findings highlight the need to consider potential biases in pulse oximetry interpretation as a vital sign.
Objectives:
To ascertain the potential effects of hypoxemia and race on pulse oximetry in a population of patients, including those for whom hypoxemia is a normal state secondary to intracardiac mixing in an ICU setting.
Design:
Retrospective, observational, cohort study.
Setting:
A single center's pediatric cardiac ICU (CICU).
Patients:
Eight hundred forty-one patients undergoing bypass operations during a 52-month period (June 2019-October 2023). Predominantly, patients with congenital heart disease. The median age was 7.1 months with 58% younger than 1 year old and 88% younger than 10 years old.
Interventions:
Arterial blood saturations, as measured by a hemoximeter, were recorded for all patients after bypass operations. These were time-matched, with high-fidelity, to pulse oximeter values.
Measurements And Main Results:
The mean oximetric difference, or "pulse oximetry overestimation," was defined as arterial oxygen saturation minus that predicted by pulse oximetry, was greater for Black than for White patients (-3.18% vs. -2.19%, p = 0.006). Regression shows a significant effect of Sao2 on oximetric difference (p < 0.001) and mildly significant trend for the categorical race (p = 0.03) as well as their composite interaction term (p = 0.047). Oximetric difference was exaggerated with increasing hypoxemia. At normal oxygen saturations, the oximetric difference was greater for Black when compared with White patients (p = 0.002 for patients with Sao2 > 94%). This effect if race is not statistically significant at other Sao2 ranges that are clinically important in patients with intracardiac mixing.
Conclusions:
This study redemonstrates effect of increasing hypoxemia on oximetric difference. Race may have an independent effect on oximetric difference. This adds to the body of literature that has previously suggested that pulse oximetry, relied upon as a vital sign, may introduce explicit race-related bias into the bedside interpretation of a patient's clinical state.
Related Concept Videos
01:24Pulse Oximetry
Purpose
Average SpO2 values are greater than 95%. If the readings fall below 90%, it indicates that...
01:19Special considerations while measuring oxygen saturation
Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is...
01:19Guidelines For Measuring Vital Signs
Before taking a patient's vital signs, a nurse would consider and assess the patient's comfort level and ensure appropriate equipment is available.
01:21Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
01:13Special considerations while measuring pulse
01:19Respiratory Assessment: Purpose and Indications
Objectives and Importance:
The primary goal of respiratory assessment is to evaluate patients at early risk of clinical deterioration. Since respiratory distress often precedes other signs of declining health, breathing patterns and sounds become a...