CHESTCHEST NewsInaccuracy of pulse oximeters based on skin pigmentation requires additional FDA regulation

Inaccuracy of pulse oximeters based on skin pigmentation requires additional FDA regulation

February 10, 2022

Through the Critical Care Societies Collaborative (CCSC), CHEST is urging the FDA to direct developers and manufacturers of FDA-regulated pulse oximeters to test all devices to ensure accurate and reliable readings for patients with diverse degrees of skin pigmentation. The technology underlying pulse oximetry has evolved since its inception, yet concerns have persisted for more than five decades about the potential inaccuracy of pulse oximetry in people with darker skin tones.

The first request to the FDA was made in March 2021 (read the March 2021 letter to the FDA). The FDA responded stating that they are “working with manufacturers and testing laboratories in additional post-market data analysis to better understand how different factors, including skin pigmentation, may affect pulse oximeter accuracy and assure that appropriate testing is performed…”

The FDA went on to say that they are looking at new findings from published research or post-market data analysis to determine if the pulse oximetry guidance document should be reassessed. Read the full response from the FDA.

In the time following this correspondence, a new peer-reviewed research article, “Analysis of Discrepancies Between Pulse Oximetry and Arterial Oxygen Saturation Measurements by Race and Ethnicity and Association With Organ Dysfunction and Mortality,” was published in JAMA. The data indicate that the inaccuracies of pulse oximeters place Black patients at higher risk of death.

The CCSC issued a new letter to the FDA drawing attention to the new information (Full letter below).

“In medical clinics and even the home environment, pulse oximeters can provide guidance as to when someone needs to seek more aggressive medical care. If these readings are inaccurate, there could be serious implications,” said CHEST President David Schulman, MD, FCCP. “The significant disparities in the accuracy of pulse oximetry across varied skin pigmentation is an urgent issue that warrants better regulation and more urgent attention from the FDA.”

This communication is the result of advocacy efforts driven by CHEST on behalf of patients with lung disease and the clinicians who treat them. Members interested in participating in committee activities should contact advocacy@chestnet.org.

February 7, 2022

Jeffrey Shuren, MD, JD,
CDRH Center Director
Via email: jeff.shuren@fda.hhs.gov

Dear Dr. Shuren:

This correspondence is in reply to your April 27, 2021 reply to our earlier communication from March 31, 2021 regarding the accuracy of FDA-regulated pulse oximetry across the spectrum of patient populations, particularly among those with darker skin color. We are writing to bring significant new information to your attention, which you indicated would be important for informing healthcare providers and the public.

As you know, pulse oximetry is one of the most common measures in healthcare, used either intermittently or continuously in millions of acutely and critically ill patients each year. Accurate measurement of arterial blood oxygen saturation via pulse oximetry is vital to the clinical management of patients. The universal application of these devices and the need for accuracy when caring for patients in intensive care make this issue both urgent and important for clinicians.

Since our earlier correspondence, additional peer-reviewed data have emerged that change the risk assessment and the utilization of pulse oximeters for patient monitoring. In addition to the earlier cited clinical data demonstrating that hospitalized Black patients had a higher rate of occult and clinically significant arterial hypoxemia compared to White patients (11.7%-17.0% vs. 3.6%-6.2%),¹ new data indicate that the inaccuracies of pulse oximeters place Black patients at higher risk of death. Specifically, in a clinical study of 141,600 hospital encounters in the United States, occult decrements in arterial oxygen saturation, or “hidden hypoxemia,” occurred more frequently in Black patients. These findings were strongly associated with critical organ dysfunction and a 41% increase in the risk of death (21.1% vs. 15.0%, P < 0.001).² Further, these results were validated and reproduced in a separate study of 128,285 paired SpO2-SaO2 measurements from 26,603 perioperative or critically ill adults from three independent health systems. In this replication study, occult hypoxemia was common and strongly associated with mortality in Blacks (odds ratio for death = 2.96 for surgical patients, 1.36 for ICU patients, both P < 0.01).³ Taken together, the preponderance of biomedical data now indicates that pulse oximeters are more likely to be inaccurate in patients with darker skin color and that such inaccuracies put patients with darker skin color at risk of occult hypoxemia leading to organ dysfunction and death.

We are aware of the unchanged FDA guidance on this subject issued February 19, 2021.⁴ With the emergence of these new data indicating a substantially increased risk of death associated with occult hypoxemia in patients with darker skin color, we urge the FDA to directly engage the developers and manufacturers of all pulse oximeters to rectify this urgent situation in a timely manner. It is vitally important that your agency direct pulse oximeter manufacturers to conduct the tests needed to ensure that the devices provide accurate and reliable readings for patients with diverse degrees of skin pigmentation. We appreciate your commitment to working with manufacturers and testing laboratories to understand how important factors, such as skin pigmentation, affect pulse oximeter accuracy, and we agree with your earlier assessment that providers and consumers must be made aware of the potential limitations of pulse oximetry.

Thank you for your consideration and your efforts to remove this barrier to high-quality equitable healthcare for all U.S. residents.

The Critical Care Societies Collaborative (CCSC) is a unique partnership comprising the four major professional and scientific societies whose members care for America’s critically ill and injured patients. The CCSC leverages its collective and multiprofessional expertise through communication, education, research, and advocacy efforts. The CCSC speaks with a unified voice, representing nearly 200,000 critical care professionals to bring important issues to the forefront of public policy and healthcare.

Sincerely,

Greg S. Martin, MD, MSc, FCCM
President
Society of Critical Care Medicine

Beth A. Wathen, MSN, RN, CCRN-K
President
American Association of Critical-Care Nurses

David A. Schulman, MD, MPH, FCCP
President
American College of Chest Physicians

Lynn M. Schnapp, MD, ATSF
President
American Thoracic Society

References:

1. Wong AKI, 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 Netw Open. 2021 Nov 1;4(11):e2131674.

2. Henry NR, Hanson AC, Schulte PJ, et al. Disparities in hypoxemia detection by pulse oximetry across self-identified racial groups and associations with clinical outcomes. Crit Care Med. 2022 Feb 1;50(2):204-211.

3. Sjoding MW, Dickson RP, Iwashyna TJ, Gay SE, Valley TS. Racial bias in pulse oximetry measurement. N Engl J Med. 2020 Dec 17;383(25):2477-2478.

4. U.S. Food and Drug Administration. Pulse oximeter accuracy and limitations: FDA Safety Communication. Issued February 19, 2021. Accessed January 18, 2022. https://www.fda.gov/medical-devices/safety-communications/pulse-oximeter-accuracy-and-limitations-fda-safety-communication