Pulse oximeter devices often miss low oxygen levels in Black patients. What a Wisconsin official wants done about it
Attorneys general in Wisconsin and other states are urging the federal Food and Drug Administration to address a flaw in devices used to measure a person's blood oxygen level that tend to give faulty readings for people of color.
The devices, called pulse oximeters, were critical in making care decisions for COVID-19 patients at the height of the pandemic, when a low blood oxygen level might mean a patient needed supplemental oxygen, antivirals or other treatments.
Studies have found that pulse oximeters often register higher, or healthier, oxygen level readings in people with darker skin tones, leading many experts to believe their unreliability contributed to the pandemic's disproportionate toll, including higher mortalitiy rates, in communities of color.
Wisconsin Attorney General Josh Kaul and two dozen other attorneys general signed a letter Wednesday to the FDA calling for clear warning labels on pulse oximeters to warn medical providers and patients that the devices can be less accurate on Black and brown patients. They also called for stronger regulations around the testing of pulse oximeters, urging the FDA to adopt requirements for racially diverse representation in clinical trials.
"This issue highlights the importance of identifying disparities in the health care system and acting promptly to eliminate those disparities," Kaul said in a statement.
The devices' inaccuracies, the letter said, can lead to delays in diagnosis, hospital admission and treatment that could further harm the patient.
Pulse oximeters clasp around a fingertip and use light to estimate oxygen in the blood, according to the FDA. The general hypothesis is that darker skin pigmentation interferes with the passage of light, rendering inaccurate results, Amal Jubran, a pulmonologist at Loyola University Medical Center in Illinois, told USA Today. That’s why the FDA, for example, recommends removing nail polish before using an oximeter.
A study published in the New England Journal of Medicine in December 2020 compared patients' pulse oximeter readings with measurements taken by arterial blood gas tests.
The analysis of University of Michigan Hospital patients found that 11.7% of Black patients registered higher than accurate blood oxygen levels on pulse oximeters compared to 3.6% of white patients. That means low blood oxygen levels went undetected about three times more often among Black patients than among white patients.
The study prompted the FDA to issue a February 2021 advisory warning patients and providers to consider the limitations and “risks of inaccuracy” in pulse oximeters.
Patients in the University of Michigan study who received inaccurate oximeter readings posted oxygen saturation levels of 92% to 96%, when their levels were actually less than 88%.
The Centers for Disease Control and Prevention recommends starting starting oxygen therapy for COVID-19 patients with saturation levels of 90% or less.
Last November, the FDA convened an panel of the Medical Devices Advisory Committee to discuss ongoing concerns about pulse oximeters and said it would consider the committee's recommendations.
In their letter, the attorneys general asked the FDA to take additional steps, including:
Requiring manufacturers and vendors of pulse oximeters to include warning labels to all users about the device’s effectiveness based on skin tones.
Calling for inclusion of similar warnings in other medical devices that incorporate pulse oximeter readings, such as medical device software used for diagnosis or treatment of medical conditions.
Issuing guidance to healthcare providers about the risks and reduced efficacy of pulse oximeters for patients of color.
Implementing an expedited timeline for FDA to quickly review the Medical Devices Advisory Committee’s recommendations
USA Today reporter Orlando Mayorquin contributed to this story.
This article originally appeared on Milwaukee Journal Sentinel: Kaul presses FDA to address racial bias in pulse oximeter devices
