New guidelines to force device manufacturers to make pulse oximeters more equitable for patients with darker skin have not been released by the Food and Drug Administration, despite agency officials saying for months new rules would be issued by Sept. 30.
It has been nearly four years since a group of physicians published clear evidence that pulse oximeters, the widely used fingertip devices that measure blood oxygen levels and are crucial in emergency and critical care, often missed low oxygen levels in patients with darker skin. Since then, studies have found these inaccuracies led to patients with darker skin being less likely to receive life-saving treatment during the Covid-19 pandemic and being less likely to receive supplemental oxygen they need — which can lead to death and organ failure.
The delay is frustrating many physicians who rely on the devices to gauge oxygen levels in extremely sick patients and know they are not working as well on their Black and Hispanic patients. “I should have had a better device by now,” said Theodore J. Iwashyna, a pulmonary and critical care physician and professor of medicine and public health at Johns Hopkins, who co-authored the December 2020 New England Journal of Medicine article that brought widespread attention to the issue. “How many more of my patients need to die before we fix this?”
FDA spokesperson Carly Kempler said the agency is working to get the guidance out as “expeditiously” as possible. Though the FDA had said it intended to release the revised pulse oximeter guidance during the fiscal year that ended Sept. 30, Kempler noted this is not a requirement. She did not say when the agency will release the guidance.
“Updating this guidance is a priority for the FDA’s Center for Devices and Radiological Health,” she said.
Guidances can often get caught up in the bureaucracy of government, subject to extra reviews and rounds of questions before being sent to the White House for final approval. Still, health equity advocates are questioning why it has taken the agency so long to address a clear issue impacting the safety of patients with darker skin.
“The FDA has a strong record of responding to safety signals,” said Iwashyna. “I don’t know why a strong safety signal that mostly affects Black patients has not gotten the same quick response.”
In people with darker skin, the pigment melanin can interfere with light absorption, making pulse oximeter readings less accurate. This fact had been noticed for decades among those developing new ways to measure blood oxygen, but was not well known among clinicians despite the devices being so ubiquitous. Even among those aware of the issue, it was rarely considered an urgent problem, something that many health equity advocates see as an example of the historical neglect of patients with black and brown skin. The FDA’s slow response, they say, follows a similar pattern.
Thomas Valley, a critical care physician at the University of Michigan and another co-author of the 2020 article, said he’d like to see more progress toward the development of better devices and also more specific guidance from the FDA for physicians in critical care, who remain confused about how to interpret pulse oximeter readings on patients with darker skin. “I would argue I’m one of the people who should know this issue the best and I still struggle with this,” he said.
The FDA’s slow response was called out by a group of 25 attorneys general in a letter last November that urged the agency to “act with urgency” to improve devices to reduce racial disparities in health care. “Not only is bias found in humans, but it is also ingrained in the devices and tools patients rely on,” California Attorney General Rob Bonta said when he sent the letter.
The FDA issued a safety communication about the devices in 2021, saying they “have limitations and a risk of inaccuracy” for a variety of reasons including skin tone. An FDA advisory committee held a meeting to discuss the devices’ flaws in November of 2022, published a discussion paper on the issue in November 2023, and held a second meeting in February of this year. The FDA has also funded work on studying the devices at a specialized lab at the University of California, San Francisco.
At the 2022 session, the advisory panel suggested the agency improve regulation of the devices, calling for clearer labeling and more rigorous testing. It specifically said that devices should be tested on more patients and on people with a fuller range of darker skin tones.
Current guidelines call for the devices to be tested on 10 patients, including two with “darkly pigmented” skin. One advisory panel member called the subject sizes “concerningly small for devices that affect the health of millions of patients.” Others have criticized the way device manufacturers have gauged skin tone, saying such measurements were not standardized and often subjective.
Iwashyna said he wanted to see the FDA act more quickly and do far more, including issue a “black box warning” so physicians know current devices are not as accurate on all patients, and enact stricter rules on testing to ensure all FDA approved devices are equitable. Device manufacturers have stated that they test their devices on diverse populations and have disagreed with studies showing the current devices cause clinical harm — a stance that Iwashyna said is standing in the way of progress. “I don’t know how you do better if you won’t admit you have a problem,” he said.
This is part of a series of articles exploring racism in health and medicine that is funded by a grant from the Commonwealth Fund.