The Food and Drug Administration (FDA) is considering changes to how it determines which pulse oximeters to approve for medical use. Its goal is to ensure accuracy in measuring blood oxygen saturation for people of all skin tones.
Those changes include increasing sample sizes and representation across skin pigmentation during device testing as well as more stringent accuracy measures.
“Disparate performance of pulse oximeters across people with different amounts of skin pigmentation, racial and ethnic groups is of great importance to the public health and the FDA,” Jeff Shuren, M.D., J.D., director of the FDA’s Center for Devices and Radiological Health, said at a meeting of the Anesthesiology and Respiratory Therapy Devices Panel of the Medical Devices Advisory Committee.
The group spent all day Friday discussing studies and input from patients, industry and medical associations, and providing the FDA with feedback on its proposed changes to premarket studies.
The AAP was among the groups providing expert input. Joseph L. Wright, M.D., M.P.H., FAAP, chief health equity officer and senior vice president, equity initiatives, spoke about AAP efforts to encourage development and testing of medical devices for children, understanding they have unique anatomy and physiology. He also emphasized the AAP’s commitment to health equity.
“The Academy encourages the FDA to fully support completion of studies that are currently underway to equitably address the unique needs of children of all (melanin levels) as innovative technologies and devices are developed that mitigate current inequities.”
Pulse oximeters are a noninvasive way to measure blood oxygen saturation using light beams. They are used in hospitals and doctor’s offices as well as in a patient’s home via a prescription or over-the-counter purchase. Dr. Shuren called them a “vital public health tool.”
The devices became ubiquitous during the COVID-19 pandemic. However, studies have found people with darker skin pigmentation can have varying measurements, which can impact treatment for serious health conditions.
In February 2021, the FDA issued a safety communication outlining factors that may affect the accuracy of readings, including skin pigmentation, poor circulation, skin thickness, skin temperature, tobacco use and fingernail polish. It encouraged people to pay attention to other symptoms like shortness of breath and bluish coloration of the face, lips or nails and to contact their health care provider if symptoms increased or worsened.
The FDA turned to its expert committee Friday to get input on updating its 2013 guidance to industry and staff on testing the devices for approval.
The FDA has proposed manufacturers test the devices on at least 24 participants, up from 10. In addition, it would like to use both an objective and subjective measurement of skin pigmentation in test subjects. The new subjective tool would be the Monk Skin Tone scale, which has a broader range of skin tones than other scales and was widely supported by the committee. It proposed using the individual typology angle (ITA) as an objective measure of skin pigmentation, which sparked mixed reactions.
“It seems like the committee likes the subjective and objective approach to these premarket studies,” said Chairman Hugh A. Cassiere, M.D., FCCP, FACP, director of critical care for South Shore University Hospital in Bay Shore, New York. “The Monk scale seems to be on point, which is good for a subjective approach. It seems we have some buy-in for ITA even though it may not be extensively studied and there may be some variability. … You’ve got to be pragmatic.”
Some committee members questioned whether 24 healthy patients would be enough, and some were concerned about laboratory testing translating to sick patients in clinical settings.
“Sure we can increase the numbers to 48, to 100, whatever the magic number is and we will increase the precision of pulse oximetry performance in that population of healthy adult volunteers that can be desaturated in the laboratory. But the question really still remains what the heck is going on in these clinical environments that are causing the numbers that are raising such concern,” said Julian M. Goldman, M.D., FASA, an anesthesiologist at Massachusetts General Hospital.
The group also had extensive discussions about the complication of different pigmentation at different sites on the body and the best accuracy thresholds for the devices.
Most members agreed the premarket clinical study design and standards should be the same for all pulse oximeters used for medical purposes regardless of whether they are used in medical settings or sold over-the-counter for at-home use.
“I think the same standards should be upheld because … pulse ox in the medical setting is one variable taken into consideration in concert with the rest of the clinical picture. But for people at home with a heavy reliance on pulse ox, that may be their single factor in making decisions like do I go to the ER,” said Anne Whitney Brown, M.D., senior director of clinical affairs at the Cystic Fibrosis Foundation.
Members called for clear labeling for products approved for medical use vs. those that are for general wellness and have not received FDA review and approval.
The FDA will take the committee’s input into consideration as it decides on new standards.