FDA issues alert on ‘limitations’ of pulse oximeters, which have accuracy problems with darker skin personsth

FDA issues alert on the 'limitations' of pulse oximeters Experts and lawmakers have expressed concern about potential racial disparities in the readings of pulse oximeters. Erin Brodwin STAT

Two months after Democratic lawmakers expressed concern about potential racial disparities in pulse oximeter readings — calling the issue a matter of “life or death” — the Food and Drug Administration on Friday issued a public warning about the devices, acknowledging they had “limitations.”

The alert comes decades after researchers first identified potential inaccuracies with the devices when used on people of color and months after a series of new studies produced fresh data underlining the problem. Most recently, researchers at the University of Michigan published a December 2020 letter in the New England Journal of Medicine that found oximeters were nearly three times as likely to miss hypoxemia in Black patients compared with white patients.

“Be aware that multiple factors can affect the accuracy of a pulse oximeter reading, such as poor circulation, skin pigmentation, skin thickness, skin temperature, current tobacco use, and use of fingernail polish,” the FDA’s alert reads.

It does not explicitly mention racial disparities in the accuracy of the devices, likely disappointing clinicians and patients who have sought to draw attention to the issue.

“It’s noticeable that the word ‘race’ or ‘racial’ is not mentioned in the FDA communication,” said Thomas Valley, a pulmonary critical care physician and an author of the NEJM letter. “At the same time, what we found was a difference between Black and white patients. We don’t know exactly why that difference existed, we presume it to be skin tone.”

Pulse oximeters, which measure oxygen levels, have emerged as a particularly useful clinical tool amid the Covid-19 pandemic because of the way the virus interferes with the body’s natural ability to process oxygen. In hospitals, the devices play a critical role in making decisions about patient care.

And late last spring, after several practitioners suggested the devices could be helpful to have on hand at home (similar to the way one might want to keep a thermometer in the drug cabinet, for example), at-home versions of the devices began flying off drugstore shelves and rapidly selling out on Amazon and other online sites. ...