TMonths after Democratic lawmakers expressed concern over possible racial differences in pulse oximeter readings – which called the issue a matter of ‘life or death’ – the Food and Drug Administration issued a public warning on the devices on Friday, acknowledging that they ‘ have restrictions’.
The warning 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 provided new data underscoring the problem. Recently, researchers at the University of Michigan published a letter in December 2020 in the New England Journal of Medicine finding that oximeter hypoxemia would miss almost three times more than in white patients.
“Be aware that multiple factors can affect the accuracy of a pulse oximeter measurement, such as poor circulation, skin pigmentation, skin thickness, skin temperature, current tobacco use, and the use of nail polish,” reads the FDA warning.
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There is no explicit mention of racial differences in the accuracy of the devices, which is likely to disappoint clinicians and patients who want to draw attention to the problem.
“It is noticeable that the word ‘race’ or ‘race’ is not mentioned in the FDA communication,” he said. Thomas Valley, a doctor of lung critical care and an author of the NEJM letter. ‘At the same time, what we found was a difference between black and white patients. We do not know exactly why the difference existed, we assume it is skin colored. ”
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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 production of oxygen. In hospitals, the devices play a critical role in making patient care decisions. And late last spring, after several practitioners suggested that the devices could be useful to have on hand at home (similar to the way one wants to keep a thermometer in the drug closet, for example), the home versions of the devices started flying . from the pharmacy shelves and quickly sold out on Amazon and other online sites.
But the December article – and its reference to a series of earlier studies documenting the same problem, including one published in 2005 – raised alarm among researchers and clinicians, who said they were frustrated to hear that the case has not been addressed in a substantive manner 15 years.
“Not having confidence in the accuracy of the number, and being dependent on a device that may be biased towards a certain population, is really worrying,” said Utibe Essien, a physician and assistant professor of medicine. at the University of Pittsburgh School of Medicine. , told STAT earlier this month.
In response to these concerns, William Maisel, director of the product evaluation and quality office at the FDA’s Center for Devices and Radiological Health, told STAT the agency is examining the available data and will consider further studies if necessary. He said the FDA is generally confident that oximeters in the hospital are very accurate, but added that the same may not apply to devices sold online and in drugstores, which the agency does not review or approve.
Michael Sjoding, a pulmonologist at Michigan Medicine and an author of the NEJM letter, said he was pleased the FDA emphasized the importance of not relying too much on pulse oximeters to make medical decisions in his statement. However, he added that he was of the opinion that the absence of an explicit mention of race was a ‘missed opportunity’.
‘Gdue to the limitations of our article … I suspect the FDA wants to be fairly vigilant in their messages about racial differences in the accuracy of the pulse oximeter, and focus more on the issue of pulse oximeter inaccuracy in general, ” he said.