U-M study finds Pulse Ox devices less accurate in patients with darker skin

Accuracy could be an even bigger problem with the home Pulse Ox devices

If you or a loved one has had a case of COVID, you may be familiar with the Pulse Ox device to check how much oxygen you have in your blood. It's often the first clue that a COVID patient will need more advanced medical care, but research from the University of Michigan finds these devices are not as reliable for every patient.

DETROIT – If you or a loved one has had a case of COVID-19, you may be familiar with the Pulse Ox device to check how much oxygen you have in your blood.

It’s often the first clue that a COVID patient will need more advanced medical care. Still, research from the University of Michigan finds that these devices are not as reliable for every patient.

A Pulse Ox clips on your finger to monitor oxygen levels but doctors at Michigan Medicine have noticed some patients who appeared to have regular readings were actually in trouble.

“Patients who have darker skin colors were having normal reads in our hospital Pulse Oximeters, but then when we got a blood test to actually test the amount of oxygen in their blood, it was dangerously low,” said University of Michigan Health Dr. Valeria Valbuena.

Dr. Valbuena says that observation inspired U of M researchers to conduct a study, which found black patients were significantly more likely to have an inaccurate reading.

“The Pulse Oximeter works by shining light through your skin, and there are a number of things that can affect how that light interacts with the particles in your blood that carry the oxygen, and one of those things is melanin.” Dr. Valbuena said. “And so patients with darker skin color have up to three times the chances of having an erroneous read on the Pulse Oximeter.”

That could lead to delays in receiving oxygen or other critical care.

“In the long term, we need as a field to push for equitable medical design, so that devices like the Pulse Oximeter and others are tested in a diverse group of patients so that they work just as well for patients of different races, ethnicities, and different genders,” Dr. Valbuena said.

Experts say accuracy could be an even bigger problem with the home Pulse Ox devices.

If you’re having trouble breathing, Dr. Valbuena says you should still seek immediate medical help, even if you use a Pulse Oximeter that gives you a normal reading.


About the Authors:

Kimberly Gill joined the Local 4 News team in November 2014. She was named Personality of the Year in 2009 by the Ohio Broadcaster’s Hall of Fame. She’s also a two-time Emmy winner.

Brandon Carr is a digital content producer for ClickOnDetroit and has been with WDIV Local 4 since November 2021. Brandon is the 2015 Solomon Kinloch Humanitarian award recipient for Community Service.