Study: Pulse Oximeters Give More False Readings to Black Patients

Study: Pulse Oximeters Give More False Readings to Black Patients Study: Pulse Oximeters Give More False Readings to Black Patients (Dreamstime)

By Marisa Herman | Thursday, 17 December 2020 04:56 PM

Black people are more likely to get a false reading from a fingertip device that measures blood oxygen saturation levels, also known as a pulse oximeter, NBC News reports.

According to a recent study published by The New England Journal of Medicine, readings from the device were sometimes inaccurate when compared with a test that samples blood from a person's artery. The problem presented itself more in Black patients.

A team studied more than 10,000 pairs of measurements from adult hospitalized patients receiving supplemental oxygen at the University of Michigan Hospital as well as more than 37,000 pairs from patients in the intensive care units at nearly 200 other hospitals.

"In the University of Michigan cohort, among the patients who had an oxygen saturation of 92 to 96 percent on pulse oximetry, an arterial oxygen saturation of less than 88 percent was found in 88 of 749 arterial blood gas measurements in Black patients and in 99 of 2,778 measurements in white patients," the report states.

The report notes that its findings are alarming as many people are relying on the devices to track blood oxygen levels amid the coronavirus pandemic.

"Given the widespread use of pulse oximetry for medical decision-making, these findings have some major implications, especially during the current coronavirus disease 2019 pandemic," it states. "Our results suggest that reliance on pulse oximetry to triage patients and adjust supplemental oxygen levels may place Black patients at increased risk for hypoxemia," or low blood oxygen.

Dr. Michael Sjoding, a pulmonologist and lead author of the study, told NPR that he was first made aware of the problem after the hospital at the University of Michigan started to receive an influx of mostly Black coronavirus patients.

He said he noticed the pulse oximeter gave out misleading information "more often in patients who were Black."

"Basically, about three times as often," he said. "It's not happening a lot, but if you think of how often these measurements are taken, if it's wrong 12 percent of the time, I worry that could be really impactful," Sjoding said, adding he thinks a person's skin color could be the reason behind the misleading information.

The device works by shining a red light through the tip of the finger. He told NPR the color of the light used in the device can be absorbed by skin pigment, which may be altering the results.