Device used to measure blood oxygen may give misleading information to black patients, study finds

The fingertip device that measures a person’s blood oxygen saturation level may give blacks false readings more frequently than whites, according to a recent study.

The results were noted in a Dec. 17 report published by the New England Journal of Medicine.

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

He found that the readings from the device, known as a pulse oximeter, were sometimes inaccurate compared to a test that draws blood from a person’s artery.

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

The study notes that the results are alarming given the number of people who can rely on the devices to monitor blood oxygen levels during the coronavirus pandemic.

“Given the widespread use of pulse oximetry for medical decision-making, these findings have major implications, especially during the current coronavirus pandemic in 2019,” he says. “Our results suggest that using pulse oximetry to triage patients and adjust supplemental oxygen levels may place black patients at increased risk for hypoxemia” or low blood oxygen levels.

Dr Michael Sjoding, pulmonologist and lead author of the study, told National Public Radio that he was first alerted to the problem after his hospital at the University of Michigan began receiving an influx of mainly Black Covid-19 patients.

He said he noticed that pulse oximeter results gave misleading information “more often in black patients.”

“Basically about three times as often,” he said. “It doesn’t happen often, but if you think about how often these measurements are taken, if it’s wrong 12 percent of the time, I’m afraid it may have a real impact,” Sjoding added.

A pulse oximeter works by projecting a red light through the fingertip.

The doctor said he suspected that the color of a person’s skin could be the source of this misleading information, as the color of the light used in the device can be absorbed by the pigment in the skin, NPR reported.