Oximeter devices that measure blood oxygen levels are less reliable in black patients, according to a report from Reuters.
COVID-19 can cause blood oxygen levels to fall to dangerously low levels, and devices used to monitor these levels are far less reliable in Black patients than in white patients, a large study found. So-called pulse oximeters clip onto a fingertip and pass red and infrared light through the skin to gauge oxygen levels in the blood, which darkens when levels drop. Because pulse oximeters were mostly tested on whites when they were developed, they are calibrated for people with light skin.
Among 1,609 patients studied this year at the University of Michigan Hospital in Ann Arbor, the devices missed low oxygen levels in 11.7% of Black patients compared to 3.6% of white patients. When the researchers studied another 8,392 patients treated at 178 intensive-care units in 2014-2015, they found pulse oximeters missed low oxygen levels in 17.0% of Blacks versus 6.2% of whites.
“Given the widespread use of pulse oximetry for medical decision-making, these findings have some major implications, especially during the current COVID-19 pandemic,” the researchers warned on Wednesday in The New England Journal of Medicine. “Reliance on pulse oximetry to triage patients and adjust supplemental oxygen levels may place Black patients at increased risk.”