Study co-authored by U of M doctors finds pulse oximeters not as accurate in non-white patients
CBC News | Posted: August 3, 2022 11:27 PM | Last Updated: August 3, 2022
Research found medical device underestimated how much oxygen Black, Asian and Hispanic patients need
A recent Harvard and MIT study co-authored by a pair of University of Manitoba doctors shows that the pulse oximeter may not accurately measure how much oxygen Black, Asian and Hispanic patients need when compared to white patients.
The study, led by researchers at Harvard and MIT, was conducted to determine if there are racial and ethnic disparities in how oxygen is administered to patients due to inconsistent pulse oximeter performance.
Looking at data from patients admitted in intensive care in Boston between 2008 and 2019, it found that the oxygen levels of Black, Asian and Hispanic patients were overestimated by these devices.
"So, a higher level reading, but a lower level of blood oxygen as measured by a blood gas. And that was a relatively new finding," said Dr. Barret Rush, an assistant professor of critical care at the U of M and one of the co-authors of the study.
"Then we correlated that with a less supplemental oxygen administration in the ICU, which is an evidence of disparity of care based on erroneous technical information."
A pulse oximeter is the device that clamps onto a patient's finger and monitors the oxygen level in the blood.
The device was developed in the 1970s and mostly tested on healthy white male patients. Scientists have known for decades that pigmentation, such as skin colour or nail polish, can affect pulse oximeter readings.
However, this study is the first to document the impacts on patient care in finding that non-white patients actually received less oxygen than they needed as a result, said Dr. Jennifer Ziegler, a critical care fellow at the U of M who also worked on the study.
"We were very surprised by this finding and I think it has a lot of implications moving forward into how we use these devices," she said.
"These devices are in all doctor's offices, emergency rooms and clinics, and so it is a very significant finding that there are disparities in the care received based on this reading."
In the short term, the findings will hopefully make health-care providers more aware of the disparities, Rush said, but in the long term, these devices will have to be redeveloped.
That work is already underway, and the study's researchers have already been in contact with several biotech companies in the U.S. that are looking to do this, he said. But because the devices are so common, it will be a monumental effort to replace them, he added.
Rush said efforts are also underway to replicate this study in Canada, specifically looking at Indigenous patients.