Dangerously wrong oxygen readings in dark-skinned patients spur FDA scrutiny

Studies have shown racial bias in the use of oxygen measuring devices, as well as the dangers of inaccurate blood oxygen readings in dark skinned patients. The US Food and Drug Administration has summoned its expert advisors to review the problematic devices.

The FDA announced on Thursday that it would hold a meeting on November 1 to discuss pulse oximetry. The agency renewed its focus on the safety warning it issued in February of 2021.

A study from December 2020 highlighted the racial bias of pulse oxi meters. The global spread of a respiratory disease with a symptom of breathing difficulty caused pulse oximeter usage to soar. The study found that pulse oximeters were more likely to miss dangerously low blood oxygen levels in black patients than in white patients.

The racial bias was shown to pose a risk to dark-skinned patients during the Pandemic and beyond. It wasn't the first study to report the biases. The racial disparity has been noted by researchers for many years.

Dubious devices

The first pulse oximeters were developed in the 1970s and have since become a staple in patient care. They estimate blood oxygen saturation by looking at the relative absorbance of two wavelengths of light beamed into the finger.

Light-skinned patients were the focus of the testing and calibration. Dark-skinned patients may have high levels of skin pigment that can affect the absorbance measurement. Dark-skinned patients tend to have lower oxygen saturations than other people.

During the Pandemic, the dangers of those faulty readings were realized. In a study published in May, it was found that the overestimation of SpO 2 in black and Hispanic patients with COVID-19 caused delays in care. Some patients had their eligibility for treatment denied because of the faulty readings. The study was conducted by researchers at the University of Baltimore.

A study done in Boston in July found that darker skinned patients in intensive care who had inaccurate pulse oximeter readings ended up getting less supplemental oxygen. Researchers in Michigan looked at the records of more than 30,000 patients at the Veterans Health Administration over the course of five years. Black patients were more likely to have hypoxemia. There is a link between hidden hypoxemia and an increased risk of death.