Some Patients Are Not Receiving Enough Oxygen in US Hospitals-Here's The Shocking Reason

Many black patients under care in US hospitals are receiving less oxygen than they should due to a manufacturing fault in their pulse oxymeters. These devices, designed to detect blood oxygen levels and pulse, show faulty readings for people with darker skin tones. Notably, the problems with these measurement devices have been known for decades but they only got attention during the COVID pandemic. It was then that the Food and Drug Administration (FDA) issued draft guidance for manufacturers to drastically expand the skin tone varieties when testing their devices and how they work equally for all skin pigments.

"The Food and Drug Administration doesn't approve or authorize all pulse oximeters on the market. Devices marketed for general wellness among hikers, cyclists or other athletes who might want to estimate their blood oxygenation, for example, aren’t regulated and should never be used to diagnose or monitor health problems," the FDA said in a statement.

Why Are The Pulse Oximeters Showing Faulty Readings?

The most accurate way to test whether a person has normal oxygen levels is through an arterial blood draw, which involves inserting a needle into a person's wrist to collect blood. While painful, this method provides doctors with essential clues about how well a person's lungs are functioning.

In the 1980s, the pulse oximeter was introduced as a painless alternative to the aforementioned. The device shines infrared light through the fingertip, with a sensor on the other side measuring how much light passes through. The device then calculates the blood's oxygen saturation level. However, since the device relies on measuring the amount of light passing through, the light can also be absorbed by melanin, the pigment in the skin, which may affect its accuracy.

Renewed Attention To Discrepancies In Pulse Oximeter

Dr Thomas Valley and his colleagues at the University of Michigan brought renewed attention to discrepancies in pulse oximeter readings during the height of the COVID-19 pandemic in 2020. As they faced an influx of COVID patients, they noticed a troubling pattern-the vast majority of the sickest patients were Black. "We started to notice that the numbers on the screen for pulse oximeters weren’t matching what we were seeing in arterial blood," Dr Valley later said. "We would go from room to room and see that these numbers didn’t look quite right."

Initially, the team believed the anomalies were a result of coronavirus. It wasn't until several months later that a light bulb went off, Valley explained, adding that it wasn't a COVID problem but a colour of skin problem.

In December 2020, Valley and his team published their findings on racial biases in pulse oximeter readings in the New England Journal of Medicine. This study caught the attention of patient advocate Starr, who used it to alert her doctors to potential inaccuracies in her readings. The faulty pulse oximeter readings for patients of colour could preclude Black patients from being candidates for advanced therapy, researchers said. For instance, unreliable readings might prevent Black patients with heart failure from qualifying for potentially lifesaving procedures such as heart pumps or transplants.