The British public health service (NHS) on Saturday 31 July revised its guidelines for the use of pulse oximeters, stating that these devices used to measure blood oxygen levels in Covid-19 patients can give “misleading readings” for dark-skinned patients.
In a statement, the NHS explains that the change comes after a study in April by its Race and Health Observatory, which found that pulse oximeters sometimes” amplify “blood oxygen levels for darker-skinned people,” leading to a ” misleading reading.”
Pulse oximeters, often used at home to monitor for possible degradation, work by sending a light through the skin to measure the amount of oxygen in the blood, says the NHS.