Oximeters may not always give accurate reading on dark skin: Study

US Food and Drug Administration (USFDA) has warned that Oximeters may not always give accurate measurement of oxygen levels in blood if used for patient with 'skin pigmentation'. This almost entirely translates to Oximeters not providing accurate results 100 per cent of the time for patients with dark skin. USFDA has issued a warning in this regard. It uses a study published in The New England Journal of Medicine. The study has been carried out by researchers from University of Michigan Medical School.

Oximeters are devices that are typically attached to fingertips of patients. Oximeters are non-invasive in their measurement of blood oxygen levels. In times of coronavirus pandemic, use of Oximeters has increased many times around the world. Drop in blood Oxygen levels may indicate that a person may be infected by COVID-19 virus.

The study carried out by researchers from University of Michigan compared Oxygen readings from Oximeters to those obtained by a more accurate method called Arterial blood gas. These 'pairs' of readings, taken from 10,001 patients were analysed. The patients had White as well as Black patients. It was found that occurrence of wrong reading of blood oxygen levels was three times more in Black patients than it was in White patients. In these patients, Oximeters gave a wrong reading about blood Oxygen levels being normal whereas it was not so.

Based on this study, USFDA has issued a warning that "pulse oximeters have limitations". It has then advised health care providers to supplement their readings with data from other tests and other information that may forthcoming during the examination of the patient.