Health Equity

October 11, 2022

Skin pigment affects oxygen monitor

Black patients in the ICU were more likely to have low or high blood oxygen levels than white patients, even when a pulse oximeter indicated 92-96% oxygen saturation, Vanderbilt researchers found.

Critically ill patients can receive invasive mechanical ventilation to stabilize oxygen levels. A pulse oximeter device is secured on the finger to monitor oxygen levels during ventilator use. 

Skin pigmentation may affect the accuracy of the device, leading to episodes of hypoxemia, low blood oxygen levels, or hyperoxemia, high blood oxygen levels, even when the device detects levels in a normal range. 

Kevin P. Seitz, MD, MSc, Matthew Semler, MD, MSc, and colleagues evaluated the relationship of race to incidence of hypoxemia and hyperoxemia in 1,024 patients receiving invasive ventilation in the medical ICU between July 2018 and August 2021. 

The researchers discovered that when oxygen saturation was between 92-96%, Black patients had an incidence of hypoxemia three times greater than white patients. These patients also had a twice as likely incidence of hyperoxemia. 

Their findings, reported in the journal Critical Care Explorations, highlight the need to redesign pulse oximeters to accurately measure Sao2 (arterial oxygen saturation) for all patients.

Co-authors were Li Wang, MS, Jonathan Casey, MD, MSc, Shannon Markus, MD, MPH, Karen Jackson, MD, Edward Qian, MD, Wesley Self, MD, MPH, and Todd Rice, MD, MSc.

The study was supported in part by National Institutes of Health grants HL153584, HL087738, HL123009, and HL143053.