By Reuters Staff

NEW YORK (Reuters Health) – A new study provides more
evidence of racial bias in pulse-oximetry results, with Black
and Hispanic people having a higher prevalence of occult
hypoxemia during surgery than white people.

Pigmentation in dark skin has been associated with
overestimation of pulse-oximeter values.

To investigate further, researchers at Mount Sinai in New
York did a retrospective study of more than 46,000 patients who
had anesthesia for surgery patients. They compared
intraoperative arterial oxygen saturation (SaO2) levels with
oxygen saturation measured by pulse oximetry (SpO2), with more
than 151,000 paired comparisons in total.

The primary outcome was occult hypoxemia – defined as SaO2
92% – stratified by
self-reported race/ethnicity.

The researchers found a significantly higher prevalence of
occult hypoxemia in Black (2.1%) and Hispanic (1.8%) patients,
compared with white (1.1%) patients (P

In the multivariable analysis, Black and Hispanic
race/ethnicity were independently associated with occult
hypoxemia, with odds ratios of 1.44 (P=0.006) and 1.31
(P=0.031), respectively.

This is a problem with potentially far-reaching consequences
due to the vital role pulse oximeters play in modern healthcare,
first author Dr. Garrett Burnett of the Department of
Anesthesiology, Perioperative and Pain Medicine at Mount Sinai
said in a statement.

“Although the lack of objective skin pigmentation
information and the retrospective nature of this study may limit
the strength of our findings, we believe it is important to
recognize the limitations of monitoring devices and maintain
vigilance to avoid unrecognized hypoxemia,” he and his
colleagues write in the journal Anesthesiology.

“Based on our findings, it may be prudent to have a greater
index of suspicion for occult hypoxemia if SpO2 is less than 96%
for Black patients and 95% for Hispanic patients (compared with
94% for White patients),” they add.

The U.S. Food and Drug Administration recently issued a
safety communication noting that evidence in the scientific
literature points to “some accuracy differences” in pulse
oximeters between dark and light skin pigmentation (https://bit.ly/3xYJc4d).

The agency is currently investigating the issue and working
with device manufacturers and testing laboratories to better
understand it.

SOURCE: https://bit.ly/3vYlpP5 Anesthesiology, online May 1,
2022.