Incorrect oxygen readings delayed Covid care for dark-skinned patients

CAccording to ovid-19 care, including the distribution of life-saving therapies, oxygen measurements from devices that may not work well in dark-skinned people are significantly inaccurate in black and hispanic patients. I was late. Investigation It was released on Tuesday.Discovery may be one of many reasons Higher Covid-19 mortality rate It is found in color communities throughout the United States.

Widely used Pulse oximeterMeasuring oxygen levels by assessing blood color, Racial prejudice This is because you can overestimate the blood oxygen levels of people with dark skin to make them look healthier than they really are.In a 2020 study comparing oxygen levels measured by the device with measurements taken from “gold standard” arterial blood samples, pulse oximeters 1/3 chance To detect hypoxic levels in black patients rather than white patients.Two months after the report, the Food and Drug Administration issued it. Secure communication Warn patients and clinicians that the device may be wrong in people with dark skin.

The study, published at JAMA Internal Medicine, found that oxygen measurement inaccuracies occurred at a higher rate in Hispanic and Asian patients as well as in black patients than in Caucasian patients, and those inaccuracies affected the real world. Shows that it has caused.This study provided evidence that undetected low oxygen levels lead to delays in black and Hispanic patients with potential life-saving treatments such as remdesivir and dexamethasone, and often to patients. Not receiving any treatment..

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Tianshi David Wu, assistant professor at Baylor College of Medicine and co-lead author of the new study, said: He calls the pulse oximeter the “de facto gatekeeper” of Covid treatment. The low readings of these devices are important criteria for deciding how aggressively to treat a patient. “Probably there were patients who should have received these treatments, and the majority were black patients.”

This study used data from more than 7,000 patients who were seen in the emergency department of the Johns Hopkins Health System in Baltimore or were admitted to one of five hospitals. More than a quarter of them (mostly people of racial and ethnic groups who reached their limits) would have been eligible for Covid-19 therapy before the pulse oximeters recognized the need for care. I found out. They found that black patients were 29% less likely to be recognized for treatment eligibility by the device than white patients, and non-black Hispanic patients were 23% more likely to be recognized for treatment eligibility. I found it low.

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The authors, both pulmonary emergency physicians treating Covid patients, felt many physicians despite concerns about pulse oximeter bias, so measurement inaccuracies were clinically relevant. He said he had an incentive to determine if he was doing it. Raised in the scientific literature for decades — I was unaware of how the inaccuracies of these very important diagnostic devices affect color patients. They said the issue was not part of the standard medical school curriculum.

Ashraf Fauzy, assistant professor of medicine at Johns Hopkins University and co-lead author of the study, said: “The inaccuracy of this pulse oximeter has clinical implications, even more so in racial and ethnic minorities. It’s a systematic failure.”

The study found that pulse oximeters overestimated oxygen levels by 1.2% in black patients, 1.1% in Hispanic patients, and 1.7% in Asian patients. Although they may sound like small differences, oxygen levels are so important to health that many disease treatment protocols, including Covid, dramatically change when small differences in oxygen levels are detected. It may be different.

In the case of Covid, drug treatment is indicated when oxygen levels fall below 94%, but in this study, blood oxygen levels in many patients, despite what the pulse oximeter read, showed that level. It was shown that it was below. “This is a good example of how a relatively small bias in accuracy can have a significant impact,” says Wu.

Researchers found that black patients, whose eligibility for Covid treatment was finally confirmed by pulse oximetry, were one hour behind white patients. (Patients who had never been treated were not included in this account.) Wu said it was not clear if the delay was clinically significant. The authors said more studies are underway to assess whether such delays or lack of access to treatment directly lead to higher mortality rates.

Thomas Valley, an assistant professor of medicine at the University of Michigan, said the study was an excellent addition to accumulating evidence that the inaccuracy of these devices was at great cost. Publication In 2020, he and his colleagues aroused widespread interest in the device inaccuracy of black patients and how bias affects care.Previous studies have undetected hypoxia Continuous organ failure When death In colored patients, but those studies were not specifically performed in Covid patients, as was the case with the new study.

“We’ve been looking for reasons why blacks and Hispanics are more likely to die early in the pandemic,” Valley said. “This seems to be quite disappointing that we had treatments available. Many of those treatments are related to oxygen levels. People are hospitalized or ventilated. The decision to wear a vessel was all based on blood oxygen levels. “

Mr. Valley wants to study how whether returning home from the emergency department or instructing him not to come to the hospital based on his blood oxygen level affected dark-skinned patients. Said. “We always advised,’If your O2 level isn’t low, don’t come to the hospital,'” he said. “I don’t know how much harm it did.”

He wants to get more accurate measurements for light-skinned patients, such as taking painful arterial blood samples when light-skinned patients can use a simple clip-on device for the same measurement. The option said, “In practice, you just replace one bias with another.” Valley, a critical care pulmonologist, called device inaccuracy a major problem in clinical care. “To be honest, sometimes I don’t know what to do in the hospital,” he said.

He questioned the results of pulse oximeters for dark-skinned patients and advised them to consult a doctor, especially if they were feeling sick or had low oxygen levels.

“In my opinion, there is only one fix,” he added. “We need a pulse oximeter that works for black patients as well as white patients.” Many biomedical engineers say that repairing a device is not technically difficult. The problem is getting the device tested and approved and getting the hospital to replace tens of thousands of devices. This is more costly than the consumer version. The FDA will continue to monitor issues and work with device manufacturers to keep consumers up to date when new information becomes available, an FDA spokeswoman told STAT. Although improved devices are available that use more wavelengths of light for better results on all skin tones, Not widely used..

Valley also said in a new study that while Asian patients have inaccurate oxygen levels, they are concerned that they are not experiencing the same proportion of treatment delays as black and Hispanic patients. .. “I think it’s as worrisome as the consequences of pulse oximetry,” he said. “It suggests that we treat people differently.”

The study’s author, Fawzy, said the small number of Asian patients who participated in the study may have led to insufficient statistical power to detect whether Asian patients experienced delays. Said. Increasingly large-scale research is needed on the Asian population. Previous research In contrast to new studies, the results of undetected low oxygen levels found that measurements in Asian patients were more similar to those in Caucasian patients.

According to Mr. Valley, one problem is that race is an imperfect substitute for skin color. Better studies may compare patients by actual skin color rather than by racial group.

Utibe Essien, an assistant professor at the University of Pittsburgh School of Medicine and working on the issue of equal access to treatment, has long postponed dealing with inadequate oxygen measurements in some races and ethnic groups. Get and use the correct device. He said he was dissatisfied with the lack of investment and urgency to address potentially life-and-death issues, affecting a very large proportion of the population.

“It’s not just about providing fairness,” Essien said. “It actually affects the treatment.”

Bias pulse oximetry Race- and ethnic-based cutoffs A group led by Valeria Valbuena, a general surgeon at the University of Michigan, has access to transplants and other treatments for many patients in the group who have reached their limits as doctors underestimate the severity of the disease for lung and kidney function. I wrote that I tried to limit it. Editorial with new research.. Valbuena urges hospital systems and clinicians to address the “historical negligence” and “reduced concern” of colored patients by insisting on the purchase of effective medical devices for all patients. I did.

“The decision to do nothing about a defective device is a human decision,” the author writes. “And it can and needs to be fixed.”