Why It Matters: Readings influence patient care.
Pulse oximeter readings are routinely used and help inform doctors in shaping medical care for any number of diseases, including heart failure, sleep apnea and breathing conditions. A normal reading for a patient in good health should be a blood oxygen saturation level of about 95 percent or higher. If the readings are falsely high, patients may look fine on paper — but they may not get the level of care they need.
The patients in the study released Thursday in JAMA Network Open are what the researchers expected to achieve the best: Their doctors saw the need to take more accurate measurements of their blood oxygen levels. (Most patients who read the fingertip are never double-checked by drawing blood.)
Patients with a fingertip pulse-oximeter reading of 94 percent or more but blood tests showed lower levels were considered to have unrecognized need for Covid therapy. Black patients were found to be nearly 50 percent more likely than white patients to have their condition undiagnosed. Hispanic patients were 18 percent more likely than white patients to have unrecognized need.
Patients with unrecognized needs, regardless of race, experienced delays of about an hour that translated into a 10 percent higher risk of delayed Covid treatment. They were also more than twice as likely to be readmitted to the hospital.
The new study excluded patients whose oxygen levels may have mistakenly appeared normal by a pulse oximeter but had no follow-up blood tests, and may have been sent home even though they were seriously ill. .
“That’s the patient population we’re really concerned about,” said Dr. Ashraf Fawzy, a study author who is a Johns Hopkins assistant professor and intensive care physician.
Background: Disadvantages can lead to significant differences in health.
The Food and Drug Administration has approved the type of fingertip pulse oximeter used in hospitals and sold by prescription. The agency issued a safety communication about the flaws in early 2021. And it held a hearing in the fall before an expert panel, with researchers outlining studies pointing to the role the device could play in deepening disparities in health for patients with darker skin tones.
The agency approves those devices through its so-called 510(k) program, which eliminates similar devices — with some more investigation. The program has been criticized over the years because the standards for clearing devices are generally lower than those for the agency’s approval of new drugs.
During a hearing in November, the FDA noted that pulse oximeters sold over the counter are subject to less oversight, prompting agency advisors to issue warnings to consumers who use the devices to measure their own respiratory health.
What’s Next: The FDA has promised more testing.
The FDA has not disclosed a big change on how it handles pulse oximeters, but said Thursday it planned to publish a discussion paper to get feedback on the issue and convene another meeting with experts to discuss potential strategies.
“It is a high priority for the agency to ensure that oximetry device performance is consistent and accurate for all US patients,” the agency said in a statement.
Some work has also started design a better Pulse oximeter.
However, for now, said Dr. Fawzy that doctors should trust their general impression of a patient’s condition when considering a pulse-oximeter reading.
“It’s important for us to recognize that this device may lead to clinical decisions that are inaccurate,” he said, “or that we may not be treating certain people or not recognizing their needs.”