The Food and Drug Administration (FDA) announced recently that it plans to convene a meeting of its Medical Devices Advisory Committee to review concerns about home pulse oximeters. These small devices clip onto your finger to measure your oxygen levels.
The committee will review the accuracy of pulse oximeters, specifically on people with darker skin pigmentation.
Home pulse oximeters have been used widely by people who have or may have COVID-19 to check whether their oxygen levels are dropping. That can be an indicator that a person needs urgent care such as supplemental oxygen.
Are pulse oximeters still considered valuable tools if you're managing a COVID case at home? Experts say the decision to use one warrants a conversation with a healthcare provider.
“We use pulse oximeters frequently in the hospital and they are excellent tools when used in that environment,” Amira Mohamed, MD, an internist and critical care physician at the Montefiore Medical Center, told Verywell. “However, I think prior to being used at home, there should be a conversation with a health provider so that people understand when the use is appropriate, how to use the device, and when and how to report the readings.”
Pulse oximeters use infrared light refraction to measure how well oxygen is binding to your red blood cells. If your blood oxygen level (called oxygen saturation) is too low, it can make it hard for your body to work properly and can put a strain on vital organs like your lungs and brain.
According to the Cleveland Clinic, a normal pulse oximeter reading is between 95% and 100%. The devices have a digital display that flashes the reading. If you have a lung disease such as COPD or asthma, your normal oxygen saturation level may be lower.
Hospital grade pulse oximeters, which have to be approved by the FDA, have been on the market for about four decades. Nonprescription home versions—which are not reviewed by the FDA—came on the market about twenty years ago.
Studies vary on the value of home pulse oximeters for helping patients with COVID-19. For example, a study by researchers at the University of Pennsylvania found that using a pulse oximeter to measure oxygen levels is no better than just regularly asking patients with COVID-19 if they are short of breath.
But the study had a key limitation: All of the enrolled patients had immediate access to health care providers they could contact if they noticed changes in their symptoms or their pulse oximeter readings. A news release notes that for people with COVID-19 who don’t have such immediate access, “self-monitoring with pulse oximeters may still be a reasonable approach until there is evidence to the contrary.”
Similarly, a review of 13 studies that included 2,900 people concluded home pulse oximeters are “pulse oximetry is potentially an effective tool for monitoring deterioration and keeping patients safe at home.” However, further research “should involve more diverse populations, test the system in resource-limited settings, and assess the effect on health outcomes compared with other systems.”
UPenn study co-author Anna Morgan, MD told Verywell that she sees no harm in having a pulse oximeter.
“But if you are otherwise healthy and don’t have one and contract COVID, not having the device is not a reason to panic,” Morgan said. “We learned that the symptom of shortness of breath is telling.”
Before the pandemic, home oximeters were most commonly recommended by doctors to help patients monitor health conditions such as chronic lung disease, shortness of breath, or heart disease, Jonathan Parsons, MD, a pulmonologist at the Ohio State University Wexner Medical Center, told Verywell.
Morgan added pulse oximetry is valuable for COVID-19 patients with underlying lung disease, as well as people who have speech or cognitive difficulties and may not be able to communicate about worsening symptoms.
One key limitation of pulse oximeters, which the FDA will be investigating, is that they may not be accurate in people of color.
A January 2021 study by researchers at the University of Michigan found that Black patients were almost three times as likely as White patients to have low oxygen levels that were missed by pulse oximeters. The researchers said that could translate into as many as 1 in 10 inaccurate readings among Black patients and prompted the February 2021 FDA advisory.
The FDA notes that because pulse oximeters use light that passes through the skin to measure oxygen levels, anything that interferes with the light, like a darker skin tone or even nail polish, can cause inaccuracies.
Parsons said that cold hands can also impair readings.
Oximeter readings are not exact. Your actual blood saturation level may be 2% to 4% higher or lower than what the oximeter reads. As a result, physicians like Parsons urge patients to track several oximeter readings in order to see a trend and not just rely on a single reading.
The American Thoracic Society (ATS) recommends using the heart rate reading that is included on the oximeter to check the device’s accuracy as well. Count your pulse for one minute and compare that to the number you see on the device for heart rate. “If they are the same, you are getting a good signal,” the ATS said.
According to the ATS, the accuracy of your home pulse oximeter can drop if:
If you get an oxygen saturating reading below 95% and have access to someone at home without COVID symptoms, ask them to use the oximeter to see if they get a normal reading.
Ultimately, experts advise simply treating a pulse oximeter as one more tool in your COVID-19 toolbox.
“People who use the devices if they contract COVID-19 should use the readings as just one measure of illness, since we have other indicators that let us know you could be progressing to severe disease,” Parsons said. Troubling breathing, persistent chest pain, new confusion, trouble staying awake, or blue/gray skin and lips are other indictors you should seek emergency medical care.
Pulse oximeters have become mainstays in many homes during the COVID-19 pandemic, but pulmonologists say they should be used as just one tool for assessing symptoms. Doctors recommend taking several readings with your oximeter to follow a trend to report to your doctor, if needed, along with monitoring other symptoms such as shortness of breath and chest tightness.
The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.