Should You Really Have a Pulse Oximeter at Home?

It’s fair to say that the novel coronavirus pandemic has changed the way people shop—and also the items they shop for. There has been a shortage of things one might expect: toilet paper, disinfectant wipes, and thermometers. But, there are other—more surprising—items like yoga mats, yeast, and, more recently, pulse oximeters.

So, what, exactly, is a pulse oximeter?

It’s an electronic device that clips onto a patient’s finger to measure heart rate and oxygen saturation in his or her red blood cells—the device is useful in assessing patients with lung disease. Pulse oximeters started to fly off store (and online) shelves when people learned that low oxygen saturation levels can be a sign of COVID-19.

The logic is that shortness of breath, a symptom of the disease, may not be easy—or even possible—for a person to reasonably self-assess. What’s more, doctors report that some COVID-19 patients suddenly develop a condition called “silent hypoxia,” where people look and feel comfortable—and don’t notice any shortness of breath—but their oxygen levels are dangerously low. It happens to patients both in the hospital and at home, but it is a particular problem in the latter case because the symptom may indicate severe COVID-19-related pneumonia, requiring a ventilator. That’s why some people may want or need to monitor their oxygen saturation levels at home.

There is debate among doctors about whether or not people need a pulse oximeter in their medical supply kits at home. “In normal times, unless a patient has true lung disease, there is no need for them to use pulse oximetry monitoring,” says Denyse Lutchmansingh, MD, a Yale Medicine pulmonologist. But these aren’t normal times. The American Lung Association advises against buying pulse oximeters unnecessarily and recommends people focus their awareness on other COVID-19 symptoms. However, in a recent New York Times opinion piece, an emergency physician from New Hampshire said if resources were directed toward earlier detection of silent hypoxia, doctors could do more to keep those patients off ventilators.

There are additional factors to consider, says Dr. Lutchmansingh. One is that knowledge of the virus is rapidly changing, which means advice can shift, as it did when the Centers for Disease Control and Prevention (CDC) changed its face mask recommendation in April to one that urges people to start wearing cloth masks in public. “We’re working very fast with limited pre-existing data. We are extrapolating a lot based on prior coronavirus infections, like severe acute respiratory syndrome [SARS] and Middle East respiratory syndrome [MERS],” she says.

At this point, Dr. Lutchmansingh says the benefits of pulse oximetry monitoring are most clear among patients who have COVID-19 symptoms such as cough, fever, and shortness of breath. “If you are symptomatic that is a reasonable time to check your oxygen. That is something we’ve been trying to do from an outpatient standpoint,” she says. “We have COVID-19 patients who we are monitoring at home and one of the deciding factors for bringing them into the hospital is their oxygen level.”   

But for people who are young and healthy—and have no COVID-19 symptoms—she questioned the need to buy a pulse oximeter. 

If you do have a pulse oximeter and are checking your oxygen levels, it’s important to know that a level between 95 and 97% is considered normal by the American Lung Association; anything below that would be a reason to call a doctor, and anything under 90% would be a reason to go to the emergency room.

Dr. Lutchmansingh also advises people who plan to use a pulse oximeter to ask a medical professional to guide them. “It’s helpful to know your baseline level,” she says. “If there are changes, a medical professional can talk about what’s causing those changes and take any additional measures to investigate it.” Changes might be related to a non-COVID pulmonary problem that may be undiagnosed, such as asthma or unrelated pneumonia, she says. In addition, your reading may be inaccurate if your fingernails are dirty or you have artificial nails or are wearing nail polish.

As far as which pulse oximeter to buy, “There is no standardization,” she says. “You are buying in good faith.” According to Consumer Reports, prices for pulse oximeters range from $25 to $100, if you can find one, as shortages have been reported. Phone apps and exercise trackers like Fitbits are not the best tools for checking oxygen levels, Dr. Lutchmansingh says. “One can always go the route of ‘something is better than nothing,’ but we don’t know how accurate they are,” she says. “But if you have one of those things [apps or trackers] and the numbers are low, I would still advise that you talk to your doctor.”

There is another consideration—some people stock up on anything that eases their fear and anxiety, says Dr. Lutchmansingh. “There is such wide variance to this disease,” she says, explaining that it’s still difficult to predict who will become severely ill, and it’s understandable that people would want to be prepared for any eventuality. “There is the medical component to this, and then there is the anxiety component. People are scared. If they feel there is some action they can take, some sort of monitoring they can use, it’s hard not to take advantage of it,” she says.

“However, it’s not necessarily helpful for people to buy things just to have them, because there is a difference between gathering data and using data,” she says. “It’s not just information in a bubble. You can get all your numbers, but if you don’t know how to interpret them, all you have are numbers.”

Meanwhile, shortness of breath and low oxygen levels are just two possible symptoms of COVID-19, and it’s important to know all of the symptoms, Dr. Lutchmansingh says. The CDC provides a list of symptoms that could appear anywhere between 2 to 14 days after exposure to the virus that causes COVID-19. That list includes cough, fever, shortness of breath, difficulty breathing, chills, repeated shaking with chills, muscle pain, headache, sore throat, and loss of taste or smell.

Patients and members of the community who have questions can call the Yale Medicine/Yale New Haven Health Call Center COVID-19 hotline at 203-688-1700 (toll-free, 833-484-1200). 

Click here to read about a philanthropic gift of 100 wearable pulse oximeters to the Yale Medicine Department of Internal Medicine.