A cautionary tale on buying a pulse oximeter
One morning about two months ago, before coffee had even entered the body, I ordered a medical device that, the day before, hadn’t even been on my radar.
It’s called a pulse oximeter. It’s a simple little gizmo, a little larger than a cigarette lighter, and it measures your blood oxygen levels with infrared light when you clip it on to your finger. As an added bonus, you get your pulse reading, too.
This impulse purchase was prompted by a New York Times piece written by Dr. Richard Levitan, an emergency room doctor who volunteered at the Bellevue Hospital in Manhattan for 10 days at the end of March, to help the oldest public hospital in the U.S. cope with the crush of COVID-19 patients. There, Levitan observed that many COVID-19 patients had “silent hypoxia,” which means they had low oxygen levels, despite the fact that they felt alert and were breathing perfectly normally. By the time patients showed symptoms, the infectious disease could have done potentially irreversible damage to their lungs.
To combat silent hypoxia and start treatment before the damage set in, Levitan recommended monitoring oxygen levels in all patients who tested positive for COVID-19. Despite the fact that I’ve never had a test, I went online and bought one, on the grounds that it was clear we were going to be dealing with this for a long time and my partner is in a high-risk category. If we saw oxygen levels dropping, I reasoned, it would be time to go to the hospital.
Plus, at the time, I was still trying to get my hands on a digital thermometer, which were all sold out. And don’t even get me started on hydrogen peroxide, rubbing alcohol and masks. So, since it was about $60 and still available, I decided to order first and ask questions later.
Turns out I probably should have done it the other way around. First of all, it took a month, since I wasn’t nearly as ahead of the curve as I thought I was. Chris Cuomo, Andy Cohen, “Real Housewives” of various cities and at least one Silicon Valley prepper had already been talking them up as an important part of a COVID-19 survival kit.
Also, it turned out that experts didn’t really think it needed to be a medicine cabinet staple, like a thermometer. It’s really meant more for people with very specific problems or risks.
“Oximeters are super for people with chronic conditions like emphysema, COPD (chronic obstructive pulmonary disease) or lung fibrosis, since it gives them very good guidance on what they can and can’t do,” says Dr. Martin Kolb, director of the division of respirology at McMaster University’s department of medicine. “If those people are exercising and they put an oximeter on, they can see their oxygen levels are low and they need to slow down, or are reassured to keep going or adjust their oxygen. But for an otherwise healthy person it might be overkill.”
Kolb says that the use of oximeters under the supervision of medical authorities is an interesting research question and that, after studies are conducted, it might turn out to be a useful tool in the fight against COVID-19. Several hospitals in Ireland, for example, are sending patients home to self-isolate with wireless pulse oximeters, which medical staff can monitor from the hospital. That means less pressure on hospitals and a lower risk of exposure for everyone. If oxygen levels start to dip, the hospitals can call their patients back in. They also might be useful in longterm-care homes.
“But whether or not the public should be interested in buying these things is a totally different question,” he says, “It’s not something everyone in the public should have at home because you wouldn’t really want healthy people to be monitoring oxygen levels every two hours. This is not what they’re made for.”
My oxygen levels, in case anyone is wondering, are excellent. My last reading was 98 and, for reference, you want to be in the 95 to 100 range. My resting pulse rate probably could use a little work to bring it in line with my pre-isolation vitals. I’m trying to fix that with early morning walks. So maybe it’s good I bought the pulse oximeter after all. And I kind of enjoy checking my oxygen levels every couple of hours.
I asked Kolb, though, if I might be taking one away from a person who really needed it. He said that was certainly a possible scenario, like the situation that came up with the N95 masks, thermometers, rubbing alcohol and hydrogen peroxide that people panicshopped for. Looks like I was a part of the problem, not the solution.
The main point he wanted to get across, though, was that its use as a tool for general members of the public wasn’t supported by any scientific research at this point. That’s a common refrain with basically everything connected to COVID-19, from vitamins D and K to hydroxychloroquine. The pulse oximeter might work. But we just don’t know yet. So any recommendations, especially ones coming from reality TV stars and Silicon Valley preppers, should be taken with a grain of salt.
“Good impactful medical knowledge really needs time,” says Kolb. “And we understand that time is pressing and everyone wants answers yesterday, but it’s just like a good bottle of wine, it takes a few years time to really come into its full flavour and have full impact.
“If you get it out too early you might just have grape juice.”
“You wouldn’t really want healthy people to be monitoring oxygen levels every two hours.”
DR. MARTIN KOLB DIRECTOR OF THE DIVISION OF RESPIROLOGY AT MCMASTER UNIVERSITY