Should You Utilize A Home Pulse Oximeter During COVID-19?

The skeptical cardiologist bought a pulse oximeter in May. I’ve long utilized pulse oximeters to monitor the oxygen saturation of my patients in the hospital but never felt the need to have one at home until COVID-19.

I had developed a mild respiratory illness, something which in happier times I would have never thought warranted home oxygen monitoring. With Covid-19, however, we know stricken individuals can precipitously develop low oxygen levels with minimal symptoms (so-called silent hypoxemia) thus I thought it would be prudent to have an oximeter around to monitor my own oxygen levels.

I ended up purchasing the Zacurate Pro Series 500DL Fingertip Pulse Oximeter Blood Oxygen Saturation Monitor with Silicon Cover, Batteries and Lanyard (Royal Black).

The Zacurate 500DL in all its glory

I typically view reviews on Amazon with intense skepticism but I found this review by “Johnny” to be believable and helpful:

In this uncertain Covid era, we learned it was wise to have an Oximeter on hand to measure oxygen levels. As I started to research, I immediately discounted brands new to the market since the onset of Covid-19. Instead, I found two that had many longtime reviews from satisfied users. Two stood out, the Zacurate Pro Series 500DL and the MiBest Oximeter. To my surprise, virtually everything was sold out and I thought I’d struck gold simply by scoring a MiBest after it was almost always out of stock. Once I’d ordered the MiBest and delivery was delayed, I found the Zacurate and ordered it, too. Which is best?

One thing to know up front is that prices are skyrocketing for finger oximeters. They are suddenly hot items on the market. Some quick research showed that the well regarded MiBest had been selling for $30 for years, but at the time of this review its price is fluctuating between $50 and $55 when purchased directly from the company. The Zacurate has always been priced at less than $30 and I felt lucky to score one to compare to the more expensive MiBest.

As it turns out, the Zacurate came a week faster than the MiBest. Simply put, it’s fantastic. Is $30 too good to be true when others can be $50 and up? I truly applaud Zacurate for not taking advantage at this time of tight finances for many in need of reliable health monitoring.

I paid about $40 for the device on Amazon and it arrived in my mailbox 4 days later.

As Johnny points out it appears that around the time of my purchase there had been a bit of a run on pulse oximeters resulting in shortages and some price gouging. This appears to have resolved as you can now buy the Zacurate 500DL on Amazon for 29.99 For those willing to live on the edge this “mystic purple” can be had for $22.83.

Of course, by the time I had the Zacurate in hand, my illness had resolved and I had undergone rapid antigen testing with a negative result for SARS-CoV2 (which doesn’t mean I didn’t have COVID-19.)

Oxygen Monitoring and COVID-19

Does home oxygen monitoring aid in decision-making for individuals with potential COVID-19? Should everyone have one on hand?

Like seemingly everything else related to COVID-19 the answer is not clear.

An article published in Academic Emergency Medicine entitled “Novel use of home pulse oximetry monitoring in covid-19 patients discharged from the emergency department identifies need for hospitalization” concluded that “home pulse oximetry monitoring identifies need for hospitalization in initially nonsevere COVID‐19 patients when a cutoff of SpO2 92% is used.”

A total of 77 patients who presented to an ER in Sweden with nonsevere symptoms and positive COVID-19 testing were sent home. Each patient was given a home pulse oximeter and instructed to record their SpO2 every 8 hours. Patients were instructed to return to the ED for sustained home SpO2 < 92% or if they felt they needed emergent medical attention. 

Below are the (heavily overlapping) O2 courses of the patients who needed to be hospitalized (Figure A) and those who were not hospitalized (Figure B, bottom.)

50% of patients who ended up hospitalized only returned to the ED for incidental finding of low home SpO2 without worsening of symptoms. One‐third (33%) of nonhospitalized patients stated that they would have returned to the ED if they did not have a pulse oximeter to reassure them at home.

This study has a lot of issues which I won’t delve in to but raises the possibility that home oximetry monitoring could better stratify who needs hospitalization and more intense care.

Most pulmonologists seem against the idea. The American Lung Associations Chief Medical Officer, Dr. AndrewRizzo has recommended against home oximetry:

The problem with this is that the pulse oximeter by itself should not be used as the first step in having a patient contact their healthcare provider because the symptoms of COVID-19 normally predate the low oxygen level. It is important to recognize symptoms such as the fevers, cough, malaise, things that seem out of the ordinary, and not just to rely on a number such as a pulse ox to be your first warning that something is wrong. COVID-19 should ideally be recognized before the point of hypoxia. Prior signals should be causing you to call your physician.

Dr. Rizzo says there are many reasons not purchase or utilize a home oximeter but the only one he clearly states is that low oxygen levels might drop for other reasons:

First of all, oxygen levels can drop for other reasons besides COVID-19 such as blood clots, other types of infection, or cardiac issues that can develop. Having a pulse oximeter means you should understand what its role is and what its limitations are, depending on what your health condition is in the first place.

Call me crazy but if your patient calls with a significantly low O2 saturation (perhaps <92%) wouldn’t that point to a serious problem that the physician needs to address irrespective of whether it is COVID-19 or not.

To Buy or Not To Buy

I ended up having another questionably-COVID illness recently.

Throughout the illness I carefully monitored my oxygen levels and my temperature along with any and all symptoms.

I’ll talk more about how I utilized the Zacurate and whether I think everyone should have one in another post.

Until then, please share with me your experiences with pulse oximetry and COVID-19 and how you monitored your questionably-COVID illnesses.

Oximetrically Yours,



7 thoughts on “Should You Utilize A Home Pulse Oximeter During COVID-19?”

  1. I took my Zaccurate to a recent doctor’s appointment, and asked the tech if I could compare to the medical-grade one; she replied “no problem!” Hers read 97%; mine read 98% for a second, and then settled down to 97%. Off course I couldn’t compare its accuracy down in the danger zone. I’ve used it mornings and bedtimes just to get used to what it normally says, which is 98 or 97% almost always. During my walks, when I get a little winded in an uphill stretch, it might drop to 95%, showing that it does respond to changes. The oximeter HR pretty well matches my Apple Watch 4. As you noted, it doesn’t work to use it even while walking – I have to stop and stand still to get a reading at all. With the cooler weather, sometimes my fingers are cold, and I’ll get a low reading – usually with an erratic HR. So overall, this oximeter seems like a handy gadget to have on hand, especially at this low price.

  2. Just got the purple Zaccurate – I couldn’t figure out why it was significantly cheaper then the black one – maybe nobody wanted them? But they are more expensive than a lot of them out there. It seems to be accurate, but I plan to bring it along on next in-office medical appointment to see if I can get a comparison with their instrument. It seems that accuracy can be an issue with these home units. I got it to help me understand the occasional breathless feeling I get (I have afib), not so much as a COVID monitoring device. Please keep up the good work on personal health technology – I’ve appreciated your previous articles on the topic!

    • David,
      Let me know how your comparison goes. I’m doing the same for my Zacurate. You are correct that these devices have not been formally evaluated or approved by a government agency. However, I hope to write soon about a paper which demonstrated that 6 of these nonapproved oximeters were very accurate (although the Zacurate was not in that group.)

      • Will do. Early in the pandemic, this article in wirecutter had a section on home oximeters and their accuracy that cited a few papers, at least one of which I studied and concluded that accuracy could be problem:
        (scroll down to the heading about “How accurate are they?”

        In shopping around, I noticed that many home oximeters were dirt-cheap, so I took your purchase of a moderately expensive one as a suggestion that it could be worthwhile.


  3. Regarding use of POx at home to monitor for deterioration. I have read of cases with asymptomatic hypoxia as the leading sign, not the trailing indicator.

  4. I purchased an oximeter when I learned that patients can be having oxygenation problems before their symptoms seem bad enough to go to the hospital. I subsequently became sick with fatigue and a mild night time elevation in temperature (as measured by an Oura ring) that lasted a little over two weeks. I did have some shortness of breath during the days, especially before an incident when I vomited, but I never saw an oximeter reading below 94-95%. That was the low end of my baseline before I got sick, so I never contacted my doctor. At one point I did get a PCR test that came back negative for SARS-CoV-2. I am suspicious of that result, so will be following up with an antibody test.

    • Sounds similar to an illness I had recently (sans the vomiting.) What O2 sat would have prompted the call to the doctor?


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