If a person has a reliable pulse oximeter at home and knows how to use it properly, it may be useful for some people during the coronavirus pandemic.
If a person has a reliable pulse oximeter at home, and knows how to use it appropriately, it may be useful for some people during the coronavirus pandemic. Getting normal oxygen levels can be reassuring, although there is no guarantee that someone won't drop quickly with a respiratory condition. It is possible for a person to have normal oxygen levels, and they can progress rapidly to very low oxygen levels, sometimes life-threatening. There are many factors that come into consideration. One is the quality of the pulse oximeter itself. Second, how well the person uses it. Three different factors artificially raise or lower the pulse oximeter reading, and most importantly, the different factors that relate to the person, such as the underlying medical conditions they have, are they having a sudden exacerbation of their illness?, are they having a new infection that changes things.
Another factor to consider is what is the baseline oxygen level? I have many patients at home who have an oxygen saturation of 90%, and that is their baseline, and that is the best they get. Some of them have oxygen levels lower than that, and require supplemental home oxygen. So, if someone usually has a baseline O2 sat of 100%, and now reads 93%, that is more concerning than someone whose baseline is 93%. And that is another factor to take into account. But in general, when I am on the phone with one of my pulmonary patients, and trying to figure out whether I should send them to the emergency center or urgent care center, I want to know more things, because even if the oxygen level is accurate, it is not the only thing to consider.
When a person with COVID-19 has symptoms, the most common symptom besides fever and cough is shortness of breath. Most people with COIVD-19 pneumonia, but not all, experience shortness of breath. Most people with low oxygen levels, but not all, experience shortness of breath. But there are some people with COVID-19 who do not necessarily feel short of breath, despite having COVID-19 pneumonia, and despite having low oxygen levels.
Does this mean you should rush out and buy a pulse oximeter? Maybe, before you decide whether you would most likely benefit from a pulse oximeter. Let's understand some things about them. A pulse oximeter is a device that measures the oxygen saturation in a person's red blood cells. For most healthy people, oxygen saturation is 100%, which is the highest number you can get. Most devices will clip onto your finger. They work by measuring the amount of light transmitted or reflected through the skin at different wavelengths, and then use mathematical algorithms to estimate the level of oxygen saturation in the blood.
Oxygen readings obtained through a smartphone app are not accurate enough to be relied upon for clinical use. In fact, a study was conducted on this that showed they are unreliable. So although pulse oximeters are not perfect, they are still more accurate compared to smartphone apps. Pulse oximeters are always used in hospitals, and are sometimes used at home for people with underlying health conditions, especially lung conditions, such as COPD/emphysema. Would it be a good early indicator if someone is infected with the coronavirus? Low oxygen levels are unlikely to be a relatively late indicator that a person has coronavirus.
So unless someone is feeling sick, or feeling short of breath, a pulse oximeter is unlikely to be useful in this situation. In other words, for most people, if they feel fine, the likelihood of their oxygen levels being low is very unlikely. So when it comes to the coronavirus pandemic, the purpose of a pulse oximeter, for most people, is best when the person is feeling sick, and they are deciding whether they should go to the hospital or not. Keep in mind that there are conditions that can cause false low readings, such as dark nail polish, artificial nails, very long nails that affect the placement of the pulse oximeter, cold hands, poor circulation, high blood lipids, and last but not least, room lighting can interfere with the light these devices use.
