Protect yourself from Covid-19’s silent killer
The novel Coronavirus is a bizarre disease, which has baffled the medical community with its unusual pattern of spread, unpredictable clinical course, and its ability to affect almost any part of the human body. Silent hypoxemia, the phenomenon of having dangerously low oxygen levels without patients feeling very ill, is probably its most unique and deadly feature. Fortunately, it is also easy to identify at home — with the right equipment and knowledge.
Every cell in the human body needs a constant supply of oxygen. The lungs transfer oxygen from the atmosphere into the bloodstream, where red blood cells carry oxygen to the brain, heart, and everywhere else. Normally red blood cells are 95–100% “saturated” with oxygen after leaving the lungs, and around 75% after dropping off oxygen in the body’s tissues.
The human body is extrordinarily sensitive to low oxygen levels. A low oxygen saturation, usually from diseases which damage or inflame the lungs, is usually obvious even without scientific measurement — patients feel awful. The silent hypoxemia of Covid-19 is different, for reasons we don’t fully understand. Patients can have oxygen levels in the 80s before they feel ill — which means that even a slight worsening can be fatal, and which probably accounts for many of the deaths at home from Covid-19.
If you don’t already have a pulse oximeter in your house, you need one. It’s a key part of the LifeKits our team of ER doctors has prepared to help people stay safe and well at home. Check oxygen levels twice a day, and if they are normal (93%-100%) and you don’t have other concerning symptoms you can probably continue to heal at home, while falling oxygen levels are a sign that you need to see a doctor quickly*. Knowing when to go to the ER for Covid is potentially lifesaving — with all that we have learned about Covid-19 over recent months most patients who need hospitalization can be effectively treated, but the first step is knowing that you need medical care.
* If you live at a high altitude where the air is “thinner” your oxygen levels may be naturally lower, and its important to make sure the numbers coming from the oximeter are accurate — if there is not a lot of blood flowing to your fingers because of poor circulation, cold, or low blood pressure, it may give a falsely low reading. This is easier to interpret than it sounds — I will be publishing a video soon that walks you through the details.
