In Some Patients With Covid-19, The Blood Potassium Levels Are High
This could be fatal
While taking care of patients with Covid-19, I have noticed something really strange: the blood level of potassium is high. Now, when the kidneys fail, elevated blood potassium can be common, as the kidneys are the main route for the body to get rid of potassium. Yet, in these patients the kidney function is normal, but the potassium level remains high. We make sure they are not getting extra potassium in the IV fluids, and the levels still come back high. This has happened to multiple Covid-19 patients for which I have cared. I have always thought this was a little curious, but then when I did a little more research, I may have found an answer why: perhaps severe Covid-19 acts like ACE inhibitor toxicity, and this may be a marker of severe illness.
There has been a lot of attention on a class of drugs called ACE inhibitors and Covid-19. These drugs are widely used to treat high blood pressure. The reason for all the attention to these drugs is because SARS-CoV-2, the virus that causes Covid-19, attaches to the ACE-2 receptor on the cells in the lungs in order to get into the cells. There was speculation that people taking these drugs are at higher risk for Covid-19 or get worse outcomes with Covid-19. Research has not borne this out.
Yet, given that the virus uses the ACE-2 receptor to gain entry into the cells, if there is overwhelming infection — and/or an overwhelming immune response that causes significant destruction of lung tissue — could this have an effect on the renin-angiotensin system?
I think all of us taking care of Covid-19 patients should share out experiences to help better understand this horrible disease. The more we know about Covid-19, the better equipped we will be to fight it.
What is the renin-angiotensin system?
This is a very complicated system in the body that involves multiple organs — the liver, kidneys, adrenal glands, and the lungs — that regulates blood pressure, electrolyte levels, and other functions. ACE stands for “angiotensin-converting enzyme,” and it converts a hormone called angiotensin I to angiotensin II. The main place of this conversion is the lungs.
Angiotensin II increases blood pressure and it stimulates the production of another hormone called aldosterone, a steroid secreted by the adrenal gland. Aldosterone promotes the absorption of water and sodium in the kidney, and it promotes the removal of potassium from the body through the kidneys.
So, if there is less ACE because the virus is taking up all of the receptors and/or the lungs are being destroyed by the infection and the immune response, there is less angiotensin II and less aldosterone. As a result, you get a high potassium level in the blood without having kidney failure. The way to prove this would be to measure aldosterone levels in the blood, and if they are low, then this may help explain the phenomenon of high potassium. In fact, one of the side effects of ACE inhibitor drugs is high potassium.
Furthermore, if someone overdoses on ACE inhibitors, not only do you get low blood pressure, but you can also get kidney failure and high potassium. Could this be the reason some patients with Covid-19 get shock and renal failure? Could this be acting like ACE inhibitor toxicity?
Of course, whenever we see the high blood potassium level, we treat it immediately, as high potassium levels can be fatal. And, it is true that I have not seen high potassium levels in all of my patients with Covid-19, and assuredly, my experience is just anecdotal and not scientific evidence. Nevertheless, I think all of us taking care of Covid-19 patients should share out experiences to help better understand this horrible disease. And like I’ve said before, the more we know about Covid-19, the better equipped we will be to fight it.