Renal Failure???

Yes, that’s right. Renal Failure.

You may be asking yourself, “Why are we talking about renal failure?”

You may also be asking yourself, “Has Doctor B lost her marbles? COVID-19 is a pulmonary disease!”

You may also be thinking, “I just learned all this stuff about the lungs and now I have to learn about the kidneys, too?”

Good news! I haven’t lost my marbles. Other good news (yes, its good news!), you do need to learn about the kidneys if you plan on treating patients with COVID-19. You also need to learn about the kidneys if you are treating patients with heart failure, diabetes, cancer, and pretty much anything else. So why not do it now?

Let’s get to the specifics…

What does renal failure have to do with COVID-19?

Sometimes our immune system and body are completely amazing and do exactly what they need to. And other times they just don’t. And in these other times our body has to make pretty serious decisions to ensure our survival.

Our body is basically playing “Governor of the State of Our Body”. It has to choose what is and is not essential when it comes to jobs performed in the body. And when the cytokine storm hits and organs start to shut down, your body has to pick and choose what to keep to help you survive.

The lungs are failing. That is the site of the infection. So, although the body would likely save those if it could, it just can’t. The brain and heart are next. It will do what it can to save these vital organs. That means lesser organs, like the liver (yep, we see elevated liver enzymes in COVID patients due to liver dysfunction and failure) and kidneys, get deemed “nonessential”. I realize that’s like saying that we keep the peanut butter but jelly has got to go…

There are other schools of thought that the virus may be attacking the kidneys directly via the ACE2 mechanism through which it attacks the lungs, but we don’t have much evidence for this yet.

So, ultimately, the body says, “buh-bye” to the kidneys and they start to shut down. Take in to account that this is a pretty critical problem because the lungs are filling with edematous fluid from the cytokine storm. This fluid is stuck in the lungs because the alveoli have been damaged so the diffusion that needs to happen to get this fluid out via the blood stream is difficult. The blood stream would carry this extra fluid to the kidneys for filtering but it can’t do that now either. And we end up in multiple organ failure on a ventilator AND hemodialysis (HD).


Even though I write this blog based on cardiopulmonary rehab and interventions, I actually do a pretty large amount of work with and for patients who undergo hemodialysis. These systems are so intricately intertwined that it isn’t a far cry. But we can talk more about that in a different post.

For now, you need to know that patients who develop End-Stage Renal Disease (ESRD), or the kidneys shutting down, must undergo hemodialysis (or peritoneal dialysis) to help filter out all the bad fluids their kidneys no longer can handle.

One article suggests that up to 30% of patients in the ICU with COVID-19 have kidney failure necessitating hemodialysis. Just like we can medically and mechanically assist the lungs in their function using a ventilator, we can do the same for the kidneys using a dialysis machine or dialyzer. However, this process, just like being on a ventilator, comes with many of its own complications. These include:

  • Hypotension
  • Fluid Overload OR Dehydration
  • Infection (due to fistula/port access)
  • Muscle Cramps
  • Chills
  • Anxiety and Depression
  • Severe Fatigue

UPDATE: April 20, 2020 NPR article

I do some research on interventions for patients who have ESRD and what is overwhelmingly clear is that these patients need to be exercising DURING the hemodialysis transfer. Exercise, even to a lower intensity (40% HRmax) decreases hypotensive response, elevates body temperature (HD patients are ALWAYS cold!), and reduces fatigue. These are just a few of the many positive effects of exercise performed during HD. And let me tell you, this evidence isn’t new by any means. I’m talking over 40 years worth of evidence in my literature review.

So, now for the “how.” The basics are this:

  • 10-30 minutes of continuous exercise (alternating intervals are perfect!)
  • 40-60% HRmax
  • Once in the first hour and once in the second hour of HD treatment
  • Three days per week (that’s every dialysis session)
  • ANY mode of exercise is great, but supine cycling has the most evidence and is safest, especially for patients who are in the more acute setting.
  • Patients can lay, sit, or stand during dialysis based on what you deem safe as long as they do not occlude or obstruct their access site.

I actually provide HIIT for these patients in the sub-acute setting and home setting targeting 50-70% HRmax using body-weight and resistance exercises. It is very well received, has good compliance, and shows significant increases in QOL. Fighting the fatigue in long term ESRD is the toughest part. But fighting COVID-19 is tough, too, and we are doing that pretty well! If you want some really recent research, check out the work of colleagues in Oslo: Birgitta’s research!

HD may be a long term need or a short term need until their kidneys can recover. But, just like with our damaged alveoli, some people may not be able to heal their kidneys. Patients may be returning home with ongoing ESRD and will continue to need dialysis. Keep them moving, keep them active, start exercise interventions as soon as possible to prevent the deleterious effects of HD treatment.

It is also important to note that HD provided in the acute setting is actually a bit different. This is called Continuous Renal Replacement Therapy (CRRT). This is HD that runs continuously for 24 hours per day. So the above parameters don’t apply. However, you will likely not be providing HIIT to patients in the ICU setting! Getting them sitting EOB and walking short distances will probably be more likely interventions.

Hemodialysis is life-saving, but it is also life-altering. So is well-prescribed exercise! You can make the difference! If you have more questions about providing exercise during HD, please put them in the comments!!! I’d love to chat about that!

Do you work with patients who undergo hemodialysis or peritoneal dialysis? Tell me about your experiences trying to apply exercise in the comments!

Pressure… Pushing Down On Me…

Breathing. I can’t stress it enough. If you’re not breathing, you’re dead… or in a lot of pain… either way, it’s not good. So breathe! In my practice, I work with a lot of different types of patients with a wide variety of conditions and comorbidities, but they all have one thing in common: they…


WHILE WE WAIT FOR THE NECT CHAPTER OF DIABETES MANAGEMENT, LET’S KEEP TALKING ABOUT INCONTINENCE Chronic management of urinary incontinence can lead to many issues like infection and hospitalization if it doesn’t account for fluid balance! Let’s talk I’s and O’s! #physicaltherapy #incontinence #chronicdisease


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Mogul, F. (2020). Shortage of dialysis equipment leads to difficult decisions in New York ICUs. Health News from NPR. Retrieved from

Nilsson, B. B., Bunæs-Næss, H., Edvardsen, E., & Stenehjem, A. E. (2019). High-intensity interval training in haemodialysis patients: a pilot randomised controlled trial. BMJ open sport & exercise medicine5(1), e000617.

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