Cramping on dialysis

When does someone cramp on dialysis?

Based on my experience, I have seen two kinds of situations when someone cramps during dialysis:

- When the rate of fluid removal is too high
- When too much fluid is removed

What's the difference between the two, you might wonder? There is. Let me explain.

My dry weight is 79 kgs. Dry weight for the uninitiated, is the body weight when there is no excess fluid in the body. Why might there be excess fluid in the body? For the horribly uninitiated, when the kidneys don't work, fluid builds up in the body because the kidneys do not remove it.

So, my dry weight is 79 kgs. Let's say I put on about 3 kgs as a result of drinking too much water. Now the goal of dialysis usually is to come back to your dry weight. So, ideally I must remove 3 liters of water (because a liter of water weighs about a kilogram) to come back to my dry weight.

If I dialyze for 4 hours, I must remove water from my body at the rate of 750 ml/hour which is too high. Studies have shown that when water is removed from the body at a rate greater than about 400 ml/hour, it is too fast. Cramps can happen.

Another possibility is that too much water is removed, even if the rate of removal is 400 ml/hour or less. For example, let's say I did a 9 hour session and tried to remove 3.5 liters of water during the 9 hour treatment. Even though the rate of fluid removal is less than 400 ml/hour, cramps can occur because I will be below my dry weight towards the end of treatment. Basically I am squeezing my muscles of the water needed for them to function. This results in cramps.

That is why proper monitoring of the dry weight is very important. Unfortunately there is no accurate method of determining the dry weight. We have to use indicators like general feeling of well being and the blood pressure to guess the dry weight.

Who said being on dialysis is fun?!


Anonymous said…
Good post, Kamal. As one who suffers leg cramps about every 3rd dialysis run, anything that gives me insite to the cause is valuable to me. My downfall is root beer. I love it! But if I drink more than half a can a day, I pay for it during dialysis. So my kitchen sink drinks as much of it as I do.
Kamal D Shah said…
Hi Dave,

You can have a little extra fluid during the first hour of dialysis. Have you considered daily home hemo?

I visited your blog - really cool template you have there!

Mark Lee, M.D. nephrology said…
Also using low K+ bath (esp. 1 K+ bath) can cause cramping towards the end of hemodialysis due to transient hypokalemia.
Kamal D Shah said…
Thanks for the information Dr. Lee!

Came acrossed your blog looking for answeres for my husband..He goes to dialysis 3 times a week and latley he has been cramping really bad. Mostly his hands and his neck to the point he has a hard time breathing. He has told them about it but they said they don't understand why he cramps. I will read some more of your blog and maybe get some answeres.

Kamal D Shah said…
How much fluid weight does he typically gain between treatments? Maybe, they need to remove less? Maybe his dry weight has increased?

Just some initial thoughts.

Betty Moorhouse said…
Have you tried Quellitall? My local Davita clinic carries it.
Anonymous said…
Hello all

I am fairly new to dialysis. Unfortunately, this last September my two-year battle to keep my kidneys functioning came to an abrupt halt. My first several sessions of dialysis were pain free and without incident. Only recently have i experienced "severe" cramping in my calves, shins and upper thighs. My dry weight is 106 kgs, or at least my dialysis clinic seems to think so. I was told watch my fluid, but honestly if i drank any less i would not be ingesting any water at all. My target is 36-48oz's a day which i have been very conscious of. My dialysis technician told me I might have gained body weight and this could be affecting the over perception of how much fluid I need to remove to get to get to my dry weight. Like I mentioned I am very new to all this. I do keep track of how much weight I gain or lose prior and post of each dialysis session, but how do I determine what is water weight gain and just body fat? Does any body here have any suggestions, tips, or ideas please? Most appreciated

Best regards to all
Kamal D Shah said…
Charles, it is most likely your dry weight. Can you get them to try increasing the dry weight by half or even one kilogram? Another thing to try is to increase the conductivity by 0.1 or 0.2.
Anonymous said…
Hello! god day!!!

My father also experiencing leg cramps during the middle session of his dialysis... During that time, I constantly massage his legs which gives him comfort in a little way... and he sleeps comfortably with that during dialysis... :)
bharathi said…
1kg removed is equal to how many grams sir