I have read descriptions and seen Dr. Agar’s presentations about the movement of fluid between the three compartments in the body.
Can some of the experts here describe (or point me to some place where I can read about) the movement of fluid between the different compartments when fluid is consumed during dialysis.
What I would like to know is how much fluid can I safely have during dialysis, say the first hour or two hours of a seven or eight hour session with some reasoning about why it is only so much?
Kamal, why are you worried? That is unless you’re going to drink during the first couple of hours every treatment. Since I’m on nocturnal too, I find that I’m less thirsty and drink less than ever before.
Hi Rich, I was just wondering if the water that is consumed gets assimilated into the blood or the other two compartments, the tissues and the interstitial space too in the beginning.
I agree that the fluid intake is less of an issue with nocturnal. This is just something I was wondering about.
My understanding is that when you drink water, some of it is absorbed through your stomach wall and into your bloodstream–but I don’t know how quickly that happens, and that’s what would rate-limit how much it makes sense to drink during a treatment.
We’ve had this discussion a number of times, but no one has really answered your question specifically. I do know one thing. In the years I’ve been on dialysis, I have always had one (.2) or two (.4) 6 oz. drinks on tx. and I have never had a time when the fluid is not removed as evidenced by my final weight. So, two drinks is the most I have had on a tx, but that’s not to say it is not possible to drink more. I never have exceeded that simply because I did not desire more to drink. And one must consider how much is safe to drink on a tx considering ones initial goal, which is another subject that might vary on an individual basis.
I always added the drinks to my goal at the beginning of txs so that the machine was set to remove the extra fluid I drank on txs. I have never done a nocturnal tx, so don’t know if the same conditions would apply. I would think you could test it out by having one drink and seeing if the fluid is removed when you weigh out. Then go up to 2 next tx and see what you get. Notice how your body feels during tx.
Having something to drink on txs has always made txs much more tolerable for me. With being on a fluid restriction, another drink or two is very welcome. With nocturnal there is not supposed to be a fluid restriction, but that is not to say that one can drink all he wants in a day, so having the leeway to drink on tx is a bonus.
I don’t know that the issue is whether you remove the fluid weight, so much as where you remove it from. What you want to do is a treatment that will get at the fluid inside and between your cells–but dialysis can only pull fluid out of the blood. This is where that “waterfall effect” that Dr. Agar talks about occurs. You pull fluid out of the blood. Fluid from inside the cells diffuses through the cell walls and into the interstitial space (between the cells). Fluid between the cells diffuses through the capillary blood vessel walls and into the blood. This is the part that takes time.
So, if I understand it correctly, if you drink fluid while you’re on the machine, you’re pretty much adding it right to the blood, because it is absorbed so easily through the stomach. This cuts down on the capillary refill process that lets you get to the fluid that is “deeper” in the body (inside & between cells), because it dilutes the gradient (difference) that causes the fluid shifts to occur.
When you just drink a few ounces, this isn’t a big deal. But if you drink a liter or two on the machine–as some folks do–you’d be preventing a fair amount of fluid from being removed.
[QUOTE=Dori Schatell;17170]I don’t know that the issue is whether you remove the fluid weight, so much as where you remove it from. What you want to do is a treatment that will get at the fluid inside and between your cells–but dialysis can only pull fluid out of the blood. This is where that “waterfall effect” that Dr. Agar talks about occurs. You pull fluid out of the blood. Fluid from inside the cells diffuses through the cell walls and into the interstitial space (between the cells). Fluid between the cells diffuses through the capillary blood vessel walls and into the blood. This is the part that takes time.
So, if I understand it correctly, if you drink fluid while you’re on the machine, you’re pretty much adding it right to the blood, because it is absorbed so easily through the stomach. This cuts down on the capillary refill process that lets you get to the fluid that is “deeper” in the body (inside & between cells), because it dilutes the gradient (difference) that causes the fluid shifts to occur.
When you just drink a few ounces, this isn’t a big deal. But if you drink a liter or two on the machine–as some folks do–you’d be preventing a fair amount of fluid from being removed.[/QUOTE]
You may be correct, Dori. It would be nice if Prof. Agar could pay us a return visit and rehash this subject a little more. I attended his Part I fluid webinar and very much wanted to attend part II, and know I could of viewed the re-play, but have not done so as yet as I have been totally focused on going to the next level into nocturnal dialysis.
Something I found interesting was that when I advanced to 6x SDD txs from 3x, my dry weight skipped down a K the first week. I never did figure out how that happened- where did the fluid weight go and why?? Also, I was surprised when I posed the question at the first webinar about whether one will lose more fluid weight with nocturnal txs due to the cascade affect that occurs with more time, that Prof. Agar answered no. So, as always, still learning…
Generally the rules I’ve followed been/been taught. This was basically in paediatrics. If your well over the limit of gain, no drink.
A small amount of gain, a couple of 200ml drinks, but this must be added to the loss. Drinks only in the first hour or first part of dx. same applies to food. Less than 2 litres to loose, 1 cup:)
Of course if your doing daily, nocturnal etc this probably doesn’t apply.
I read this with interest. Dori is right - but I would be happy to re-visit ths area in a Q&A session if there seemed interest in it. Maybe Dori could discuss this with me when I am back at the end of the month if she feels there would be value in it.
I think what I am trying to understand is the amount of excess fluid in the blood versus the amount of excess fluid in the cells and the interstitial space. For example, if I have 3 liters of excess fluid in my body, how much of it is typically in the blood and how much in the other two compartments.
This will pretty much dictate the amount of fluid I can have during the first couple of hours of dialysis. I will definitely have to add that amount to my UF goal. No doubt about that. But the key is should the net rate of fluid removal be 400 ml/hour or less or the gross rate of removal?
For example, if I have to remove 3 liters of fluid during an 8 hour session, the rate of removal is 375 ml/hour. My question is - during the treatment, can I have 2 liters of fluid and add that to the UF goal, so that the gross rate of removal is actually 675 ml/hour but the net rate is still 375 ml/hour.
[quote=Dori Schatell;17170]I don’t know that the issue is whether you remove the fluid weight, so much as where you remove it from. What you want to do is a treatment that will get at the fluid inside and between your cells–but dialysis can only pull fluid out of the blood. This is where that “waterfall effect” that Dr. Agar talks about occurs. You pull fluid out of the blood. Fluid from inside the cells diffuses through the cell walls and into the interstitial space (between the cells). Fluid between the cells diffuses through the capillary blood vessel walls and into the blood. This is the part that takes time.
So, if I understand it correctly, if you drink fluid while you’re on the machine, you’re pretty much adding it right to the blood, because it is absorbed so easily through the stomach. This cuts down on the capillary refill process that lets you get to the fluid that is “deeper” in the body (inside & between cells), because it dilutes the gradient (difference) that causes the fluid shifts to occur.
When you just drink a few ounces, this isn’t a big deal. But if you drink a liter or two on the machine–as some folks do–you’d be preventing a fair amount of fluid from being removed.[/quote]
This is a good explanation Dori. Kamal there is one more thing to consider not only will you prevent fluid from being removed you will prevent solutes form being removed. When fluid you drink enters the blood compartment it doesn’t contain the urea/phosphorus/potassium that is in the fluid coming from between the cells. Fluid from drinking would actually dilute the solute concentration in the blood making dialysis less efficient and it would slow the transport of solutes from between the cells/in the cells to the blood compartment where they would be subject to dialysis.
Dr. Agar can clarify this but I think there is a solute waterfall happening at the same time there is a fluid waterfall. The solute waterfall is impacted when the fluid waterfall is slowed by drinking fluids. the faster the fluid transfer then better the solute transfer.
The I don’t understand is the intake of fluids by mouth while on dialysis can effect anything? When a person on dialysis takes too much off or to fast and has issues don’t you get IV saline to bring one back. So taking in fluid by mouth to me seems not have much of in pact outside of adding a kilo or less in body weight?
Bob, please read this thread from start to finish, and I think you’ll get it. The problem is that when you drink fluid on dialysis, it dilutes your blood. This makes the gradient between your blood and the dialysate less effective, so less waste and water are removed during the treatment. Usually when you get saline, it’s only a little bit–much less than some folks would drink.