Interesting Paper on the Relationship Between Sodium & Fluid Gain / BP

[Stu]

Doing some research for a blog post on coping with fluid restrictions and came across this fascinating article questioning the relationship between sodium intake via diet / dialysis and thirst and blood pressure:

http://ndt.oxfordjournals.org/content/16/8/1538.full

Main takeaways from the paper:

Dialysis and processed foods are the main sources of salt excess.

Low weight gains should cause more alarm than high weight gains.

Weight gain between dialyses bears little relationship to plasma volume or to blood pressure.

Most dialysis patients want to stay alive, and will, within reason, do what is asked of them. Asking patients with severe thirst to drink less than 1 l a day is illogical, inhumane, and should become part of the history of dialysis in the twentieth century. Twenty‐first‐century patients deserve better.

[PrimeTimer]

Interesting article. I notice that altho his fluid intake will be about the same, my husband's BP and weight goes slightly up whenever he eats pre-packaged lunch meats compared to fresh cooked beef with no salt added. The culprit does seem to be the sodium. Thanks for posting the article. I'll have to finish it later.   

[Stu]

Interesting article. I notice that altho his fluid intake will be about the same, my husband's BP and weight goes slightly up whenever he eats pre-packaged lunch meats compared to fresh cooked beef with no salt added. The culprit does seem to be the sodium. Thanks for posting the article. I'll have to finish it later.

This is interesting. The paper talks a lot about the sodium added in dialysis to reduce the chance of cramping and BP crashes causing the patient to be thirsty; thus the never ending cycle of thirst, big fluid gains, needing to add sodium during dx to mitigate bp crashes and cramp when all that fluid is being ripped off.

It's interesting that the author of the paper thinks it's unreasonable to ask dx patients to reduce fluid intake while they're filling them up with sodium during the treatment that's meant to be helping them.

[PrimeTimer]

This article (from Stu) got me reading up more on sodium and why it is used in dialysate. Now, I won't pretend to fully understand all the medical speak because most of it is way over my head but I think we all understand that sodium causes some to swell up and in turn, blood pressure to rise. But holy banana split! When you read about sodium in dialysate and then think about patients being told to restrict their fluid intake and suffering BP crashes and cramping during dialysis well..like I said, holy banana split!

Here's another article about sodium in dialysate. It's old, from 2000 written by Michael J Flanigan. It can be found on "Kidney International" and the article was titled "Role Of Sodium In Hemodialysis".
I found Paragraph 5 that starts with "By 1980 "hypotonic dialysate was no longer crucial..." to be very interesting if not, a real eye opener. Hope the link works.

http://www.nature.com/ki/journal/v58/n76s/full/4491958a.html

[Bill Peckham]

The author is saying that low fluid gains (in someone with no output) signals poor nutrition, and it is the poor nutrition that leads to mortality. I have a different theory for why low fluid gains are associated with higher mortality (and there is also data showing low dialysate sodium correlates to worse mortality).

The way I think of it is that the body wants its sodium level where it wants its sodium level. To the body keeping the sodium level of the body's fluid in range is the number one goal, and is one of the main jobs of healthy kidneys. If the sodium level increases you are driven, compelled, to drink fluid and thereby dilute the sodium level to what the body wants, which is what the author points out. But what happens if the sodium level gets too low?

With healthy kidneys the body will produce urine and thus concentrate the sodium getting its sodium level back to where it wants it, but what can the body do if the kidney's don't work? There is no mechanism available. There must be a consequence of too low sodium on the workings of the body, I'd say the surprising result from low fluid gains and from the use of low sodium dialysate suggests the consequences are considerable.

[Charlie B53]

When our foods come in cans and boxes, we probably should NOT eat it as it is most often highly loaded with salt.

Fresh and frozen are far healthier choices.

Fortunately for me being on PD with some residual urine output I am not fluid restricted, yet.  I do see very few days of total weight lose from morning to night but there are a few of those days.  Most often I see anywhere from a half pound to slightly over three pounds gain, most all removed by that nights PD treatment.

Am I 'normal' as far as PD patients go?    I have no idea, I know no other patients other than what I read here at IHD.

[PrimeTimer]

I don't like it when my husband buys himself prepackaged lunchmeat because the sodium seems to make him retain water and in turn, make his blood pressure rise. Fortunately he doesn't do that very often, like once in a blue moon. That's good because that means I don't have to get on him about it, which I hate doing because he goes thru so much as it is.   

Don't know if "where in the body" a person/dialysis patient retains the most fluid has any impact on their sodium level and what their level should be but, my husband's Neph says he seems to retain all of his in his belly area (opposed to the legs or ankles). Hhmm..something else interesting about this business of sodium...my mother taught me to eat saltines or what is sometimes called "soda crackers" to help with nausea, along with drinking a little 7-UP or Sprite to settle things down. Especially when you've got the stomach bug. Always worked. But for a kidney patient that's probably the last thing they should have.

[Charlie B53]

The saltines have a dual effect.  The starch swells, absorbing stomach acids while the salt leads to body to retain water.  The body has usually lost water thru vomiting. diarrhea, or both and can quickly become in danger of dehydration.

The Sprite or 7-Up adds water and the sugar does coat and calm stomach lining.

Ritz crackers are a lower salt alternative.  A bagel can also be used.

But you have to be very aware of the patients water content.  Onset of dehydration can be very rapid with little prior warning.

[PrimeTimer]

I remember my doc telling me that if my lips feel dry and cracked then it's too late, I am already dehydrated. At that point, I load up on water and it takes hours before I feel decent. I imagine people on dialysis who are already dehydrated that have too much fluid robbed/removed from them and too quickly at their treatments end up with BP crashes and then left with feeling wiped out for the rest of the day. Being dehydrated makes you feel lousy and takes a good while to recover from, whether you have kidney disease or not!