Dialysis pump speed question

[del]

My husband has a pump speed of 250 on nocturnal. In center he was having a pump speed of about 450.  I'm so glad that we are able to do the 5 nights aweek. Makes a big difference to the way you feel!!

[napala turki]

hello there, it has been 120 days I'm off this site, busy with new position and new tasked.

Back to the topic, i"m now running at 450 ml/min with 15G at 52 yrs old, previously was 300, 350, 400, and now 450, after confirmed by cardiologist my heart is normal.

I was told, that higher pump speed will act as a heart scanner, if there is a chest pain during the dialysis, indication of heart problem. Asked the cardiologist too about the heart blood flow rate, it was approx 4L/min, so there should be no problem.

[napala turki]

hello there, it has been 120 days I'm off this site, busy with new position and new tasked.

Back to the topic, i"m now running at 450 ml/min with 15G at 52 yrs old, previously was 300, 350, 400, and now 450, after confirmed by cardiologist my heart is normal.

I was told, that higher pump speed will act as a heart scanner, if there is a chest pain during the dialysis, indication of heart problem. Asked the cardiologist too about the heart blood flow rate, it was approx 4L/min, so there should be no problem.

Now I'm having a new machine, which able to monitored total blood flow during dialysis, so 4 hours it took >100 litres of blood circulation thru the pump, dialyser and back to the body... I was told, the cleareance is much bigger.

[mogee]

Dialysis cleans the fluid in the body. A person with 4.7 litters of blood would have over 30 liters of fluid. As a general rule for every liter of blood you have two liters of fluid between your cells and 4 liters in the cells.

Just quickly cleaning the blood - using a super efficient artificial kidney and a 600 blood pump speed - does not get you to where you want to be. You've only cleaned one seventh of the fluid in the body. You need time for the fluid and waste to transport between the compartments.

There is no substitute for time. The majority of the fluid is in the cells - four sevenths of the fluid you need to cleanse. But you only have access to the blood which is two semipermeable membranes away from the cell's liquidy cytoplasm.  The dynamics of the body's three fluid chambers are a bitch.

This is precisely why pump speeds above 300ml/min are unnecessary when using nocturnal dialysis, and higher speeds are only marginally better for 3.5 or 4.0 hour sessions.  I was told that it takes four hours of dialysis for medium weight molecules in the interstitial spaces to begin crossing into the bloodstream.  These waste products cannot  be removed at all by conventional dialysis regardless of how rapidly blood is pumped through the machine.  Thanks Bill, for your lucid description of the three fluid compartments.

[Bill Peckham]

Dialysis cleans the fluid[/font] in the body. A person with 4.7 litters of blood would have over 30 liters of fluid. As a general rule for every liter of blood you have two liters of fluid between your cells and 4 liters in the cells.

Just quickly cleaning the blood - using a super efficient artificial kidney and a 600 blood pump speed - does not get you to where you want to be. You've only cleaned one seventh of the fluid in the body. You need time for the fluid and waste to transport between the compartments.

There is no substitute for time. The majority of the fluid is in the cells - four sevenths of the fluid you need to cleanse. But you only have access to the blood which is two semipermeable membranes away from the cell's liquidy cytoplasm.  The dynamics of the body's three fluid chambers are a bitch.

This is precisely why pump speeds above 300ml/min are unnecessary when using nocturnal dialysis, and higher speeds are only marginally better for 3.5 or 4.0 hour sessions.  I was told that it takes four hours of dialysis for medium weight molecules in the interstitial spaces to begin crossing into the bloodstream.  These waste products cannot  be removed at all by conventional dialysis regardless of how rapidly blood is pumped through the machine.  Thanks Bill, for your lucid description of the three fluid compartments.

I haven't reread this thread in long time - thanks Mogee. This issue about time and the three fluid compartments is poorly understood but it is at the heart of a lot of problems people experience using dialysis.

[Trikkechickk]

About the 3 compartments of fluid retention - I have no colon because of Crohn's disease, and therefore don't reabsorb water from the GI tract.  When I was in-center, often times I would be over my dry weight but still cramping in legs and neck.  Hard to convince the tech's it was going on.  Now that I do home hemo, not a problem.

[Bruno]

No Richard, you are quite right...like you I'm an Aussie and my pump speed is 300. What the posts are missing is not so much the blood turnover, which may or may not be useful in removing toxins but the removal of fluid. If you want to get that off safely and easily you need time, not blood speed.
Some threads also say that time is what you need to do a good job on toxins, not pump speed.
There is certainly a tendency to confuse pump speeds with shorter sessions as though the faster the pump speed the shorter the session can be.
With 15 hours per week you are going nowhere.