In our outpatient unit we do very well with hgb,albumin,calc/phos,kt/v etc.But our Bicarb levels are atrocious!Only 7% of pt with Bicarb >22!I have reviewed our lab drawing technique, and our specimen handling without identifying a cause.Our Bicarbs are set at 37 as Rx. by our MD's.The only issue I keep coming back to is that we(and this is a long story) only have F-70 NR dialyzers despite better membrane technology that is available.Any thoughts or suggestions would be appreciated.

I was on a F70NR and saw my CO2 take a nosedive. My doctor said most patients have diminishing CO2s as their kidney function goes down. I was put on sodium bicarb to correct this problem.

Two months ago, I was switched to an ASAHI AMBIO HX75. My CO2 shot up to 32 when it had previously been just passing in the low 20's (this is with taking 3 sodium bicarb a day in both instances).

I had a good clearance with the F70NR averaging about 1.8. It sank down to 1.37.

I've now been taken off this dialyzer and have been out on ASAHI's 100 model. Will see how it affects my CO2 next month.

What Bicar Series are you using? And are u checking your bicarb mixing phonex meter?

To Tech-We use Naturalyte 9000 series and we calibrate our Phoenix Meter Q day.
To Patient-Do I understand you correctly that on the F70 NR your adequacies were better but bicarbs were worse?For some reason our physicians do not like to put pt.s on oral bicarb.And they worry about raising bicarbs in the machines greater than 37 because of possible arrhythmias with low potassium pt.s and because of the risk of bacterial growth.
It is a mystery to me!It seems to me that with great adequacies like we have,pt.s would be less acidotic.Thank you for your attention to my problem.I like to only offer the best to our pt.population!

The bicarb level set on the machine may not be the actual level being delivered to the patient. This was a problem with the some delivery systems for a time. You may want to verify actual bicarb levels in your final dialysate by lab analysis.

Kind regards

Are your patients taking renagel. I got our unit to change to Naturlyte 9000 which can deliver a 39-40 once the machines are recalibrated and the acid mix changed. Renagel dropped my co2 to 11. Now after three months of the 9000 it's up to 27. bicarb tablets are definitely not the answer when you consider the added salts and BP.

Dare to HD,
Yes, you did understand me correctly that on the FR70NR my adequacies were better, but my bicarbs were worse.

Can you find out the reason your physicians don't like to put patients on oral bicarb? I would be very interested to know as that's 3 more pills a day I must remember to take and they are very unpleasant ( full of sodium) if not swallowed exactly right.

What make/model machines do you use? I'm sure you do not use external meters, and without an external meter, your rate for bicarb may not be accurate.

Can you provide an article that shows there is bacterial growth with a bicarb setting of greater than 37 or is this just your doctors' opinion? I have always been run at 38.

What is the better membrane technology then the F70NR?

Dear Patient,
I will have to ask our physicians why (other than the sodium) they do not use oral bicarb.
We use 2008H machines with not the latest software,don't know the #. There is no article that I have seen about bicarb and bacterial growth, but as a dialysis professional for a long time, it is general knowledge that the acid component of dialysate is much less of a growth medium than the bicarb portion.Thus we keep bicarb for less time and spend more time disinfecting jugs etc. where bicarb is involved.
The F70 NR is a great dialyzer,which we were all thrilled to see come along.But now, the Optiflux is availabe and has better clearances etc.And soon there will be a step beyond the Optiflux technology.It sure is great to encounter patients who are conversant with this sort of thing!Wanna transfer to our clinic? Just kidding. I will post what the MD's have to say about bicarb when I find out.

It really sounds like you have a mixing problem.When making 9000 series your level should be 70-74ms. And when mixing your water levels should be with a total combine bicarb and water 95liters 1 bag and 190 litters with 2 bags. Read step 3 on your bicarb label. You can stretch it to 100 liters but you start to have low serum bicarb levels. Humor me and try it. I had several clinics with this problem. It takes 2 months before you really see a difference. Also I had the MD raise my bic to 38 in only 1 clinic. And the nurse r to report any one who reaches >27 to MD.

I was surprsed that noone responded to the Renagel causation. Any patient who takes a lot of Renagel will see a resultant drop in CO2 and a rise in Potassium.
This is due partly to the loss of buffer contained in Phoslo. but also due to the HCL (hydrochloric acid) content of Renagel. Also, Renagel drops the Ph in the GI, and loses its binding capacity as the Ph drops. So patients take more, and become acidotic. Raising the machine bicarb to 39 (Naturlyte 9000) can help, but I find that 1 teaspoon of bicarb of soda,in water, twice a week will maintain my CO2 around 27 -30.

A RN said that they found that CO2s were low due to time/distance to their lab across the country. When tested locally, were in range.

Can anyone tell me if there is a problem with mixing bicarb jugs with a power mixer where the end attachment is made out of metal (Stainless steel, aluminum or any metal in general)Thank you.

are talking about the blade which mixes the bicarb? if so, Stainless Steel is usely what you will see on stand alone mixer systems, It is Ok, just dont use brass.lol.

Do you use batch-mixed, or individually-mixed bicarb? Some bicarb systems cause more than adequate agitation of the solution leading to gassing-off of CO2 and thus a lower CO2 in the dialysate. I've seen some people turn on the mixer and let it run for longer than necessary because they're out setting up machines or whatever. Add to this the fact that some dialysis machines de-gas dialysate in the machine after the bicarb has been added.

Also, I've wondered before how a high negative pressure on the pre-pump arterial side of the extracorporeal circuit affects blood gases. I know that this, to some degree, causes hemolysis.

Larry,

In reference to bicarb mixing times, we have mixers from FMC and have replaced the on/off switch with a 15 minute timer switch - problem solved.

As far as degassing blood gases go, from doing my own flow studies of Blood Pump Speed vs Actual Delivered Flow (using plain tap water) I could visually see degassing at pre-pump pressures once they went lower than -150. I wasn't testing for this, it was just an observation and the MD's did not seem concerned.

Chuck