Hello! Just wondering what everyones conductivity runs on final dialysate using 4000 series bicarb/acid. Ours is running around 14.4-14.6 mS. Our bicarb after mixing it in the mix tank is 50 + or - 2 mS.

Sa I used the 4000 series and my final conductivity bicarb is 52 mS which is perfect because if you measure the conductivity in a pre mixed bicarb jug coming from factory, you will find out the same conductivity reading. I think that will be the best reference point.

Machine conductivity readings vary due to the different Na+ and bicarb settings per patient. 14.6 mS seems a little high, but again, it depends on the individual patient requirements.

botech is right. what is your acid and bic set at? That will make a difference, as will the conductivity of pre mixed bicarb as quilla pointed out.

I understand, but all my pumps couldn't be off. I checked all flows/pumps/meters.

Base Na+ 140
Bicarb 35

Could be NaCl modeling and/or 3-4K concentrates being utilized. Currently, we are utilizing 4K series and std bath is 2K, condos at 14 to 14.2mS.

How old are your machines?

New installs are notorious for being WAY out of calibration.

I just had two new K machines installed in January. The Fresenius tech actually wrote down on the installation form 13.3 and 13.4 as the cond. of the new machines. I calibrated the acid and bicarb pump volumes, and the cells, and cond. was then 13.9/14.0. This was with 4000 series conc.

We are using 2419 Granuflo and 4112 bicarb powder. The sodium is 100 mEq/ml in the Granuflo and 37 mEq/ml for the bicarb. This suggests to me that my base sodium setting should be 137 mEq/ml and the base bicarb setting should be 37 mEq/ml. The TCD using these 2 values is 13.3mS/ml. This seems too low. Also, the electrolytes are less then the nominal amount and can be observed on the dialysate "page" as 2.4mEq/ml as opposed 2.5mEq/ml for K for example. What is wrong with this picture? Why isnt the TCD in a more "normal" range, such as 13.6- 13.8, and why are the individual electrolytes lower then the values in the granuflo? I calculated the TCD using Na+K+Ca+Mg-6/10, 137+2.5+2.0+.8-6/10=136.3. Should my base sodium be 140, even though my granuflo and bicarb together equal 137mEq/ml?

if you have central feed for acid and bic check your pressure comming from the wall.if it is too high adjust the pressure or replace the pressure regulator.i have had this happen alot and you just need to make the adjustment.

What is NaCl modeling? We are using only 2k and 3k 2.5...

Our average PSI out of "central feed" both Bicarb and Acid are 4.5 psi.

The machines have roughly 1k hrs.

I recalibrated a machine yesterday: Pumps, Conductivity, Temp - Still the same "high".

Thank you for your help. Please continue to give me ideas!

Bad acid/bicarb pump calibration-just replaced 4 acid pumps to get rid of the same problem. The pumps were pulling less than the 16.2ml(15.0ml), 23.4ml(22.0ml) when you cal-ed them,but if you just checked them like the pm book says they were good.

Pumps,

I don't think the pumps are off. I have a policy that the calibration must be on the money. I didn't even have to adjust any of the numbers to match what the flask showed. Switching to 4000 has been a nightmare.

Our TCD is 13.7 by the way. Our CPOS is 14.4-14.6. This is not a TMP/Hansen issue, I ruled out nurses.

Any updates on this guys?

have you checked your balancing chamber volume to see if it's in range? a slight tear will cause nightmares on cond.