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Post by Falcon on Oct 9, 2021 7:35:13 GMT
If we are using an acid concentrate having a label showing following conc in mmol/l;
Na- 138
K- 2
Ca-1.5
Mg-0.5
Cl-109
Acetate-3
Hco3-32
Dextrose-100
Bicarb used is 8.4% without NaCl.
In an ideal conditions what should be Na+ and Bic conductivity on machine to get the above mentioned electrolyte concentration in final dialysate?
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Post by Chuck Weddle on Oct 9, 2021 10:21:13 GMT
Falcon,
There is no direct conversion for mmol/L to mEq/L then conductivity. Contact B. Braun, you can tell them the concentrate manufacturer and formula and they can calculate the approximate conversion.
You should also contact your father's nephrologist for the machine settings as they are prescription items. If your father's prescription is for mmol/L, ask his nephrologist to have your biomed tech to configure the machine for mmol instead of conductivity. The Dialog+ is capable of this.
Also a word of warning: Any information posted or answers given to questions are only opinions/suggestions of the individual based on limited information and may or may not be correct in any particular circumstance. You should always verify things with your father's medical team.
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Post by Falcon on Oct 9, 2021 22:16:30 GMT
Falcon, There is no direct conversion for mmol/L to mEq/L then conductivity. Contact B. Braun, you can tell them the concentrate manufacturer and formula and they can calculate the approximate conversion. You should also contact your father's nephrologist for the machine settings as they are prescription items. If your father's prescription is for mmol/L, ask his nephrologist to have your biomed tech to configure the machine for mmol instead of conductivity. The Dialog+ is capable of this. Also a word of warning: Any information posted or answers given to questions are only opinions/suggestions of the individual based on limited information and may or may not be correct in any particular circumstance. You should always verify things with your father's medical team. I'm already much cautious about the things you have warn/ adviced about and nothing will be changed without consultation of the nephrologist and prior lab test conformation of dialysate,but the issue here is non avalbilty of good quality concentrates,lack of alternatives provided by bbraun and to add to this bbraun tech guys here lacking in knowledge. As for my above question even though we change from conductivity to mmol/l on machine machine is actually going to measure the conductivity.Purpose for asking was to know what levels of Na and bicarb you generally keep on machine(for above mentioned label of acid concentrate, which is I think is a much often used concentration) so that a test sample of dialysate can be drawn for that particular setting and send for lab testing. Also when it comes to the working of internation brand (even the reputed ones)here, their service quality degrades, and its not like what you are getting in your country. Hope you'll be able to understand. |
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Post by Falcon on Oct 10, 2021 3:27:18 GMT
If we are using an acid concentrate having a label showing following conc in mmol/l; Na- 138 K- 2 Ca-1.5 Mg-0.5 Cl-109 Acetate-3 Hco3-32 Dextrose-100 Bicarb used is 8.4% without NaCl. In an ideal conditions what should be Na+ and Bic conductivity on machine to get the above mentioned electrolyte concentration in final dialysate?  |
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Post by Chuck Weddle on Oct 10, 2021 9:53:19 GMT
Here in the US, most use mEq/L though some do use mmol/L.
My companies standard bath is:
Na 137 mEq/L
K 2.0 mEq/L
Ca 2.5 mEq/L
Mg 1.0 mEq/L
Cl 105.5 mEq/L
Acetate 4.0 mEq/L
Dextrose 100 mg%
HCO3 33 mEq/L
What this levels are in mmol/L I have no idea.
To obtain these levels, our machines are set for Bicarb 3.1 mS/cm and Final Conductivity of 13.6 mS/cm.
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Post by Falcon on Oct 11, 2021 10:42:09 GMT
Here in the US, most use mEq/L though some do use mmol/L. My companies standard bath is: Na 137 mEq/L K 2.0 mEq/L Ca 2.5 mEq/L Mg 1.0 mEq/L Cl 105.5 mEq/L Acetate 4.0 mEq/L Dextrose 100 mg% HCO3 33 mEq/L What this levels are in mmol/L I have no idea. To obtain these levels, our machines are set for Bicarb 3.1 mS/cm and Final Conductivity of 13.6 mS/cm. Thank you Chuck. |
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Post by Falcon on Dec 10, 2021 12:23:37 GMT
Here in the US, most use mEq/L though some do use mmol/L. My companies standard bath is: Na 137 mEq/L K 2.0 mEq/L Ca 2.5 mEq/L Mg 1.0 mEq/L Cl 105.5 mEq/L Acetate 4.0 mEq/L Dextrose 100 mg% HCO3 33 mEq/L What this levels are in mmol/L I have no idea. To obtain these levels, our machines are set for Bicarb 3.1 mS/cm and Final Conductivity of 13.6 mS/cm. The conductivity calculation for Bicarb is conductance factor×charge(mEq/L)÷1000 Which is 73.464×33÷1000=2.424mS/cm. My question is then why Bicarb conductivity is kept at |
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Post by Falcon on Dec 10, 2021 12:25:05 GMT
The conductivity calculation for Bicarb is conductance factor×charge(mEq/L)÷1000
Which is 73.464×33÷1000=2.424mS/cm.
My question is then why Bicarb conductivity is kept at 3.1 intead of 2.4
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Post by Chuck Weddle on Dec 10, 2021 13:00:57 GMT
The conductivity calculation for Bicarb is conductance factor×charge(mEq/L)÷1000 Which is 73.464×33÷1000=2.424mS/cm. My question is then why Bicarb conductivity is kept at 3.1 intead of 2.4 Falcon, I don't know where you got your formula from but it is nothing I have ever seen used in dialysis. IF your formula is even close to being correct, I suspect that it isn't accurate because of the chemical reaction that takes place when the acid concentrate is mixed with the bicarbonate concentrate from the cartridge. The only formula I have ever seen used for THEORETICAL conductivity is (Na + K + Ca + Mg) – 6 / 10. Also, the bicarbonate (HCO3) does not play into the conductance of the solution, only its sodium contribution. |
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Post by Deleted on Dec 10, 2021 16:41:32 GMT
Pls take a look at this(attach.) Attachments:
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Post by Chuck Weddle on Dec 10, 2021 18:09:51 GMT
Pls take a look at this(attach.) Again, I have never seen anything like that formula and quite frankly, the "conductance factor" looks like it is something made up in order to get close to what they think the answer should be. Bicarb (HCO3) and Acetate (C2H3O2) do not have a charge to contribute to the conductivity. It's the Na that's associated with them that does this. Why is the "conductance factor" for the two Na's different? If you follow the formula I posted, you'll see that it comes very close. I can tell you that on OUR machines, with OUR purified water, OUR acid concentrate, and OUR Solcart cartridges, the numbers I posted are lab verified. If any of those things are changed, results may be different. When a machine is first commissioned for use, lab samples are done, adjustments made if needed, followed by more lab samples....until the proper settings are found. |
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Post by SrCusEngr on Dec 10, 2021 19:40:08 GMT
When dealing with mEq/L, you must work with the VALENCE electrons (Ionic charges) present in the solution. It is not a straight correlation, as has often been mentioned. Once the salts have been dissolved into the acetic acid, they become ions with a charge. Those ions are what performs the ability to conduct an electrical current.
Sodium is Na+; Potassium is K+; Calcium is Ca++; Magnesium is Mg++. These are all cations.
Bicarbonate is an anion, HCO3-. So is Chlorine (Cl-), so NaHCO3 has no charge because one sodium atom is bound to one bicarbonate molecule.
"mEq" is a unit of measurement that is referred to as one-thousandth of an equivalent of a chemical. MEq is used to measure substances with electrolytes. ... “Mmol,” on the other hand, is a unit of measurement that is referred to as one-thousandth of a gram molecule. A measurement of weight. So there is no direct correlation.
If the doctor orders a bath of 2K 2.5Ca, it is because that is the type of electrolytes he wants the patient to have. And if he orders a final conductivity of 13.8 mS/cm, or possibly 140 mmols/L it is because that is how much sodium he wants the patient to receive. And this is all determined by the patient's blood work. Too much sodium, and the patient will start to get thirsty and drink water, defeating fluid removal. The electrolytes will always be in balance in the bath. The machine cannot discriminate between a K ion and a Mg ion.
There is a lot of science and chemistry behind all this. Which means a lot of formulas. Too much so for this forum. And, while there is a lot of stuff on the internet, if you want to learn about mmols, mEqs and conductivity, go to reputable sources and learn for yourself how to calculate them. May I recommend starting with: |
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Post by Deleted on Dec 10, 2021 19:58:55 GMT
I have the above info from this source(attach.) So dear SrCusEngr is it correct or not? Attachments:
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Post by Chuck Weddle on Dec 10, 2021 20:34:17 GMT
I have known John Sweeny for quite a few years and he is one of the most intelligent people I have ever met. He also has a unique ability to explain difficult topics in a way that anyone can understand. The key word in that statement is the word EXPLAIN. You are drawing conclusions from a slide from a very complicated and detailed presentation. Slide from a presentation are essentially just an outline of major points, you have to hear the presentation to put those points in to context.
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