Rationale for withholding calcium gluconate in DKA hyperkalemia

[Jabbed]

I never really understood this and none of the protocols ever seem to mention why calcium gluconate shouldn't be administered in the setting of DKA hyperkalemia. I understand that insulin therapy eventually corrects the existing potassium shift, but why isn't calcium used as a cardio-protective adjunct?

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[Psai]

probably because your serum potassium and cellular potassium are completely different

 

[Jabbed]

probably because your serum potassium and cellular potassium are completely different

In the right scenario, ECG changes suggest that elevated serum potassium in DKA (despite decreased intracellular potassium) produces electrophysiological effects c/w hyperkalemia.

 

[Jabbed]

probably because your serum potassium and cellular potassium are completely different

You would also logically expect a high serum potassium/low intracellular potassium (high/low compared to the normal physiologic concentrations) to produce a depolarized resting membrane potential.

 

[Cytarabine]

I wasn't aware of this. Where are you reading not to give it? I can't think of a reason you wouldn't give it if it was indicated, eg ekg changes with hyperK

 

[DermViser]

I wasn't aware of this. Where are you reading not to give it? I can't think of a reason you wouldn't give it if it was indicated, eg ekg changes with hyperK

That's what I was wondering too.

 

[Jabbed]

I wasn't aware of this. Where are you reading not to give it? I can't think of a reason you wouldn't give it if it was indicated, eg ekg changes with hyperK

Well I've never explicitly read that you're not meant to dose it, but calcium gluconate never appears in any of the treatment protocols for management of serum potassium in DKA. I've seen this scenario maybe 2 or 3 times (DKA with high serum K and T wave changes) where the attending never gave Ca and just started replacing potassium after bringing [K] down to ~5mEq. n=3, but no bad outcomes.

 

[DermViser]

Well I've never explicitly read that you're not meant to dose it, but calcium gluconate never appears in any of the treatment protocols for management of serum potassium in DKA. I've seen this scenario maybe 2 or 3 times (DKA with high serum K and T wave changes) where the attending never gave Ca and just started replacing potassium after bringing [K] down to ~5mEq. n=3, but no bad outcomes.

Calcium gluconate doesn't manage serum potassium. It's more for cardioprotective effect as it stabilizes the cardiac membrane.

 

[Jabbed]

Calcium gluconate doesn't manage serum potassium. It's more for cardioprotective effect as it stabilizes the cardiac membrane.

Ya but it normally crops up in any discussion on the management of hyperkalemia. You know.. 1. Ca 2. Insulin 3. IV fluids..

 

[Jabbed]

As explained to me when I asked on those occasions: "we are treating the hyperkalemia with insulin therapy so there's no need for Ca." Then they would say something similar to psai's comment concerning potassium depletion and the transcellular gradient. Idk, it just never made much sense to me.

 

[DermViser]

Ya but it normally crops up in any discussion on the management of hyperkalemia. You know.. 1. Ca 2. Insulin 3. IV fluids..

What I mean is it doesn't directly decrease the serum levels of potassium. Insulin - yes. Beta blockers - yes. Kayexylate - yes.

 

[CherryRedDracul]

I'd only use calcium if I started to see EKG changes consistent with severe hyperkalemia (loss of P waves, widening QRS, peaked T waves, etc.). Otherwise, the other strategies of management without calcium should be enough.

The risk of giving IV calcium to prophylactically prevent arrythmias is, ironically, arrythmias, so it shouldn't be used unless the benefits outweigh the risks.

 

[Raryn]

Ya but it normally crops up in any discussion on the management of hyperkalemia. You know.. 1. Ca 2. Insulin 3. IV fluids..

It normally crops up in any discussion on the management of hyperkalemia... if there are EKG changes. It's not 1. Ca 2. Insulin 3. IV fluids. It's look at the patient, get an EKG and 1. Ca iff there are EKG changes 2. Insulin+D50, Albuterol (at a high dose), and/or Bicarb (iff the patient is also acidotic) 3. Kayexalate, fluids+diuretics, or dialysis (depending on how high the level is and the status of the patient).

With DKA, the above management changes a little. You can still give Ca if there are EKG changes, and you'll be giving high dose insulin (plus sugar if necessary) to get the serum level down, but you know that the total body potassium is actually quite low, so you would never give diuretics or kayexalate. Dialysis may be an option for management of DKA only in a patient who already has ESRD and is otherwise quite unstable, but even then the point is not to remove K.

 

[Druggernaut]

Ya but it normally crops up in any discussion on the management of hyperkalemia. You know.. 1. Ca 2. Insulin 3. IV fluids..

I've never heard that you wouldn't give it to someone in DKA. However, you're not supposed to give calcium gluconate unless the QRS begins to widen, or a few other situations that have less uniform acceptance.

What I mean is it doesn't directly decrease the serum levels of potassium. Insulin - yes. Beta blockers - yes. Kayexylate - yes.

Insulin's good. You can also throw in some albuterol along with your fluids and calcium if needed. And dialysis for renal failure or patients that are otherwise not responding to treatment.

Beta blockers will worsen hyperkalemia, and there's no evidence to support the use of Kayexalate, though that won't stop many from using it.

http://www.acep.org/Education/Continuing-Medical-Education-(CME)/Focus-On/Focus-On----Critical-Decisions--Hyperkalemia/
http://emcrit.org/misc/is-kayexalate-useless/

 

[Morzh]

It normally crops up in any discussion on the management of hyperkalemia... if there are EKG changes. It's not 1. Ca 2. Insulin 3. IV fluids. It's look at the patient, get an EKG and 1. Ca iff there are EKG changes 2. Insulin+D50, Albuterol (at a high dose), and/or Bicarb (iff the patient is also acidotic) 3. Kayexalate, fluids+diuretics, or dialysis (depending on how high the level is and the status of the patient).

With DKA, the above management changes a little. You can still give Ca if there are EKG changes, and you'll be giving high dose insulin (plus sugar if necessary) to get the serum level down, but you know that the total body potassium is actually quite low, so you would never give diuretics or kayexalate. Dialysis may be an option for management of DKA only in a patient who already has ESRD and is otherwise quite unstable, but even then the point is not to remove K.

OP: Coincidentally I asked my seasoned ED professor this exact question today during our not-so-busy shift. This is basically the answer. She said hypothetically calcium gluconate could be used but she's never had to use it in DKA because (a) it's rare for DKA-induced hyperkalemia to get to the point of significant ECG changes and (b) insulin/glucose/fluids always fixes it before it gets to that point.

 

[link2swim06]

I've never heard that you wouldn't give it to someone in DKA. However, you're not supposed to give calcium gluconate unless the QRS begins to widen, or a few other situations that have less uniform acceptance.



Insulin's good. You can also throw in some albuterol along with your fluids and calcium if needed. And dialysis for renal failure or patients that are otherwise not responding to treatment.

Beta blockers will worsen hyperkalemia, and there's no evidence to support the use of Kayexalate, though that won't stop many from using it.

http://www.acep.org/Education/Continuing-Medical-Education-(CME)/Focus-On/Focus-On----Critical-Decisions--Hyperkalemia/
http://emcrit.org/misc/is-kayexalate-useless/

Bingo! The experts on electrolytes don't recommend calcium until the QRS increases. Some physicians will give calcium for peaked T waves but there isn't any evidence in really supporting that practice.

Additionally remember that DKA patients are generally overall depleted in potassium and as soon as you fix the acidosis this will become apparent.

 

[Jabbed]

Great responses, thank you!

 

[Cytarabine]

I've never heard that you wouldn't give it to someone in DKA. However, you're not supposed to give calcium gluconate unless the QRS begins to widen, or a few other situations that have less uniform acceptance.



Insulin's good. You can also throw in some albuterol along with your fluids and calcium if needed. And dialysis for renal failure or patients that are otherwise not responding to treatment.

Beta blockers will worsen hyperkalemia, and there's no evidence to support the use of Kayexalate, though that won't stop many from using it.

http://www.acep.org/Education/Continuing-Medical-Education-(CME)/Focus-On/Focus-On----Critical-Decisions--Hyperkalemia/
http://emcrit.org/misc/is-kayexalate-useless/

But there may be some hope for newer resins not too long down the road

http://www.nejm.org/doi/full/10.1056/NEJMe1414112

 

[TooMuchResearch]

I've never heard that you wouldn't give it to someone in DKA. However, you're not supposed to give calcium gluconate unless the QRS begins to widen, or a few other situations that have less uniform acceptance.



Insulin's good. You can also throw in some albuterol along with your fluids and calcium if needed. And dialysis for renal failure or patients that are otherwise not responding to treatment.

Beta blockers will worsen hyperkalemia, and there's no evidence to support the use of Kayexalate, though that won't stop many from using it.

http://www.acep.org/Education/Continuing-Medical-Education-(CME)/Focus-On/Focus-On----Critical-Decisions--Hyperkalemia/
http://emcrit.org/misc/is-kayexalate-useless/

Yeah, I definitely don't do the Kayexalate, and I think most of our hospitalists have stopped asking why we didn't give it. (They might still do it once they get upstairs, though.)

 

[TooMuchResearch]

But there may be some hope for newer resins not too long down the road

http://www.nejm.org/doi/full/10.1056/NEJMe1414112

Maybe...

http://www.emlitofnote.com/2014/11/a-brave-new-kexylate-free-world.html?m=1

 

[DermViser]

I've never heard that you wouldn't give it to someone in DKA. However, you're not supposed to give calcium gluconate unless the QRS begins to widen, or a few other situations that have less uniform acceptance.



Insulin's good. You can also throw in some albuterol along with your fluids and calcium if needed. And dialysis for renal failure or patients that are otherwise not responding to treatment.

Beta blockers will worsen hyperkalemia, and there's no evidence to support the use of Kayexalate, though that won't stop many from using it.

http://www.acep.org/Education/Continuing-Medical-Education-(CME)/Focus-On/Focus-On----Critical-Decisions--Hyperkalemia/
http://emcrit.org/misc/is-kayexalate-useless/

Sorry not B-blockers, I mean Beta-agonists (hence correct, albuterol). LOL!!