Bean Team consult

[GoBuckeyes913]

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Question: Can you create a devastating mismatch between calcium and phosphorus by giving 2-3 doses of 1 gram calcium glauconate when treating significant hyperkalemia in an emergent setting?

Scenario: 58 yo female with acute renal failure from hypovolemia/dehydration. BUN 110, Cr 9.25, Ca 7.1, Na 133, K+ 8.0. Anion Gap 21. Vitals stable aside from bradycardia at 40. ECG shows sinus brady, widened QRS. 1st dose CaGlu given, QRS narrows and HR improves to 60. Usual hyperK+ treatment started. ICU consulted. 1.5 hrs later, Brady again and same as before, another CalGlu given, Brady and QRS improve. ANOTHER 1.5 hrs later, same situation and given 3rd dose of CaGlu (final dose) and improves. This was all done over a course of 7 -8 hrs.

ICU doc gives passive aggressive comment about 3 doses of calcium to me (ED doc). I felt fatal arrhythmia trumped a possible mismatch, but wouldn't think 3-6 grams of Calcium glauconate would be enough to tip the boat in that time period. Thoughts? Constructive criticism? Only trying to better my practice, especially if I should be doing something else in the ED. Any feedback from nephro colleagues would be appreciated.

 

[gutonc]

The only advice I would give is to let passive-aggressive bulls*** roll off your back. We've all been on both sides of that discussion and it's a losing battle.

Maybe you could create that devastating mismatch between Ca and Phos. But you could have also created a devastating mismatch between being alive and not, which, as you point out, is what you were trying to avoid.

 

[CptNemo]

Question: Can you create a devastating mismatch between calcium and phosphorus by giving 2-3 doses of 1 gram calcium glauconate when treating significant hyperkalemia in an emergent setting?

Scenario: 58 yo female with acute renal failure from hypovolemia/dehydration. BUN 110, Cr 9.25, Ca 7.1, Na 133, K+ 8.0. Anion Gap 21. Vitals stable aside from bradycardia at 40. ECG shows sinus brady, widened QRS. 1st dose CaGlu given, QRS narrows and HR improves to 60. Usual hyperK+ treatment started. ICU consulted. 1.5 hrs later, Brady again and same as before, another CalGlu given, Brady and QRS improve. ANOTHER 1.5 hrs later, same situation and given 3rd dose of CaGlu (final dose) and improves. This was all done over a course of 7 -8 hrs.

ICU doc gives passive aggressive comment about 3 doses of calcium to me (ED doc). I felt fatal arrhythmia trumped a possible mismatch, but wouldn't think 3-6 grams of Calcium glauconate would be enough to tip the boat in that time period. Thoughts? Constructive criticism? Only trying to better my practice, especially if I should be doing something else in the ED. Any feedback from nephro colleagues would be appreciated.

Quick answer: not likely.

The main thing that would matter would be the total amount of Ca and phos (Ca x phos product), but the body is usually pretty good at regulating Ca via the PTH/bone/kidney axis (although with poorly working kidneys, this is not fully efficient). If the Ca x phos product is really high, it can cause acute issues (vasoconstriction and precipitation of crystals), but it is more often a chronic consideration (i.e., presumably more vascular calcifications).

Each gram of Ca gluconate is only about 2.3 mmol of elemental Ca = about 90 mg of Ca. The ECF holds about 900-1000 mg and there's a big sink in the bone. So you gave less than 1/3 of the normal ECF amount. Since her Ca was low at 7.1 and she was having cardiac issues, I think that it was appropriate to give her Ca (again 2-3 g of gluconate is not that much Ca since gluconate is a large molecule that accounts for most of the mass of Ca gluconate).

Plus, judging from the other labs, I'd bet this person was acidemic. Acidemia displaces Ca from albumin and raises ionized Ca. The patient's total Ca was only 7.1, so I'd bet her iCa was also low, unless her albumin was also very low. We often see ppl getting into problems where as acidemia is corrected, the ionized Ca falls (as more of it gets bound by albumin). So IMHO giving this pt Ca was appropriate. If I was called to dialyze her, I would likely give her a fair amount of Ca with dialysis (since dialysis also fixes acidosis and can further drop iCa).

Out of curiosity, was the phos sky high? Like 15 or something? Is that why the ICU doc had concerns?

 

[GoBuckeyes913]

Agree about the passive-aggressive back handed remarks, unfortunately I get those nonstop (doesn't make it ok, but life of an ED doc. Whadduya gonna do).

Phos ended up being like 9-10 or close to, and lactate was pending. I assumed the patient had acidemia based on the elevated anion gap, therefore also assuming her lactate would be elevated. I knew she wasn't overall getting enough calcium to make a negative difference, but this ICU doc is always condescending (sad because everyone else in his group is amazingly nice and easy to work with). I got pretty much the same numbers when I looked up how much the patient was getting and got confused as to why I got snipped at. Just wanted to make sure I wasn't missing anything. Appreciate the feedback.