Calcium as an inotrope?

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I have often heard of giving calcium or correcting hypocalcemia with a mind toward increasing inotropy.

Unfortunately, i've now been asked to defend the practice and thus far have been unable to produce any significant evidence for an inotropic effect. I know its out there somewhere, even if perhaps it is not strong. Anyone have a decent reference for this?

Check out some crit care text books. I think your point is commonly made. I think most think of it as an inotrope in the setting of hypocalcemia, CCB OD, citrate tox associated with mass transfusions, etc. In addition to brief inotropy it is quite effective at increasing PVR and thus is an effective pressor.

Iride

Here is a review article with very brief mention to your point: The Use of Vasopressors
and Inotropes in the Emergency Medical Treatment of Shock.
Emerg Med Clin N Am 26 (2008) 759–786

It is a start.

Iride

Which douche is asking you to "defend" this. It's virtually from basic pharmacotherapy theory. Ever heard of calcium release fromt he sarcomere. I would also reference this article to the douchebag who wants to argue:

http://www.ncbi.nlm.nih.gov/pubmed/14684649

Originally Posted by bulgethetwine

Which douche is asking you to "defend" this. It's virtually from basic pharmacotherapy theory. Ever heard of calcium release fromt he sarcomere. I would also reference this article to the douchebag who wants to argue:

http://www.ncbi.nlm.nih.gov/pubmed/14684649

Come on man, how often have axioms based on "basic theory" been proven wrong or clinically inconsequential. Plus, according to that theory, cytosolic [calcium] is low enough that there's sufficient driving force for calcium ions to enter the cell even if the patient is hypocalcemic.

Originally Posted by bulgethetwine

Which douche is asking you to "defend" this. It's virtually from basic pharmacotherapy theory. Ever heard of calcium release fromt he sarcomere. I would also reference this article to the douchebag who wants to argue:

http://www.ncbi.nlm.nih.gov/pubmed/14684649

Ah it's the fellow on my ICU team. We are having a good time going back and forth. In particular with her attacking then me defending various practices that the ER (very agressive here) does that the IM docs (not very agressive here) do not. Other examples being magnesium for asthma/COPD and paralytics. It is all good natured but we both like being right.

Originally Posted by turkeyjerky

Come on man, how often have axioms based on "basic theory" been proven wrong or clinically inconsequential. Plus, according to that theory, cytosolic [calcium] is low enough that there's sufficient driving force for calcium ions to enter the cell even if the patient is hypocalcemic.

Fair point.

But this isn't one of those cases. If I want to send a resident or medical student on a prove-to-me-it-works expedition, I send them on something meaningful. Like using Flolan for pulmonary hypertension. Or giving bicarb "always" for acidosis. I don't send 'em on a fool's errand. Medical education is #****edupenough already.

With all respect it sounds like your fellow is quite junior and/or has skipped out on their reading. Not that these practIces are so well rooted in EBM but more that they are grounded in understanding pathophysiology. Might it be incorrect? Surely. But, is there evidence to support NOT giving calcium to the hypocalcemic patient with LV dysfunction? Definitely not. Same with mag and asthma. Your fellow just sounds simple. Btw, neither of these interventions are particularly "aggressive." Now if you starting ECMO on a big chunk of your asthmatics in the ED, now that would be aggressive.

Iride

Originally Posted by iridesingltrack

With all respect it sounds like your fellow is quite junior and/or has skipped out on their reading. Not that these practIces are so well rooted in EBM but more that they are grounded in understanding pathophysiology. Might it be incorrect? Surely. But, is there evidence to support NOT giving calcium to the hypocalcemic patient with LV dysfunction? Definitely not. Same with mag and asthma. Your fellow just sounds simple. Btw, neither of these interventions are particularly "aggressive." Now if you starting ECMO on a big chunk of your asthmatics in the ED, now that would be aggressive.

Iride

Magnesium in asthmatics is actually pretty evidenced based, at least for reducing need for admission in moderate morbidity pts. I think it also decreases need for ICU but it's been a while since I reviewed the primary literature. Now a question I would love to know the answer to is why giving calcium to a patient on a dilt gtt that becomes hypotension usually fixes the hypotension but doesn't reverse the chronotropic effects.

Originally Posted by logos

I have often heard of giving calcium or correcting hypocalcemia with a mind toward increasing inotropy.

Unfortunately, i've now been asked to defend the practice and thus far have been unable to produce any significant evidence for an inotropic effect. I know its out there somewhere, even if perhaps it is not strong. Anyone have a decent reference for this?

Find an appropriate patient. Check the BP. Give a calcium bolus. Recheck the BP. Capture on your iphone, and send to said fellow.

Originally Posted by Rendar5

Find an appropriate patient. Check the BP. Give a calcium bolus. Recheck the BP. Capture on your iphone, and send to said fellow.

I give calcium pretty routinely in the OR in the setting of frequent and/or mass transfusion. The BP ALWAYS bumps up on the arterial line (sometimes significantly).

The effect is probably transient and I doubt it affects outcomes though.