Hyperkalemia

[Cknight]

Why is hypertonicity a cause of hyperkalemia? I would imagine it would cause hypokalemia due to an increased offer of sodium to the distal tubule to exchange for K. Any thoughts?

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[LukeWhite]

There's a great NEJM article on Na/K balance from a few weeks back that might help a bit. It's geared towards hypertension pathophysiology but is a great overview in general of the interplay between sodium and potassium.

N Engl J Med 2007; 356:1966-1978, May 10, 2007

 

[phassett74]

Extracellular hypertonicity draws water towards it from intracellular (pulling some K+ with it)

Additionally, with new gradient established, K+ has more gradient to leave intracellular space to enter extracellular

One of those wonderful two phase, osmotic fun fluids deals

If you want more info on it check out "Clinical Physiology of Acid-Base & Electrolyte Disorders" by Burton Rose & Theodore Post - really nice pathophys.

 

[Cknight]

Hey, thanks a lot guys!

 

[southerndoc]

I learned recently that patients on amiodarone have exaggerated effects of hyperkalemia. So if you have a patient on amiodarone who has a potassium of 5.5, treat it aggressively. A potassium of 6 can put them in a sine wave.

 

[fakin' the funk]

i don't know exactly what hyperkalemia is, could somebody explain to me , thank you

Somebody ban this fool quick, his post is obviously an ad.

 

[southerndoc]

Somebody ban this fool quick, his post is obviously an ad.

Done. Thanks for pointing it out. I didn't even see his/her signature line, but anybody who advertises a commercial site in the UK to get Viagra deserves banning in my opinion.

 

[proman]

Found this in Anesthesiology, Volume 93(5)November 2000pp 1359-1361

Dilutional acidosis has been proposed as a possible mechanism of hyperkalemia because of the transcellular movement of potassium after administration of hypertonic mannitol. 1 Maintenance of steady acid-base status, however, does not prevent the increase in plasma potassium concentration. 2-4,8 Two alternative mechanisms that shift potassium out of the cells after mannitol administration have been suggested. First, a solvent drag phenomenon that moves potassium-rich intracellular water into the hypertonic extracellular compartment through the water pores is involved. 2-4,8 Second, the loss of water in the cells, caused by hyperosmolality in the extracellular fluids, increases the intracellular potassium concentration, which creates a favorable gradient for passive potassium exit through potassium channels. 8

 

[werewethere]

Found this in Anesthesiology, Volume 93(5)November 2000pp 1359-1361

Dilutional acidosis has been proposed as a possible mechanism of hyperkalemia because of the transcellular movement of potassium after administration of hypertonic mannitol. 1 Maintenance of steady acid-base status, however, does not prevent the increase in plasma potassium concentration. 2-4,8 Two alternative mechanisms that shift potassium out of the cells after mannitol administration have been suggested. First, a solvent drag phenomenon that moves potassium-rich intracellular water into the hypertonic extracellular compartment through the water pores is involved. 2-4,8 Second, the loss of water in the cells, caused by hyperosmolality in the extracellular fluids, increases the intracellular potassium concentration, which creates a favorable gradient for passive potassium exit through potassium channels. 8

Interesting