Patho: Potassium/Hydrogen exchange mechanism????!!!

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This is blowing my mind......

PART 1:

In acidosis: Extra Hydrogen goes into the cell and potassium then leaves the cell which causes transient hyperkalemia.

In alkalosis: Hydrogen leaves the cell and potassium enters the cell leading to transient hypokalemia.

The part that is CONFUSING ME!!!!:

PART 2:

--- "In acidosis, hydrogen is excreted and potassium is retained, leading to hyperkalemia."

---"In alkalosis, hydrogen is retained and potassium is excreted leading to hypokalemia:"

Now my question is, in the first part it says H+ enters the cell and K+ leaves, so why in part 2 does it say H+ is excreted and Potassium is retained????????????

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No idea what "excreted" and "retained" is referring to.

In acidosis there are too many hydrogen ions. So the cell will take on some of the extra hydrogen in exchange for potassium. That is why acidosis always goes with hyperkalemia. And vise-versa. As far as I know there is no excretion or retention. The acidosis and alkalosis is not fixed by this process. It just corrects is enough for the person to stay alive.

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Specializes in SRNA.

First of all, is it respiratory acidosis or metabolic acidosis? And when you say that hydrogen is excreted and potassium is retained, where are you referring to? The urine? The ECF? I believe that the kidneys will try to compensate and remove some of the H+ during respiratory acidosis. It seems to me that maybe the first one is talking about respiratory and the second is speaking of metabolic?

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Specializes in Hospital Education Coordinator.

In part I it is referring to what happens on a cellular level, but Part 2 has to do with body waste.

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Part 1 is definitely at the cellular level. I don't believe part 2 makes sense. If you are excreting hydrogen you would no longer be acidotic...

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Part 1 is definitely at the cellular level. I don't believe part 2 makes sense. If you are excreting hydrogen you would no longer be acidotic...

I thought the hydrogen was basic.HCO3 is bicarb. And carbon Is acidic CO2. You would need more hydrogen to hekp correct acidosis

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Hydrogen is an acid. An increase in hydrogen ions causes a low pH and acidosis. A decrease in hydrogen ions causes a high pH and alkalosis.

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What I am confused about is the statement about K+ being retained or excreted opposite hydrogen. In acid base imbalances the lungs and kidneys can help to regulate balance. The lungs can retain or eliminate CO2 (acid), and the kidneys by regeneration, or reabsorption of Bicarb (base). At the cellular level K+ and H+ can exchange like you explained in your part 1. The lungs are the fastest mode for correcting acid base balance, this can happen in as little as minutes to hours. The cellular shifts are the second fastest, this usually takes a few hours. The kidneys take the longest to try to correct any issues (hours-days).

Does anyone have any other information about the potassium excretion or retention leading to the hyperkalemia/hypokalemia? I only know this to be associated with shifts at the cellular level...

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