All right, so welcome back to the Internet Book of Critical Care podcast. I'm here with Adam Thomas,

and we're going to talk about hypokalemia. This might not make people very upset with us,

which is probably a good thing. I think everyone needs a break, Josh. But this one we deal with

every day. It's very common. and outside of our electrolyte protocols,

we need to know how to top this up.

So let's talk about your approach to hypokalemia and started off with pharmacokinetics.

Just starting out with some basics here.

When we think about repleting patients, potassium, we want to have some concept of how much

potassium deficit that they have, and this can actually be pretty substantial.

So the relationship between potassium deficit and potassium level is probably actually an

exponential relationship. So as you get down to a potassium of two, patients are actually going to have

hundreds of MEQ's deficit. And that can be useful to know so you have some concept of what

you're dealing with. And also, when you're just putting in 10 milo equivalence an hour through a peripheral IV, it's going to take forever to replete that. Exactly.

So let's move into estimation then. So I take a level and all the issues with the laboratory

pseudo-hypochalemia side, how can I estimate based on the level that is reported to me? How many

mill equivalents have to get

into my patient? Yeah, so there's a formula in the chapter. But in addition to the formula,

I think it's useful to think about the clinical scenario. So are there any factors in play

which may be shifting potassium in or out of cells? For example, in diabetic ketoacidosis,

you will start off with patients who are acidotic and the potassium may actually be shifted out of the cells.

So that potassium is going to go way down over time and the actual potassium level is actually

going to underestimate their potassium deficit.

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