All right, welcome back to the Internet Book of Critical Care podcast.

I'm here with Adam Thomas and we're going to talk about all things phosphorus.

We're going to start with hypo, so not enough, and then end it with hyper too much.

So Josh, hypophosphatemia, maybe the more clinically relevant or something you see more of. Let's talk about that.

Yeah, this is tricky, honestly. And I think one challenge here is that all of the evidence is

correlational. So there's lots of evidence that hypophosphotemia correlates with badness.

And then I think the billion dollar question is, does giving phosphorus improve outcomes or

does it just fix the number?

And I don't have a solid answer for that. I do tend to be a bit of a phosphorus believer.

It's involved in a lot of important things like ATP. But ultimately, if folks on the internet

troll us and say, you know, we're throwing a bunch of faucet people for no reason. I don't have a

solid reply to that. What, ATP's important, Josh?

It's not that important. Only if you want to live. Think of the mitochondria. Yeah. All right, guys,

let's talk about phosphate physiology then. Walk me through the basics here because I remember there's

some parathyroid glands. There's a liver. There's some skin. What's going on here?

So first of all, as far as cellular physiology, this is also frustrating.

So 99% of the phosphorus is inside cells.

And that's where it matters. So we need phosphate to be inside of the cells.

The extracellular phosphate level probably doesn't matter at all.

And unfortunately, that's what we measure. And this is

problematic because the patients who are really dying from hypophosphatemia, they're dying from

intracellular hypophosphatemia. So those are patients who probably have chronic hypophosphatemia,

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