Hello, you're listening to the podcast Surgery I-C. Rounds. My name is Dr. Jeffrey Guy.

I'm a decision professor of surgery and director of the burn unit at Vanderbilt University School of Medicine.

Today I want to talk about potassium, as it seems to be a very common problem that we have to take care of in basically all kinds of ICU patients, surgical, medical

trauma, burn, cardiac surgical patients. And it's a common problem that occurs not only in

intensive care units, but certainly outside of intensive care units. The vast majority,

98% of all the body's potassium potassium is actually found inside the cell.

It is the most abundant intracellular cationion, and it's the major factor affecting the

osmolality inside the cell.

potassium clearly has a role in a lot of very important functions, such as muscle contractions,

heart contractions, nerve conduction of impulses, and the action potentials are really dependent as well as the muscle contractions

as the ratio between the extracellular potassium and the intracellular potassium.

In the body, the vast majority of the intracellular potassium is found inside the muscle cells.

The total potassium in a 70 kilogram individual is about 3,500 mil equivalents.

Often when there is actually an alteration in a serum potassium concentration,

that may not actually represent a decrease

in total body potassium. It may represent a movement of potassium from an extracellular back into the cells.

But when there is a true alteration in extracellular potassium measured by a decrease or an increase measurement

of the serum potassium.

A change of serum potassium of one mil equivalent indicates a change in total body potassium

of roughly to 100 to 200 mill equivalents of potassium.

This is an important number to keep in mind

that when you have somebody has very little levels of potassium,

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