What is the mechanism behind hyperkalemia in burn injuries?

• A. Release of potassium from damaged cells
• B. Increased potassium excretion
• C. Potassium shift into cells
• D. Active hypervolemia

Answer: (A)

In burns, tissue destruction disrupts many cell membranes, causing the contents of those cells to spill into the surrounding fluid. Potassium is kept at high levels inside cells, so when cells are damaged, a large amount of potassium is released into the extracellular space and bloodstream. This sudden release raises serum potassium, producing hyperkalemia in the acute phase of burn injury.

It's not about the body excreting more potassium or about potassium moving into cells (that would lower blood potassium). Volume status by itself doesn't drive this spike; the key driver is the leakage of intracellular potassium from damaged cells, often compounded by acidosis from tissue injury.