Potassium, Hypokalemia

DEFINITION
Serum potassium concentration < 3.5 mEq/L

PATHOPHYSIOLOGY
Potassium is the major intracellular cation and thereby largely responsible for maintenance of intracellular volume.
The ratio of intracellular to extracellular potassium concentration is important in determining the cellular membrane potential. Rapid alterations in extracellular potassium concentration alter this ratio and predispose an animal to arrhythmias and conduction disturbances in excitable tissues (e.g., heart, nerve, and muscle)
Hypokalemia can be caused by excessive potassium loss via the gastrointestinal tract or kidneys or movement of potassium from the extracellular fluid compartment into cells (i.e., translocation).