Total body potassium depletion is present in patients with diabetic ketoacidosis (DKA) despite having normal or elevated serum potassium levels Hyperkalemia should be confirmed to rule out pseudohyperkalemia due to a hemolyzed sample Severe hyperkalemia may lead to cardiac arrhythmias, and initial treatment is aimed at stabilizing the myocardium with IV calcium Subsequent treatment of hyperkalemia involves enhancing intracellular movement of potassium, followed by removal of excess potassium from the body Hypokalemia Hypokalemia is defined as a measured serum potassium concentration below 3.5 mEq/L Hypokalemia may result from total body deficit, transcellular shift of potassium to the intracellular space, or a combination of both processes There are numerous causes of hypokalemia including renal loss, extrarenal loss, and increased cellular uptake, which are outlined in Table 100.7 The common causes of hypokalemia seen in pediatric EDs are those due to gastrointestinal loss, diuretic use, and DKA Metabolic alkalosis will also lead to hypokalemia due to transcellular shift of potassium to the intracellular space For every 0.1 unit rise in blood pH, serum potassium would be expected to decrease by approximately 0.4 to 0.6 mEq/L