Hypokalemia

A low serum potassium concentration is perhaps the most common electrolyte abnormality encountered in clinical practice. When defined as a value of less than 3.6 mmol of potassium per liter, hypokalemia is found in over 20 percent of hospitalized patients. 1 The majority of these patients have serum potassium concentrations between 3.0 and 3.5 mmol per liter, but as many as one quarter have values below 3.0 mmol per liter. Comparable data are not available for outpatients, but a low serum potassium concentration has been found in 10 to 40 percent of patients treated with thiazide diuretics. 2 Hypokalemia is usually well . . .