ABSTRACT
Potassium-depletionalkalosis is that typeofmetabolic alkalosis causedbydepletion of total body Kþ and corrected solely by the administration of a sufficient amount of Kþ. Hypokalemia (defined by a plasma [Kþ] of < 3.5mEq=L)—by contrast-is present in metabolic alkalosis of any type as well as in some types of metabolic acidosis (1). Hypochloremia is also the rule in Kþ-depletion alkalosis but administration of Cl without Kþ, for example, NaCl, exacerbates rather than corrects theKþ depletion (2,3). The term, ‘‘chloride-resistant alkalosis,’’ is oftenused todescribeKþ-depletionalkalosis but that term fails to emphasize the specific underlying pathophysiology of the majority of the disorders grouped under this rubric. Potassium-depletion alkalosis may occur together with other causes of metabolic alkalosis, most commonly Cl depletion (see Chapter 17). As with other types of metabolic alkalosis, it may be divided into three phases-generation,maintenance, and correction (4) although the generation and maintenance phases may be difficult to separate. In contrast to Cldepletion alkalosis, urinary [Cl] is consistently >20 mEq=L whereas urinary [Kþ] vary depending on the cause of the Kþ depletion.
