Overview of Metabolic Alkalosis VIDEO Etiology Metabolic alkalosis is bicarbonate (HCO 3 −) accumulation due to Acid loss Alkali administration Intracellular shift of hydrogen ion (H + —as occurs in hypokalemia) Renal HCO 3 − retention Regardless of initial cause, persistence of metabolic alkalosis indicates that the kidneys have increased their HCO 3 − reabsorption, because HCO 3 − is normally freely filtered by the kidneys and hence excreted.