METABOLIC ALKALOSIS is the process which causes, or tends to cause, a nonrespiratory deficit in extracellular hydrogen ion concentration.
Major Laboratory Characteristics.
—An increased extracellular bicarbonate concentration and an elevated pH are a reflection of the hydrogen ion deficit. In terms of the Henderson-Hasselbalch equation, serum bicarbonate is elevated compared to the hydrated carbon dioxide (H2CO3). The normal 20:1 ratio of is increased and pH is elevated (Fig 1).The elevated bicarbonate in metabolic alkalosis is due to a disturbance in the normal dynamic relationships between the bicarbonate produced in the body and the amount of hydrogen ion formed by metabolic processes. If hydrogen ion is decreased in extracellular fluid, less is available to participate in the reaction and bicarbonate accumulates.Respiratory compensation for metabolic alkalosis is never complete and is relatively ineffective. The Pco2 may be slightly elevated, normal, or decreased.Typical serum electrolyte changes include an