Table 3 Differential diagnosis of a metabolic alkalosis (increased SID)

        Gastrointestinal losses: vomiting, gastric drainage, chloride

         wasting diarrhea (villous adenoma)

      Postdiuretic use

      Posthypercapnea

   Chloride unresponsive (urine Cl^- concentration >20 mmol/l)

      Mineralocorticoid excess: primary hyperaldosteronism (Conn's

         syndrome), secondary hyperaldosteronism, Cushing's

         syndrome, Liddle's syndrome, Bartter's syndrome,

         exogenous corticoids, excessive licorice intake

      Ongoing diuretic use

Exogenous sodium load (>chloride)

   Sodium salt administration (acetate, citrate): massive blood

      transfusions, parenteral nutrition, plasma volume expanders,

      sodium lactate (Ringer's solution)

Other

   Severe deficiency of intracellular cations: Mg²⁺, K⁺