Hypokalemia hypochloremic metabolic alkalosis

Causes of Hypokalemia

• Intracellular shift of K⁺:

  • Insulin

  • β-adrenergic stimulation

  • Hematopoiesis

• Gastrointestinal losses

• Renal potassium wasting:

  • Hyperaldosteronism

  • Diuretics

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Hypokalemic Metabolic Alkalosis in Normotensive Patients

Always consider:

1. Surreptitious vomiting

   • Clues: dental erosions, calluses/scars on dorsum of hands (Russell sign).

   • Labs: low urine chloride (due to hypovolemia + hypochloremia).

2. Diuretic abuse

   • Labs: high urine chloride (drug effect).

   • Can mimic Bartter/Gitelman.

3. Bartter syndrome (defect in loop of Henle)

   • Childhood onset, normal BP.

   • High urine chloride, metabolic alkalosis, hypokalemia.

4. Gitelman syndrome (defect in distal tubule, thiazide-like)

   • Adolescence/adulthood, normal BP.

   • Hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis.

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Key Distinction

• Urine chloride helps differentiate:

  • Low: vomiting

  • High: diuretics, Bartter, Gitelman

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✅ Memory hook:

Hypokalemia + Alkalosis + Normotension → think "VD-BG" (Vomiting, Diuretics, Bartter, Gitelman).

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managemant :

++ Normal saline also restores intravascular volume and helps treat hypokalemia by normalizing aldosterone levels.

++Acetazolamide is sometimes used to improve metabolic alkalosis when additional fluid volume cannot be tolerated in patients with heart failure.

++Vomiting and nasogastric suctioning in patients with small bowel obstruction lead to hypokalemic, hypochloremic metabolic alkalosis due to the loss of H⁺ and chloride (Cl⁻) via gastric fluids.  Administration of intravenous normal saline (NaCl) replenishes Cl⁻ stores to facilitate HCO₃⁻ excretion, thereby treating metabolic alkalosis.