Causes of Hypokalemia

I. Decreased intake

   A. Starvation

   B. Clay ingestion

II. Redistribution into cells

   A. Acid-base

      1. Metabolic alkalosis

   B. Hormonal

      1. Insulin

      2. Increased ß2-adrenergic sympathetic activity: post-myocardial infarction, head injury

      3. ß2-Adrenergic agonists - bronchodilators, tocolytics

      4. a-Adrenergic antagonists

      5. Thyrotoxic periodic paralysis

      6. Downstream stimulation of Na*/K+-ATPase: theophylline, caffeine

   C. Anabolic state

      1. Vitamin or folic acid administration (red blood cell production)

      2. Granulocyte-macrophage colony-stimulating factor (white blood cell production)

      3. Total parenteral nutrition

   D. Other

      1. Pseudohypokalemia

      2. Hypothermia

      3. Familial hypokalemic periodic paralysis

      4. Barium toxicity: systemic inhibition of "leak" K* channels

Ill. Increased loss

   A. Nonrenal

      1. Gastrointestinal loss (diarrhea)

      2. Integumentary loss (sweat)

   B. Renal

      1. Increased distal flow and distal Na• delivery: diuretics, osmotic diuresis, salt-wasting nephropathies

      2. Increased secretion of potassium

         a. Mineralocorticoid excess

         b. Apparent mineralocorticoid excess

         c. Distal delivery of nonreabsorbed anions

      3. Magnesium deficiency



#Hypokalemia #Differential #Diagnosis #Low #Potassium #Classification #Causes