Hypokalemia

• • Depressed serum potassium

Epidemiology

• • Alcoholics

  • Elderly

  • Prolonged NPO

  • Hyperaldosteronism

Symptoms and Signs

• • Decreased muscle contractility

  • Paralysis

Laboratory Findings

• • Depressed serum potassium

  • Alkalosis can contribute

  • Hypomagnesemia can contribute to refractoriness

• • Laboratory error or difficulty with phlebotomy; blood drawn from above an IV infusion can have spurious results with very low potassium

Rule Out

• • Hypomagnesemia

• • Serum electrolytes including magnesium

  • ABG (pH) measurement

  • Urine potassium losses: (< 30 mEq/d total body deficit, > 30 mEq/d renal wasting)

  • Plasma renin activity, serum aldosterone measurement

• • Correct underlying problem

  • Potassium repletion

  • Magnesium repletion if necessary

  • Correct alkalosis if present

Medications

• • KCl PO if possible, if IV then 20-30 mEq/h by central vein or 10 mEg/h by peripheral vein

  • MgSO4

Treatment Monitoring

• • Serum potassium

Complications

• • Hyperkalemia

Prognosis

• • Excellent

Prevention

• • Adequate dietary intake or IV supplements

References