Hypokalemia

Hypokalemia

• <3.5 mmol/L
• Severe < 2.5 mmol/L
• ECG changes
  • ST depression
  • U wave
  • QT prolongation (>450 ms)
  • PVCs
  • AV block
  • Bradycardia
  • Vtach
  • Vfib
• Treatment- Replacement
  • Each 10 mEq raises K 0.1 mmol/L
  • PO replacement preferred
  • ECG changes require admission and IV + oral replacement.
  • Magnesium replacement is also indicated.
  • Many foods contain potassium. Replacement need not be tablets only. See list here.
• Symptoms
  • Muscle cramps
  • Muscle weakness
  • Ileus
• Causes
  • Insulin administration shifts K+ into intracellular space
  • Albuterol administration
  • Metabolic alkalosis ( 0.1 increase in pH = 0.5 mmol/L decrease in K+ )
  • Alcohol abuse
  • Vomiting, Diarrhea
  • Diuretic use
  • Hypercalcemia
  • Hypomagnesemia
  • Verapamil (with overdose)
  • Quetiapine (particularly in overdose)
  • Ampicillin, carbenicillin, high-dose penicillins
  • Bicarbonate
  • Antifungal agents (amphotericin B, azoles, echinocandins)
  • Gentamicin

References & Resources:

1. Wiki EM – Hypokalemia
2. Medscape – Hypokalemia
3. Health.gov – Food Sources Of Potassium
4. Mayo Clinic – Potassium Rich Foods
5. Nutrition and Food Web Archive Potassium Converter (mg to mEq)
6. EM:RAP Episode – Electrolytes Part 1
7. Life In The Fastlane – Hypokalemia