Hypokalemia

Hypokalemia EMRAP June 2025

Anand Swaminathan, MD and George Willis, MD

Dr. Anand Swaminathan and Dr. George Willis take a deep dive on hypokalemia. Their conversation will take your management of hypokalemia to the next level. Part 1 covers the clinical presentation of hypokalemia and potassium repletion.

  • Clinical Presentation
    • Patients may complain of fatigue or feeling run down.
    • Cardiac effects include dysrhythmias, including torsades.
    • There may be neuromuscular weakness and, in extreme cases, paralysis or rhabdomyolysis. 
  • Potassium Repletion
    • There is no significant difference in efficacy between different forms of potassium:
      • May administer potassium bicarbonate or potassium citrate in the acidotic patient
      • May opt to avoid potassium chloride in the hyperchloremic patient
      • May administer potassium phosphate in the hypophosphatemic patient
    • 10 mEq of potassium repletion results in a 0.1 mEq/L change in serum potassium level.
      • Potassium levels <3.0 mEq/L will require much larger amounts of repletion to affect serum levels.
    • Oral repletion
      • Preferred method of repletion
      • Best suited for mild hypokalemia (>3.0 mEq/L) 
      • Can give 40-60 mEq/hour 
    • Peripheral IV lines
      • Best suited for PO-intolerant patients or levels <3.0 mEq/L
      • Maximum rate of 10 mEq/hour to avoid painful irritation to small veins
      • Can achieve faster rates by giving through multiple IVs or mixed into IV fluids
    • Central venous lines
      • Reserved for profound hypokalemia and unstable patients
      • As fast as 80 mEq/hour 
      • Patients should be on continuous cardiac monitoring 
    • For patients in cardiac arrest secondary to hypokalemia, you can push 40 mEq of potassium chloride through a peripheral IV.
    • Recheck potassium levels at least 1 hour after IV repletion to allow time for intracellular shifts.
  • Magnesium Repletion
    • Hypomagnesemia results in renal potassium wasting.
    • IV, rather than oral, magnesium repletion is required for hypomagnesemic patients.
    • Magnesium levels of 1.0 or less:
      • Give 4 g of magnesium prior to potassium repletion
    • Magnesium levels of 1.5 or higher:
      • Give 1-2 g of magnesium prior to potassium repletion
  • Disposition
    • ICU indications
      • Patients with neuromuscular complaints – require monitoring for diaphragmatic involvement and respiratory compromise
      • Severe ECG findings, including non-sustained ventricular tachycardia, multiple premature ventricular contractions (PVCs), torsades, or prolonged intervals
      • Level-specific hospital policy
    • Admission
      • Patients with levels <2.8 mEq/L will require ~30 mEq to cause 0.1 mEq/L change in serum potassium level
      • Moderate to severe cases where a cause has not been identified
    • Discharge home
      • Patients with levels >3.0 mEq/L and mild symptoms can be discharged without repeat level after repletion.
      • Patients with levels of 2.8 to 3.0 mEq/L can be discharged after repletion and a repeat level.
      • If patients are taking thiazide or loop diuretics, consider starting low-dose potassium supplementation with close follow-up
      • Counsel patients regarding high-potassium foods (eg, banana, orange juice, sweet potato, avocado).