Normal Serum Level: 3.5-5 mEq/L
Daily Sodium requirement: 1-2 mEq/kg

Hypokalemia ( <3.5 mEq/L)

Types:

  • Mild: 3-3.5 mEq/L
  • Moderate: 2.5 -3.0 mEq/L
  • Severe: <2.5 mEq/L

Causes : Vomiting , metabolic alkalosis, diarrhea, insulin therapy,DKA, malnutrition, diuretic, RTA, salbutamol

Signs: Asymptomatic, Muscle weakness and cramps, paralysis, arrhythmias, polyuria and polydypsia

Pathophysiology:

  • Hypokalemia is either due to potassium loss, transcellular shift or reduced potassium intake.
  • Spurious hypokalemia: Increased WBC in Luekemia or Luekemoid reaction will take up serum potassium.

ECG Changes:
Depressed ST segments, Flattened T wave, Prominent U wave, Ventricular fibrilation and Torsades de pointes

ecg change in hypokalemia

 

Managment:

  • Depends on Potassium level, Clincal symptoms, Renal function, transcellular shift ( insulin therapy, salbutamol nebulization)
  • Potassium is not supplmented when renal function is compromised.
  • Rx:
    • PO
      • Starting: 1-2 mEq/kg/day ; Max: 60mEq in divided dose
      • Poor palatability and tolerance as it is irrtant to gastric mucosa
      • Syp Potklor 15ml = 20mEq Potassium
      • Advice to mix Potklor in water 1/2 or full glass of water or juice
    • IV
      • 0.5- 1 mEq/kg over 1 hour; Max: 40 mEq
        (Adult)
  • Mild
    • Asymptomatic
      • Give potassium rich diet Bananas, Orange and citrus fruits, tomatoes, fruit juices, nuts, coconut oil
    • Symptomatic: Add 0.5ml i.e 1 mEq Inj KCL in 100ml IVF
  • Moderate
    • PO- If child accept orally, give Syp Potklor
    • Sick child- Add 1ml (i.e. 2mEq) KCL in 100 ml IVF (NOTE: Under strict cardiac monitoring)
  • Severe
    • 2.0- 2.5
      • Add Inj KCL 1.5ml (i.e 3 mEq) in 100ml IVF
    • <2.5
      • Add Inj KCL 2ml in 100ml IVF
  • Stop and replace ongoing losses, volume resuscitation with normal saline, correct hypomagnesemia, and treat underlying disease
  • Hemodyliasis:
    • For severe symptomatic hyperkalemia, particularly in patient with impaired renal function or tumor lysis

 

Note: Strict cardiac monitoring is required while giving potassium through IV route.