hypokalaemia

Question 1

Aetiology of hypokalaemia (3)

Answer 1

Decreased intake of potassium
Increased excretion of potassium
- Thiazides + loop diuretics
- Renal disease
- GI loss
- Increased aldosterone (Conn’s syndrome)
Potassium shifted to intracellular
- Insulin
- Salbutamol
- (other drugs)

Question 2

Diagnosis + ECG of hypokalaemia (5)

Answer 2

• Low K+ in U+E
  ECG:
  Go Up: Prominent U waves
  Go Down: Small inverted T waves
  Go Long: Prolonged PR interval
  Go Therapy: ST Depression

Question 3

Effect of hypokalaemia on insulin, pH and beta 2 receptors

Answer 3

• Excess insulin as too much K+ flows into cell
• Alkalosis (H+ out and K+ in)
• B2 agonist - Increase B2 pumping of K+ into cell

Question 4

Effect of hypokalaemia on the 3 types of muscle

Answer 4

• Smooth muscle constipation
• Skeletal muscle weakness and cramps
• Cardiac arrythmias and palpitations

Question 5

Presentation of hypokalaemia (4)

Answer 5

• Hypotonia
• Hyporeflexia
• Arrhythmias (especially AF)
• Muscle paralysis and rhabdomyolysis

Question 6

Treatment for hypokalaemia (4)

Answer 6

• K+ replacement
• Aldosterone antagonist (spironolactone)
• Treat underlying cause
• Other electrolyte defficiencies