Hyperkalaemia and hypokalaemia Flashcards
What 2 hormones stimulate intracellular potassium transport
Insulin - K+ in cell
Aldosterone - K+ secretion into urine
Causes of hyperkalaemia
Type 4 renal tubular failure - renal failure due to metabolic acidosis
Adrenal failure - Addison’s disease
K- sparing agents - spironolactone and amiloride + ACEi/NSAIDs
Hyperkalaemia presentation
Normally asymptomatic
- muscle weakness
- Kussmaul breathing - metabolic acidosis
- palpitations
- hypotension
- bradycardia
Severe hyperkalaemia
7+ mmol/l
ECG changes for hyperkalaemia
Tall tented T waves Prolonged PR interval Absent P wave Widened QRS Sine wave
Can go into ventricular fibrillation and asystolic arrest
Treatment of hyperkalaemia
10% calcium gluconate - 10 - 20mg (titration till ECG improves)
IV insulin 10 units - with 50ml 50% glucose IV
Nebulised salbutamol
Sodium bicarbonate - acidosis
Investigations for hyperkalaemia
Obs
Bloods - K+, U+Es, LFTs
ECG
Addison’s - synacthen test
Medication review
Severe hypokalaemia
Less than 2.5 mmol/l
Causes of hypokalaemia
Hyperaldosteronism
Thiazide/ loop diuretic overuse
Metabolic alkalosis
Hypokalaemia presentation
Usually asymptomatic
- muscle weakness
- palpitations
Gitelman syndrome
Causes metabolic alkalosis - hypokalaemia
Na+/Cl inhibition - 100% thiazide effect
Barterr syndrome
Metabolic alkalosis
Hypokalaemia
- caused by 100% loop diuretic effect
- defected NKCC2 channel
Liddle syndrome
Metabolic alkalosis
Hypokalaemia
Hypertension
- 100% amiloride effect
- defective ENaC channel
Investigations for hypokalaemia
Obs Bloods - FBC, U+Es, LFTs, K+ ECG ABG - alkalosis? Medication review
Management for hypokalaemia
Treat underlying cause
- withdraw diuretics
Oral or IV K+
