Hyperkalaemia

Question 1

What is the main complication of hyperkalaemia?

Answer 1

Cardiac arrhythmias eg ventricular fibrillation which can lead to cardiac arrest

Question 2

What are normal serum potassium levels?

Answer 2

3.5-5.3 mmol/l

Question 3

What conditions can cause hyperkalaemia?

Answer 3

AKI
CKI
Rhabdomyolysis
Adrenal Insufficiency
Tumour lysis syndrome

Question 4

What medications can cause hyperkalaemia?

Answer 4

Aldosterone antagonists eg spironolactone

ACE inhibitors eg ramipril

Angiotensin II receptor blockers eg candesartan

NSAIDs eg. naproxen

Question 5

How does hyperkalaemia impact ECG?

Answer 5

(Go, Go long, go wide, go tall):

Flattened/absent P waves
Prolonged PR interval
Broad QRS complexes
Tall T waves

Question 6

What level of hyperkalaemia is considered an emergency?

Answer 6

Over 6.5 mmol/l

Question 7

True of false: it is easier for depolarisation with hyperkalaemia?

Answer 7

True
Increased K+ decreases threshold for action potential so easier depolarisation

Question 8

How do you treat hyperkalaemia very urgently?

Answer 8

IV calcium gluconate
(stabilises cardiac muscle cells, reduces risk of arrhythmias)

Question 9

How do you treat hyperkalaemia non-urgently?

Answer 9

Insulin and dextrose

Insulin drives K+ from extracellular to intracellular space

Dextrose is needed to prevent hypoglycaemia while on insulin

Question 10

What are other options for lowering serum potassium?

Answer 10

Nebulised salbutamol

Oral calcium resonium (reduce K+ absorption, causes constipation)

Sodium bicarbonate in acidotic patients

haemodialysis