HYPERKALEMIA

Question 1

WHAT IS HYPERKALEMIA?

Answer 1

• elevated level of potassium (K+) in the blood.

- levels above 5.5 mmol/L defined as hyperkalaemia.

Question 2

WHAT ARE THE CAUSES OF HYPERKALEMIA?

Answer 2

1) increase K+ intake with decreased renal excretion - K+ rich diet with CKD (potatoes, dried fruit, avocados)
2) decrease potassium excretion - spironolactone, NSAIDs, heparin, ACEi, ARBS, digoxin
3) secondary to conditions - hypoaldosteronism, Addison’s disease, DKA, rhabdomyolysis, tumour lysis

Question 3

WHAT ARE THE 5 ECG CHANGES SEEN IN HYPERKALEMIA?

Answer 3

1) tall peaked T wave
2) prolonged QRS
3) slurring of ST segment
4) loss of P waves
5) asystole

Question 4

WHAT IS THE 3 STEP TREATMENT FOR HYPERKALEMIA AND WHY?

Answer 4

1) 10mls of calcium gluconate over 5- 10 minutes to stabilise myocardium to prevent arrhythmias
2) IV fast acting insulin (actrapid) with 20g glucose + salbutamol 5-10mg via nebuliser to shift potassium into intracellular space
3) Calcium resonium or frusemide or dialysis (if not responsive to medical treatment) to eliminate K+ from body

Question 5

WHAT ARE THE COMPLICATIONS OF HYPERKAELMIA?

Answer 5

1) life threatening arrhythmias

2) severe muscle weakness or paralysis- depolarisation blockade

Question 6

WHAT INVESTIGATIONS SHOULD BE CARRIED OUT FOR PATIENTS PRESENTING WITH HYPERKALEMIA?

Answer 6

1) urine dipstick creatine kinase, if rhabdomyolysis is a possibility
2) cortisol and aldosterone levels, if Addison’s disease is suspected
3) arterial blood gases, if metabolic acidosis needs to be established
4) serum digoxin level, if the patient is receiving digoxin or suicide is known to have been attempted with digoxin ingestion