Hyperkalaemia

increased Potassium in the blood
treat as emergency as risk of cardiac arrythmia

Treatment

Protect myocardium
- 10ml of calcium gluconate 10%
Drive K⁺ into cells
- Insulin 10-20 U + 50ml of 50% glucose over 20-30mins
Deplete body K⁺
- calcium or sodium resonium
  - 15g orally TDS + laxatives
  - 30g rectally + enema
- Haemodialysis / Continuous Ambulatory Peritoneal Dialysis
Correct severe Metabolic Acidosis if necessary
- 50mls sodium bicarbonate 8.4%

Causes

Artefacts
- Wrong Patient
- Contaminant
- Haemolysis
- Wrong container
- Delay
- Communication error
- Lab Error
Increased intake of potassium
- Potassium chloride
  - IV
  - oral
    - salt substitutes
- Potassium citrate
- Transfusion of stored blood
Movement from cells to ECF
- Acidosis
- Diabetic Ketoacidosis
- Rhabdomyolysis
- Tumour Lysis
- succinylcholine / suxamethonium
- digitalis overdose
- severe exercise
- insulin deficiency
- hyperosmolality
- tissue catabolism
- beta-adrenergic blockade
- periodic paralysis
Decreased urinary excretion
- renal failure
- drugs
  - direct effects
  - indirect
- hypoaldosteronism
  - Addison's Disease
  - Hyporeninaemic hypoaldosteronism (type IV renal tubular acidosis)
- selective potassium secretory defect
- Gordon's Syndrome
Spurious
- increased in vitro release from abnormal cells
  - Leukaemia
  - Infectious Mononucleosis
  - Thrombocytosis
  - Familial pseudohyperkalaemia
- vigorous fist clenching during phlebotomy

Clinical Features

may be asymptomatic
muscle weakness
decreased cardiac excitability
- hypotension
- bradycardia
- asystole
if accompanied by Metabolic Acidosis
- Kussmaul breathing

Investigations

U&Es
ECG changes
1. reduced P wave with increased QRS
2. tented T wave
3. 'sine wave' pattern (pre-cardiac arrest)

Complications

sudden death from cardiac asystole

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