Paediatric Acute care Guidelines PMH Emergency Department

Hyperkalaemia is defined as a serum potassium (K+) of more than 5.5 mmol/L


  • Serum K+ over 6.5 – 7 mmol/L, especially when associated with ECG changes is potentially life-threatening, and should be treated as an emergency
  • Cardiac toxicity is enhanced by hypocalcaemia, hyponatraemia or acidosis, and patients with these abnormalities may experience complications at lower potassium levels


In children, severe hyperkalaemia may result from:

  • drug ingestions (e.g. digoxin, ACE-inhibitors, oral potassium)
  • acute renal failure
  • massive tissue damage (major trauma or burns, tumour lysis syndrome, haemolysis)
  • severe metabolic acidosis
  • adrenogenital syndromes


  • Perform an ECG
  • Exclude an erroneus high potassium (pseudo-hyperkalaemia) due to haemolysis during collection or transport of the specimen


Clinical features of hyperkalaemia relate to potassium’s effect on cellular membrane polarisation

  • Early symptoms include nausea, vomiting and paraesthesia


Assess for:

  • Muscle weakness, progressing to flaccid paralysis and respiratory failure
  • Cardiac conduction disturbance, resulting in wide complex tachycardia, ventricular fibrillation and circulatory failure


ECG Changes

In acute hyperkalaemia, cardiac conduction disturbance results in ECG changes which correlate roughly with serum K+ levels.

K+ > 6 mmol/L Kgreaterthan6mmol
  • Tall, symmetrical peaked T-waves
K+ > 7.5 mmol/L Kgreaterthan7.5mmol
  • PR interval lengthens (1st degree AV block)
  • Widened QRS (intraventricular block)
K+ > 9 mmol/L Kgreaterthan9mmol
  • Absent P-wave
  • Pre-arrest, QRS and T-waves merge to form a sine wave



  • Hyperkalaemia should be treated when serum K+ is over 7 mmol/L, or at levels lower than this if ECG changes are present
  • Emergency management of hyperkalaemia should include early consultation with the Paediatric Intensive Care Unit (PICU)

Initial management

Step 1: Protect the myocardium from the effects of hyperkalaemia

  • Discontinue any potassium supplement and potassium-containing IV fluids
  • Doesn’t lower the serum K+, but is cardioprotective in that it stabilises the myocardium, reducing the risk of arrhythmias
  • Contraindicated in digitalis toxicity and hypercalcaemia
  • Dose can be repeated after 15 minutes if ECG is still abnormal
  • Can be given as either calcium gluconate or calcium chloride

10% calcium gluconate 0.5mL/kg (maximum 20mL) IV over 2-5 minutes (10% calcium gluconate = 2.2mmol in 10ml)


10% calcium chloride 0.2mL/kg (maximum 10mL) IV over 2-5 minutes


Step 2: Lower the serum potassium level urgently

  • Note: All of  these methods act by shifting potassium intracellularly, thereby reducing the serum K+ level. None of these methods actually reduce total body potassium.
  • Nebulised or intravenous
  • As effective as glucose and insulin
  • Acts within 60 minutes and lasts about 6 hours
5 mg (child > 5 years) or 2.5mg (child < 5 years)

5 micrograms/kg/minute for 1 hour, then 1 microgram/kg/min

  • Similar onset and duration of effect to salbutamol
  • Patients endogenous insulin drives potassium intracellularly

10% glucose at 2mL/kg slow IV bolus

then commence

10% glucose + 0.9% saline infusion at maintenance rate

  • Discuss with a senior doctor before commencing
  • Insulin is only to be given once the glucose infusion has commenced
  • Onset of action 15 minutes
  • Monitor glucose every 30-60 minutes

Insulin short acting infusion at 0.1units/kg/hr

Make up 50 units of Actrapid or Humulin R in 50mL 0.9% saline (1unit/mL).

Prime line with 20mL of solution before commencing the infusion. 

Sodium bicarbonate
  • Discuss with Emergency Department Senior Doctor or PICU prior to use
  • Not routine, but can be used in emergency even in the absence of metabolic acidosis
  • Do not administer via same line as calcium
  • Contraindicated in alkalosis, hypernatraemia
  • Any hypocalcaemia must first be corrected
Infuse at 1 mmol/kg intravenous over 30 minutes
Frusemide  Consider (in consultation with PICU)  1mg/kg (IV)


Step 3: Promote elimination of potassium from the body

Sodium polystyrene sulphonate
(Kayexelate / Resonium)
  • Cease Resonium treatment when the serum potassium is less than 5 mmol/L
    (to avoid hypokalaemia)
Oral dose:
0.5 – 1g/kg (max 60g daily). Administer in a small volume of water or lactulose

Rectal dose: 
0.5 – 1 g/kg (max 30g daily). To administer, mix each 1g of resin with 5mL of water or 10% dextrose.  Irrigate the colon after 8 to 12 hours to remove the resin.

Dialysis  Peritoneal dialysis or haemodialysis  



  • Continuous ECG monitoring is required due to the risk of lethal dysrhythmias

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