See also

Resuscitation: Care of the seriously unwell child

Resuscitation: Hospital management of cardiopulmonary arrest

Intravenous fluids

Electrolyte abnormalities

Background

• Hyperkalaemia: serum K+ >5.5 mEq/L, (N range = 3.5-5.0 mEq/L), or  >6.0 mEq/L in neonates
• Hyperkalaemia is potentially life threatening, and can result in cardiac arrhythmias and sudden death

Causes:

• Hyperkalaemia as an artefact of collection process or technique
• Decreased excretion (frequent cause)
  • Renal diseases: Acute/chronic renal failure, renal anomaly
  • Adrenal mineralocorticoid deficiency
• Transcellular shift
  • Acidosis  eg Diabetic ketoacidosis, lactic acidosis
• Increased production (Most often if in association with renal dysfunction)
  • Extensive trauma, rhabdomyolysis (crush injury, convulsion, infection), haemolysis, tumour lysis syndrome, burns
• Exogenous source
  • Iatrogenic potassium administration (oral, IV)
  • Increased ingestion
  • Massive transfusion
• Medication
  • eg NSAID, trimethoprim, heparin, chemotherapy, K-sparing diuretic, ACE inhibitor, beta blockers, succinylcholine, digoxin, mannitol

Assessment

History and examination:

• Look for possible causes (see above)
• Hyperkalaemia can be initially asymptomatic or can presents with severe symptoms/signs:
  • Respiratory depression
  • Palpitations, arrhythmia, cardiac arrest
  • Paraesthesia, flaccid paralysis
  • Ileus
• Confirm that potassium in IV fluids and oral potassium supplements are stopped
• Assess the patient's medication list - stop drugs that increase potassium or reduce its excretion

Investigation and monitoring:

Note: Patients with moderate or severe hyperkalaemia need continuous cardiac monitoring and IV access

• Level of potassium should be confirmed with a second sample
  • If patient has renal dysfunction (renal failure or other renal disease), assume potassium level correct until proven otherwise
  • Acute increase of potassium is associated with higher risk of arrhythmia
• Do an ECG to identify conduction disturbance:
  • Peaked T wave (early)
  • Prolonged PR, flattening of P wave, widening of QRS (increased risk of arrhythmia)
  • Absence of P wave, sine wave (fusion of QRS and T wave)
  • Ventricular arrhythmia, asystole

Note: A normal ECG does not exclude risk for arrhythmia, as life threatening arrhythmia can occur without warning

• Complete investigations and consider causes of hyperkalaemia:
  • Urea, creatinine and electrolytes
  • Glucose
  • Venous blood gas
  • +/- Urine analysis and urinary electrolytes
• Consider other investigations depending on cause:
  • CK
  • Cortisol, aldosterone and hormonal precursor levels (particularly if hyponatraemic)
  • Level of digoxin (if relevant)

Treatment 

If pulseless arrhythmia, see Resuscitation

***Stop any source of potassium intake - IV fluid, parenteral alimentation, dietary supplement (including NGT feeding) and any potassium-sparing medication

Severe hyperkalaemia

- K+ >7.0 mEq/L or at risk of increasing and/or
- Patient symptomatic and/or
- ECG disturbance:

• Calcium IV
• Salbutamol neb
• Insulin/glucose IV
• Bicarbonate IV if metabolic acidosis
• Dialysis:
  • Urgent if unstable
  • Rapid if stable but symptomatic or abnormal ECG
  • Consider if asymptomatic but severe hyperkalaemia
• Resonium (Polystyrene sulfonate) PR (if dialysis unavailable)

Consider hydrocortisone 1-2 mg/kg IV if suspicion of adrenal insufficiency

Moderate hyperkalaemia

- K+ 6-7 
- Patient asymptomatic
- Normal ECG

• Salbutamol neb
• Insulin/glucose IV
• Resonium (Polystyrene sulfonate) PR or oral
• Bicarbonate IV if metabolic acidosis

Mild hyperkalaemia

- K+ >5.5 
- Patient asymptomatic
- Normal ECG

• Consider no treatment
• Stop K supplements
• Recheck result
• Salbutamol neb
• Polystyrene sulfonate PR or oral (resonium)
• Bicarbonate IV if metabolic acidosis

Therapies:

Calcium: 

2 solutions :

Salbutamol:

• Salbutamol: nebulisation
  • Less than 25 kg : 2.5 mg neb 1-2 hourly
  • More than 25 kg : 5 mg  neb (Adu max 10-20 mg) 1-2 hourly
• Salbutamol : IV *Only if severe hyperkalaemia after discussion with senior doctor from tertiary centre with monitoring for tachycardia

Onset of Action: 30 minutes
Duration: 2-3 hours

Insulin/glucose 

to be given at the same time

If severe hyperkalaemia:

• Dextrose 10% :  5 mL/kg IV bolus (if no hyponatraemia)
• Insulin short action: 0.1 U/kg IV bolus  (max 10 units)

Then followed by infusion insulin/glucose (see below)
 
If moderate hyperkalaemia:

• Dextrose 10% IV at maintenance with 0.9% sodium chloride (normal saline)
• Insulin short action infusion : 0.1 U/kg/h IV

Note: Close monitoring of glucose every 30-60 minutes

Onset of Action: 15 minutes
Duration:  peak 60 minutes, 2-3 hours

Bicarbonate 
In metabolic acidosis only

Severe hyperkalamia and metabolic acidosis

• Sodium Bicarbonate 8.4% 1 mmol/mL : 1-3ml/kg IV over 5 minutes

Mild to moderate hyperkalaemia and metabolic acidosis:

• Sodium Bicarbonate 8.4% 1 mmol/mL : 1 mL/kg slow IV infusion over 30 minutes

Note: Do NOT give simultaneously with Calcium
Onset of Action: 30-60 minutes
Duration: 2-3 hours

Dialysis

To be organised with local paediatric renal or intensive care team. Transfer to tertiary centre

Resonium

Mild effect, multiple doses necessary, may be used as long term agent

• Polystyrene sulfonate (resonium) 0.3-1 g/kg 6 hourly (max 15-30 g) PR or oral (with lactulose)

Note:  NOT to be used if ileus, recent abdominal surgery, perforation, hypernatraemia
Onset of Action:  1 hour PR, 4-6 hours oral
Duration: variable

Consider consultation with local paediatric team

• Any child with moderate or severe hyperkalaemia
• Underlying medical cause - eg renal abnormalities

When to consider transfer to tertiary centre

• Any child with severe hyperkalaemia
• Any child requiring dialysis  
• Child requiring care beyond the comfort level of the hospital

For emergency advice and paediatric or neonatal ICU transfers, call the Paediatric Infant Perinatal Emergency Retrieval (PIPER) Service: 1300 137 650.

Last updated March 2016