management of severe hyperkalaemia

Last edited 02/2020 and last reviewed 01/2022

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Severe hyperkalaemia has been defined in this context as plasma potassium of greater than 6.4 mmol/litre.

• it is considered as a life threatening condition due to its serious cardiac and neuromuscular effects (e.g. - cardiac arrest and paralysis of the respiratory muscles)
• urgent treatment is warranted in the following patients
• serum potassium concentration of greater than 6.5 mmol/l regardless of ECG changes
• serum potassium concentration of greater than 6.0 mmol/l with ECG changes
• pre-emptive treatment is also recommended in the following patients:
• rapid rise of serum potassium
• the presence of significant acidosis
• rapid deterioration in renal function (1)

Management of severe hyperkalaemic patient involves the following steps:

• clinically assess the patient
• check that the potassium level is not an artefact e.g. that the sample was not haemolysed
• stop any infusions containing potassium or drugs causing potassium retention
• obtain an ECG and place on constant monitoring
• immediate treatment principals include:

• protect the heart - to reduce arrhythmias
• calcium chloride, 10 mL of 10% solution IV over 5 to 10 minutes, or calcium gluconate, 30 mL of 10% solution IV over 5 to 10 minutes
• has no effect on plasma potassium concentration
• beneficial ECG changes can be seen after 1-3 minutes of administration and the effect can last for 30-60 minutes
• dose could be repeated if follow up ECG after 5 minitues continues to show signs of hyperkalaemia
• calcium is known to potentiate cardiac toxicity of digoxin, hence caution should be exercised in administering calcium to patients taking digoxin
  
  
• shift potassium into cells
• insulin-glucose (10 units soluble insulin in 25g glucose) by intravenous infusion
• hypokalaemic effect of this treatment can be seen within 20 minutes, peaking between 30 and 60 minutes, and it may last for 6 hours
• effect is temporary and hence requires a slow continuous infusion and frequent capillary blood glucose (CBG) monitoring
• nebulised salbutamol -
• at a dose of 10-20 mg diluted in 4 ml of normal saline, given through a nebuliser
• effect may be seen in 30 minutes, with maximum effect at 90–120 minutes.
• can be used alone or to augment the effect of insulin
• UK renal association recommends that salbutamol should not be used as monotherapy in the treatment of severe hyperkalaemia
•  intravenous sodium bicarbonate (500 ml of a 1.26% solution [75 mmol] over 60 minutes)
• although often used for treatment, its benefit is uncertain and routine use for treatment of hyperkalaemia remains controversial
  
  
• remove potassium from the body
• cation-exchange resins are not used in the emergency treatment of severe hyperkalaemia (1,2)
• patiromer
• NICE suggest that (3):
  • patiromer is recommended as an option for treating hyperkalaemia in adults in emergency care for acute life-threatening hyperkalaemia alongside standard care
  • noted that patiromer would not replace intravenous insulin and glucose, but it might replace calcium resonium
  (3)
        

Once the patient is stabilised:

• avoid potassium sparing or retaining drugs e.g. potassium sparing diuretics (e.g. frumil), beta-blockers, ACE inhibitors, NSAIDS, aspirin
• a low potassium diet

Notes (1):

• the threshold for emergency treatment varies, but most guidelines recommend that emergency treatment should be given if the serum K+ is >= 6.5 mmol/L with or without ECG changes

Reference:

• (1) Nyirenda MJ et al. Hyperkalaemia. BMJ. 2009;339:b4114. 
• (2) The Renal Association UK (March 2014). The management of hyperkalaemia in adults.
• (3) NICE (February 2020). Patiromer for treating hyperkalaemia