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Severe hyperkalaemia has been defined in this context as plasma potassium of ≥6.5 mmol/L
- 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 artifact 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 Kidney 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 suggests 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
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) UK Kidney Association. Clinical Practice Guidelines - Management of Hyperkalaemia in Adults. October 2023.
(3) NICE (February 2020). Patiromer for treating hyperkalaemia