Hyperkalaemia

Usual intake of [K+] is approximately 1mmol/kg/day, but homeostasis can be maintained at intakes of 20-500 mmol in those with normal renal function.

Remember acute causes of altered homeostasis and elevation:

• Hyperglycaemia (by osmotic effect and by insulin deficiency)
• Acidaemia
• Aldosterone deficiency (including spironolactone, ACE inhibitors)
• Digoxin toxicity
• K supplements + K-sparing diuretics

Treatment of acute hyperkalaemia

Intravenous calcium (if there are ECG changes)

10% gluconate or chloride, 10mls over 5 minutes (maximum 2mls/min)

• Give if ECG changes - peaked T-waves, prolonged PR
• Check in 15 minutes and if still abnormal, repeat once or twice
• Does not change [K+]; reduces excitability of membranes

Intravenous dextrose

25g (e.g., 50ml 50%) + 5u Actrapid over 20 minutes (ie, maximum ratio of 5g :1 unit)

• Acts in 30 minutes, peak effect 90 minutes, lasts up to 6 hours
• Lowers [K+] by 0.7-1.6mmol/l
• Can be followed by slow infusion of 10-50% dextrose (give insulin only if glucose high)

Salbutamol

• 5mg nebulised (or an IV preparation can be given IV)
• Acts in 60 minutes, peaks 90 minutes, lasts up to 6 hours
• Similar to dextrose in efficacy

Sodium bicarbonate

• Traditionally 50ml of 8.4%; but usually as1.26%
• Can reduce [K+] by 0.2-0.3mmol/l but involves sodium load
• Not routine but may be useful in emergency

Dialysis

• Note that above treatments do not remove, they only redistribute [K+]
• A standard haemodialysis removes 40-60mmol [K+]
• Removal of [K+] by haemofiltration or peritoneal dialysis is much slower

Calcium resonium

• Not useful in acute setting but may be short/medium term option if dialysis not desirable or possible. Causes constipation.

Diet

• May explain acute hyperkalaemia; important for prevention, see Diet

 See also the section on perioperative management of [K] - under surgery

Liam Plant was the main author for this page. It was last amended Thursday, November 30, 2006.

NOTE that the accuracy of any statements in this information CANNOT be guaranteed. It is published in the belief that it is correct, and we endeavour to keep it so - but we do make mistakes. Furthermore, over some subjects there are differing opinions, or differing degrees of certainty. We have usually not attempted to discuss these here because the aim has been to provide an immediate and brief guide. In all areas, prior medical knowledge is assumed. The EdRenHANDBOOK is not suitable for use by those without such a background. Contact us by email or at the address given at the foot of the contents page with any comments or corrections.