Management: Potassium Shift

The next step is effectively to hide the potassium intracellularly, bringing the serum potassium level down, and reducing the serious complications that serum hyperkalaemia can lead to.

A recent Cochrane review found that salbutamol and IV insulin-dextrose appear to be the most effective at reducing serum potassium [9]. Sodium bicarbonate can be effective in metabolic acidosis but is not necessary if the bicarbonate is normal.

Insulin-Dextrose

Dose: 10 units of short acting insulin (such as Actrapid) in 50ml 50% dextrose over 15-30 minutes

If the blood glucose levels are already high, insulin can be given intravenously without the dextrose carrier however close glucose monitoring should be undertaken.

Complications: hypoglycaemia

Blood glucose levels should be monitored every 15 minutes for 1 hour then hourly over the next 5 hours following insulin administration to ensure any resulting hypoglycaemia is identified and treated.

Salbutamol

Dose: 10-20mg nebulised

Complications: tachycardia, inconsistent response

As many as 40% of patients seem to be resistant to the hypokalaemic effect of salbutamol, and therefore it should never be used as a single agent for the urgent treatment of hypokalaemia [8].

Sodium Bicarbonate

Dose: 100-150ml of 8.4% sodium bicarbonate over 3-4 hours

Complications: metabolic alkalosis

There isn’t a great deal of evidence surrounding the use of sodium bicarbonate in the management of hyperkalaemia. It can be used to drive potassium intracellularly in the context of metabolic acidosis, and there may be some role in potassium excretion also. Intensive care or nephrology advice should be sought before using bicarbonate, particularly in dialysis-dependent patients.