5th April 2024

Management

This is almost always done by potassium replacement and the mode of administration and amount of supplementation depends on the severity of hypokalaemia. Any result should be compared with previous results and repeated urgently if inconsistent. 

Oral replacement is appropriate for mild hypokalemia and consists of potassium replacement between 20-40 mmol 2-4 times a day for three days. Potassium rich foods include bananas, tomatoes, avocados, potatoes and apricots. One medium banana contains 12 mmol potassium, the equivalent of one effervescent tablet of sando-K®).

Where oral replacement is not possible, intravenous potassium is used and can be given via a peripheral cannula not exceeding a rate of 10 mmol/hour to avoid phlebitis and discomfort. Monitoring of serum potassium is essential and once ECG abnormalities have resolved the rate of replacement can be further slowed or switched to oral formulations. 

In emergencies, higher replacement rates can be used but must be administered through a central line with continuous cardiac monitoring. The maximum replacement rate should be 0.5 mmol/kg/hour with the weight capped at 80 kg. For example, in an 80 kg adult, the maximum rate of replacement in an emergency via a central line would be 40 mmol/hour. Potassium chloride should never be bolused as it can result in fatal arrhythmias.