When should I consider referring a patient with severe hypokalaemia to secondary care?

Consider referring a patient with severe hypokalaemia (serum potassium less than 2.5 mmol/L) to secondary care immediately if they are symptomatic, especially with dysrhythmias, paralysis, respiratory failure, or severe weakness.

Also refer urgently if the patient has clinical signs of hypovolaemia, thyrotoxic crisis, hypokalaemic periodic paralysis, metabolic acidosis/alkalosis, hyperosmolar hyperglycaemic state, or diabetic ketoacidosis.

Severe or symptomatic hypomagnesaemia (less than 0.5 mmol/L) alongside hypokalaemia warrants specialist discussion and possible admission.

In asymptomatic patients with moderate hypokalaemia (2.5–2.9 mmol/L), consider referral if there is a concurrent medical condition that increases risk, such as cardiac disease (due to risk of fatal dysrhythmias), renal disease, or hepatic disease (due to risk of hepatic encephalopathy).

Refer urgently if malignant disease is suspected as the cause of hypokalaemia.

If the cause of hypokalaemia is unclear or oral potassium cannot be tolerated, referral to an endocrinologist or appropriate specialist is advised.

Continuous ECG monitoring and serial potassium measurements are important during repletion in secondary care to avoid complications.

These recommendations are based on NICE CKS Hypokalaemia guidelines and expert consensus.