Moderate Hypokalemia (Serum Potassium 2.5–2.9 mmol/L) in Adults When Oral Potassium Replacement Has Not Worked
This protocol addresses adult patients aged 16 years or over presenting with a confirmed serum potassium of 2.5–2.9 mmol/L (moderate hypokalaemia) whose potassium level has not risen above 2.9 mmol/L following an initial course of oral replacement therapy.
Adult aged 16 or over — serum potassium confirmed at 2.5–2.9 mmol/L. The patient has already received oral potassium replacement, and the target has not been achieved.
The initial approach was oral potassium replacement with Sando-K® (effervescent potassium chloride and potassium bicarbonate tablets). The goal — serum potassium rising above 2.9 mmol/L on at least daily monitoring — was not reached. This failure is the trigger for escalation to the present protocol.
When oral replacement has not corrected moderate hypokalaemia in this range, the next approach involves intravenous potassium supplementation, which must be carried out in a hospital setting. The complete regimen — including solution selection, administration parameters, and the criteria for transitioning back to oral therapy — is set out in the full protocol.
Serum potassium rises above 2.9 mmol/L. Monitoring is required after initial therapy and at least daily until that threshold is confirmed.
- Moderate 2.5 to 2.9mmol/L
- This guideline does not apply to patients under the age of 16.
- When serum potassium is <3mmol/L, intravenous supplementation is usually required.
- This must only be administered in a hospital setting.
- Standard concentration (up to 20mmol/500mL) via peripheral line.
- Maximum rate of administration: 10mmol/hour
- Maximum concentration: 20mmol/500mL
- Change to oral preparations as soon as possible.
- Monitor serum potassium following initial therapy, and then at least daily until serum potassium >2.9mmol/L then manage as above.