From the Research
Potassium repletion in dialysis patients with hypokalemia should be approached with extreme caution and typically at lower doses than in patients with normal renal function. For mild to moderate hypokalemia (K+ 3.0-3.5 mEq/L) in a stable dialysis patient, oral potassium supplementation with potassium chloride 10-20 mEq once daily or potassium bicarbonate 10-20 mEq daily can be used with close monitoring, as suggested by 1.
Key Considerations
- For severe hypokalemia (K+ <3.0 mEq/L) or in symptomatic patients, intravenous potassium at reduced doses of 10 mEq over 1-2 hours may be given in a monitored setting with frequent potassium checks, as seen in 2.
- The total daily dose should generally not exceed 40 mEq.
- Potassium levels should be checked before each dialysis session and 4-6 hours after supplementation.
- The underlying cause of hypokalemia should be investigated, including medication review, gastrointestinal losses, or inadequate dietary intake.
- Dialysis patients lack the normal renal excretion mechanism for potassium, so they can rapidly shift from hypokalemia to dangerous hyperkalemia with excessive supplementation.
- The dialysate potassium concentration may also need adjustment temporarily to 3-4 mEq/L to prevent further potassium losses during treatment, as noted in 3 and 4.
Recent Evidence
The most recent study 1 from 2022, a randomized controlled trial, found that protocol-based oral potassium treatment to maintain a serum potassium concentration in the range of 4-5 mEq/L may reduce the risk of peritonitis in patients receiving peritoneal dialysis who have hypokalemia.
Clinical Implications
Given the potential risks and benefits, the decision to replete potassium in a patient on dialysis with hypokalemia should be made on a case-by-case basis, taking into account the severity of hypokalemia, the patient's overall clinical condition, and the potential risks of hyperkalemia, as highlighted by 5 and 4.