Potassium metabolism in patients with chronic kidney disease. Part II: patients on dialysis (stage 5).

Potassium is removed mainly by diffusion during dialysis. In hemodialysis, potassium removal averages 70-150 mmol per session, and the presence of glucose-free dialysate, sodium profiling, and hyperkalemia, may increase its removal. The most frequent potassium derangement in hemodialysis patients is hyperkalemia. Hemofiltration removes approximately 60 mmol of potassium per treatment. In peritoneal dialysis patients, despite lower potassium removal (about 30-40 mmol/day), hypokalemia is the most frequent electrolyte alteration, probably due to movement of potassium into the cells mediated by insulin, secondary to glucose absorption from the dialysis solution.