Exchangeable potassium study in patients undergoing chronic haemodialysis.

Seven patients with chronic renal failure treated with haemodialysis for 4 to 24 months were found to have low exchangeable potassium levels. Before dialysis the plasma potassium was normal or somewhat raised (possibly owing to acidosis), though the exchangeable potassium was low. Acidosis was corrected during dialysis; plasma potassium levels fell, but clinical and electrocardiographic changes of hypokalaemia were absent. The level of 1 mEq/litre in the dialysate fluid may be too low for use in prolonged haemodialysis.