Abstract: A balanced oncotic pressure fluid suitable as a dialysate in the treatment of patients suffering from loss of kidney function. The solution comprises on the basis of 1 liter of solution about 200-300 mEq sodium, about 145-215 mEq chloride, about 55-85 mEq bicarbonate or acetate or lactate, and about 2-10% by weight dextran, the ratio of sodium to chloride being about 1.4:1. An example of the above solution contains about 224 mEq sodium, about 164 mEq chloride, about 72 mEq acetate, about 6% by weight dextran, about 2% dextrose, about 7 mg zinc gluconate, about 2 mEq potassium, about 3 mEq calcium, and about 2 mEq magnesium.