Abstract: A sterilizable aqueous solution with substantially physiological values of the pH, bicarbonate concentration and CO.sub.2 partial pressure, as well as with metabolizable anions in the form of two separately stored single solutions, which are combined with one another prior to use and whereof one is a bicarbonate-free, acid solution and the other a bicarbonate-containing, alkaline solution, is characterized in that per liter of the finished solution obtained by combining the two single solutions, the acid single solution contains 7.3 mmole.+-.3% of at least one metabolizable, organic acid and the alkaline single solution 19.1 mmole.+-.3% of alkali bicarbonate and 6.1 mmole.+-.3% of alkali carbonate.