The effect of acute haemodilution during cardiopulmonary bypass on blood calcium, pH, phosphorus and protein values.

The changes in total serum calcium, ionized calcium, total serum protein, albumin and phosphate levels during cardiopulmonary bypass were measured. The possible causes of the changes in these parameters are discussed. The effect of the presence of heparin on serum ionized calcium is evaluated. The metabolic and clinical significance of the changes in blood components measured are discussed, special attention being paid to the use of calcium as an inotropic agent at the termination of cardiopulmonary bypass.