Comparison of Ringer's acetate and lactate solutions as a prime for cardiopulmonary bypass.

Nineteen patients undergoing myocardial revascularization were randomly given either Ringer's lactate or acetate solution as the prime of cardiopulmonary bypass (CPB), and systemic vascular resistance (SVR) was determined before, and for 10 minutes after, the commencement of CPB. There were no significant differences in SVR or perfusion pressure between the acetate or lactate groups before or during CPB. Blood gas and acid-base values, haematocrit, serum potassium, sodium and ionized calcium concentrations as well as patient temperature were similar in the two study groups. Our results are at variance with some previous experimental findings, which have suggested that acetate has a greater vasodilative effect than lactate.