THE EFFECT OF LOW MOLECULAR WEIGHT DEXTRAN AND HAEMODILUTION ON ACID-BASE BALANCE AND ACTATE AND PYRUVATE LEVELS DURING CARDIOPULMONARY BYPASS

Acid-base changes and lactate and pyruvate concentrations weremeasured in patients undergoing open-heart surgery under totalcardiopulmonary bypass with a Melrose-NEP heart-lung machine.Moderate hypothermia was used. There were no significant differencesin base loss or lactate and pyruvate concentrations betweenperfusions conducted with a whole blood prime and those in whichthe blood was diluted with a low molecular weight dextran withor without the addition of dextrose-saline. The difficultiesin interpretation of measurements of excess lactate are discussed. ^* Present address: University of Alexandria, Egypt.