Effects of Massive Transfusion of Blood on Acid-Base Balance

No correlation was observed between the amount of stored acid-citrate-dextrose blood administered and magnitude of negative base excess measured in 20 patients, some in shock and some not. Extreme variability in acid-base response to multiple blood transfusion would appear to make routine bicarbonate administration unadvisable. Four of five patients receiving greater than 100 mEq of sodium bicarbonate intraoperatively had postoperative arterial pH of greater than 7.48. Only two of 11 patients who received less than 100 mEq of sodium bicarbonate intraoperatively had postoperative arterial pH values greater than 7.48. Because of an undesirable shift of the oxygen dissociation curve to the left with an alkaline pH, it is suggested that bicarbonate therapy should be reserved for patients with severe metabolic acidosis (base excess, —7 mEq/liter or more) which can be established only by analysis of arterial blood for arterial carbon dioxide tension and pH.