Changes in plasma lactate, phosphate and uric acid during postoperative carbohydrate infusion.

Eighteen patients undergoing elective abdominal surgery had pre- and postoperative carbohydrate infusion tests with glucose, fructose or sorbitol. All three substrates produced significant hyperlactataemia postoperatively, the elevations of plasma lactate with fructose and sorbitol infusion being significantly greater than with glucose. Plasma uric acid was unchanged but there were moderate falls in plasma phosphate postoperatively. Intravenous nutritional regimens containing fructose and sorbitol may potentiate the development of harmful metabolic acidoses in 'at risk' patients and should always be used cautiously. Glucose is the carbohydrate calorie source of choice.