Reduced function of neutrophils during routine postoperative glucose infusion

Postoperative infusion of carbohydrate solution leads to moderate fall in the serum concentration of inorganic phosphate. The possible significance of this fall for cellular function as expressed by the neutrophils was investigated in 16 patients undergoing elective cholecystectomy. On postoperative day 2 all received 1 l 10% glucose intravenously to which in eight (randomly chosen) cases 10 mmol phosphate buffer/l had been added. Blood was sampled preoperatively and before and after the infusion. The group without phosphate supplement showed the expected significant fall in serum phosphate during the glucose infusion. The phosphate supplement prevented this fall. The hypophosphatemia was associated with significant reduction of neutrophil phagocytosis, intracellular killing, consumption of oxygen and generation of superoxide during phagocytosis. No parameter expressing neutrophil function was affected in the group with phosphate supplement. The obligatory fall in serum concentration of inorganic phosphate during postoperative carbohydrate infusion was concluded to be a cause of cellular dysfunction, the clinical importance of which is unknown.