Maltose as an energy substrate during surgery: Comparison of maltose with glucose

Abstract

To evaluate the usefulness of maltose as an energy substrate to be administered during surgery, five per cent maltose in lactated Ringer's solution and five per cent glucose in lactated Ringer's solution were administered to 10 cases each, at a rate of 5 ml.kg -~ hour (0.25 g'kg -t hour as sugar) for two hours from the start of oral surgery, and their metabolic effects were compared.The maltose group showed a smaller increase in blood sugar level than the glucose group immediately after the completion of infusion. The mean plasma concentration of maltose reached a maximum of 121.6 mg/dl, and it remained at 12.3 mg/dl at four hours, indicating that the retention time of maltose in blood was longer than that of glucose. The mean recovery of sugar from four-hour urine samples was 3.26 per cent in the maltose group and 0.06 per cent in the glucose group respectively, showing greater urinary excretion by the maltose group.Plasma insulin was elevated less after maltose than after glucose infusion. The elevation following maltose infusion was considered not to be due to the administration of maltose per se, but to glucose produced from the maltose in the body.The anti-ketogenie effect of maltose was comparable to and tended to last longer than that of glucose.From overall assessment it was concluded that maltose exerts essentially the same metabolic effects as glucose when used under these conditions. KEY WORDS: METABOLISM, energy substrate, maltose, glucose.THE PATIENT is often in a starved state when exposed to the stress caused by surgical operations or other therapy. The stress usually accelerates catabolic responses in the body. However, in such a state there is little sugar in the body usable as an energy source (mainly glycogen) and hence, once it is consumed, muscle protein begins to be converted to glucose by gluconeogenesis and fat tissues are converted to free fatty acids. As a consequence, these are used as a main energy source. The use of protein and fat wastes muscle tissue and induces increases in ketone body and free fatty acid concentrations. To prevent these phenomena, it is necessary to supply sugar as an energy source. Moffitt, etal. 1 reported that glucose given during abdominal surgery increased the metabolism of glucose and decreased the utilization of fat. 23 On the other hand, Young and Weser, et al. 9 demonstrated that intravenous maltose is well Kazuya Aono, M.D., Professor; Nobuko Kawachino, B.S., Kunihiko Satoh, D.D.S., Assistants; Department of Anesthesiology, Fukuoka Dental College, Fukuoka, 814-01 Japan.Can. Anaesth. Soc. J., vol. 29, no. 3, May 1982 utilized in humans. Since then, maltose has been widely used in Japan. Subsequent studies have shown that maltose does not markedly increase blood sugar level and is less insulin-dependent than glucose. A 10 per cent solution of maltose has about the same osmotic pressure as that of plasma, half of that of glucose in the same concentration, which implies that at the same osmotic pressure maltose supplies twice as many calories...