Intravenous glucose, aminoacids, and fat in the postoperative period. A controlled evaluation of each substrate.

The metabolic effects of hypocaloric (2-51 MJ), equicalorific quantities of intravenous glucose, crystalline aminoacids, and soyabean emulsion were comapred with those of fasting in 4 groups of male patients (closely matched for age, weight, and fat-free mass) on the day of vagotomy and pylorplasty and on the fast 3 postoperative day. Patients given glucose alone excreted less nitrogen than the fasting patients but nitrogen sparing was greatest in the group given aminoacids alone. There was no evidence of any nitrogen sparing when intravenous fat was the source of energy. There was no difference in blood glucose, free fatty acids, and insulin concentrations among the groups. Ketone-body concentrations rose in the fasting and fat-fed groups but remained low in the groups who received glucose or aminoacids. This study indicates that, in the short term, the increased preservation of protein achieved by the infusion of aminoacids compared with that produced by the traditional infusion of glucose does not warrant the extra cost involved.