Shizgal H M, Milne C A, Spanier A H
Surgery. 1979 May;85(5):496-503.
The postoperative protein-sparing effect of intravenously administered amino acids was assessed quantitatively by measuring body composition by multiple isotope dilution. Body composition was determined in two groups of 19 patients each, before and on the fifth day following a major abdominal operation. One group of patients received all of their required fluids and electrolytes as a 5% glucose solution. The second group received an isocaloric infusion of protein as a 5% casein hydrolysate solution. The preoperative body composition of both groups was normal. On the fifth day after operation, the mean body weight had decreased by 2.6 plus or minus 0.6 kg in the glucose group and by 2.0 plus or minus 0.5 kg in the protein group. In the patients receiving glucose, this postoperative weight loss was due to a decrease in both body fat and the lean body mass. The mean body cell mass, which represents the total mass of living, functioning cells, decreased from 23.1 plus or minus 1.5 to 19.9 plus or minus 1.4 kg (P less than 0.001), while the extracellular mass increased from 24.9 plus or minus 0.9 to 27.3 plus or minus 0.9 kg (P less than 0.001). In contrast, in the patients receiving protein, the loss of body weight resulted entirely from a loss of body fat, while the body cell mass and the extracellular mass both remained normal. Therefore protein sparing was achieved by the postoperative infusion of protein.
通过多次同位素稀释法测量身体成分，对静脉输注氨基酸的术后蛋白质节省效应进行了定量评估。在两组各19例患者中，于腹部大手术后第5天及术前测定身体成分。一组患者接受全部所需液体和电解质，以5%葡萄糖溶液输注。第二组接受等热量的蛋白质输注，以5%酪蛋白水解物溶液输注。两组患者术前身体成分均正常。术后第5天，葡萄糖组平均体重下降2.6±0.6kg，蛋白质组下降2.0±0.5kg。接受葡萄糖输注的患者，术后体重减轻是由于体脂和去脂体重均减少。代表存活功能细胞总质量的平均身体细胞质量从23.1±1.5kg降至19.9±1.4kg（P<0.001），而细胞外质量从24.9±0.9kg增加至27.3±0.9kg（P<0.001）。相比之下，接受蛋白质输注的患者，体重减轻完全是由于体脂减少，而身体细胞质量和细胞外质量均保持正常。因此，术后输注蛋白质可实现蛋白质节省。
