第三节肠内营养制剂.docVIP

第三节 肠内营养制剂 　　肠内营养的有效实施有赖于营养医师充分了解肠内营养制剂的类别、组成、特性、制备及评价等，并充分利用现代的输液系统（包括输液泵、导管、输液袋和电脑自动混合器等），使不能或不愿正常摄食的病人的营养状态得以改善。　　 一、 肠内营养制剂的分类　　按照氮的来源，可将肠内营养制剂分为非要素制剂（non-elemental diet）、要素制剂（elemental diet）及组件制剂（modular diet）三大类。　　 （一）非要素制剂　　非要素制剂，也称多聚体膳（polymeric formulas），以未加工蛋白（intact protein）或水解蛋白（hydrolyzed protein）为氮源。其中以未加工蛋白为氮源的包括混合奶和匀浆制剂。以水解蛋白为氮源的非要素制剂也称半要素膳（semi-elemental diet）。非要素制剂的渗透压接近等渗（300～450mOsm/L），口感较好，适合口服，亦可管饲。具有使用方便，耐受性强等优点。适用于胃肠道功能较好的病人。　　Semi-elemental feeds contain hydrolyzed protein as their nitrogen source and are differentiated from intact protein feeds (protein that has not been hydrolyzed) and elemental feeds (free amino acids as the sole source of nitrogen).　　1. 混合奶（milk based diet） 包括普通混合奶和高能量高蛋白混合奶两种。以全脂乳（粉）、脱脂乳（粉）、鸡蛋做为主要氮源。　　2. 匀浆制剂（blenderized diet） 也称匀浆膳。包括商品匀浆制剂和自制匀浆制剂两类。以全脂乳（乳）、脱脂乳（粉）、鸡蛋、各种肉类做为主要氮源。　　3. 以水解蛋白为氮源的非要素制剂 包括含乳糖类和不含乳糖类。　　(1)含乳糖类：以酪蛋白为主要氮源，含有乳糖。　　(2)不含乳糖类：以可溶性酪蛋白盐、大豆分离蛋白或鸡蛋清固体为主要氮源。适用于乳糖不耐受病人。　　Products differ in the source of protein and in the degree of digestion required (Table 9.3.1). The choice of a product depends on the condition of the gut and the expected degree of digestion required, as well as the cost. Product with intact nutrients (blenderized) and milk based products are the least expensive and meet nutritional needs adequately. The largest and most frequently prescribed categories of products are the lactose-free products aimed at preventing lactose-associated diarrhea. Hydrolyzed proteins are used when normal digestive enzymes are not present because of disease or when the absorptive surface of the intestine is altered in conditions such as pancreatitis or malabsorption. Table 9.3.1 Class of nutrition products by protein source and degree of digestion Class Protein source Degree of digestion required Intact nutrients Pureed beef and calcium casemate Requires normal pancreatic enzymes Milk-based Skin or powdered milk, casemate Requires normal pancreatic enzymes Lactose-free Soybean, casemates,