第四节 肠外营养的应用.doc

第四节 肠外营养的应用 ? 　　一、肠外营养的适应症　　An indication for parenteral nutrition can be short bowel syndrome. The most important feature of this syndrome is insufficient absorption of nutrients, indicating the need for parenteral nutritional support. Multiple organ failure, often caused by sepsis, is a condition in which several organs malfunction or do not function at all. In this situation complete or supplementary parenteral nutrition is indicated. Another indication for parenteral support consists of entero-cutaneous fistulas, especially high output fistulas, which are often located proximally in the small bowel. An adynamic ileus, another indication for parenteral support, is characterized by lack of peristalsis and passage. Patients with chronic bowel obstruction also require parenteral nutrition. Indications for parenteral feeding are listed in Box 9.4.1.　　Box 9.4.1 Indications for parenteral nutrition　　●Mucositis following chemotherapy　　●A minority of patients with inflammatory bowel disease where enteral nutrition has failed to prevent or reverse malnutrition (i.e. severe malabsorption)　　●Patients with multiorgan failure where nutritional requirements cannot be met by the enteral route alone　　●Intestinal atresia　　● Radiation enteritis　　●Motility disorders such as scleroderma or chronic idiopathic intestinal pseudoobstruction syndromes　　●Extreme short bowel syndrome of any etiology　　　　 肠外营养的基本适应症是胃肠道功能障碍或衰竭的病人。凡病人存在营养不良，或估计1周以上无法正常饮食者，都有肠外营养治疗的指征。凡是需要营养支持，但又不能或不宜接受肠内营养支持的病人均为肠外营养支持的适应症。许多外科情况，例如营养不良者的围手术期、瘫痪、大面积烧伤，炎性肠道疾病、克隆氏病或溃疡性结肠炎的急性期，重症急性胰腺炎等疾病的病程多长达1月以上，过早恢复肠内营养可能使病情加重，故应采用肠外营养，以维持机体营养需要。美国肠内肠外营养支持协会（ASPEN）提出应用肠外营养支持的准则，按疗效分为：1、疗效显著的适应症；2、肠外营养对治疗有益的中适应症；3、肠外营养支持疗效不肯定的弱适应症；肠外营养的禁忌症。　　 （一）消化系统疾病　　胃肠需要充分休息或消化吸收障碍时，需肠外营养支持。　　1. 消化道瘘 高位小肠瘘因所进食物会从瘘口排出，造成营养物质吸收障碍，而且大量消化液的丢失使病人发生脱水及电解质紊乱，加之肠瘘病人常同时伴有腹腔感染及脓肿，使机体进一步耗竭，短期内即可导致死亡。肠外营养支持不仅可以供给充足的营养，而且还可使消化道休息，大大减少消化液的分泌与丧失，提高组织愈合能力。　　2. 炎症性肠病 包括溃疡性结肠炎与克隆氏病等。肠外营养可减轻腹部不适与腹泻等症状，对于肠道炎性疾病引起生长发育停滞的儿童，在给予充分的肠外营养支持后，能够恢复