Department of Anesthesiology and Intensive Care Medicine, Division of Anesthesiology for Cardiovascular Surgery and Intensive Care Medicine, Medical University of Graz, Graz, Austria.
Department of Anesthesiology and Intensive Care Medicine, Division of Anesthesiology for Cardiovascular Surgery and Intensive Care Medicine, Medical University of Graz, Graz, Austria.
Lancet Gastroenterol Hepatol. 2018 Apr;3(4):281-287. doi: 10.1016/S2468-1253(18)30036-0. Epub 2018 Mar 7.
Nutritional management is a cornerstone of therapy for patients who are critically ill. Data show that enteral nutrition is better than parenteral nutrition with regard to the morbidity of critcally ill patients, especially for infectious complications. These findings suggest that feeding patients enterally has other beneficial effects besides delivering nutrients. In the absence of enteral nutrition, the mucosal architecture changes distinctly, leading to an impairment in function of the gastrointestinal barrier. This impairment facilitates the migration of bacteria from the intestinal lumen into the submucosal tissue and triggers epithelial inflammation. Consequently, proinflammatory and anti-inflammatory factors are imbalanced, leading to further degradation of gastrointestinal mucosal resistance. The enteral stimulus is also important to maintain physiological interaction of commensal bacteria with enteric immune cells. The absence of enteral nutrition induces deregulation of receptors that modulate the immunological response to commensal bacteria and pathogens-an important factor that initiates intestinal inflammation. Additionally, without enteral nutrients, the gastrointestinal mucosa atrophies because epithelial cells absorb nutrients directly from the gastrointestinal tract to meet their nutritional requirements. All these negative effects of absent enteral nutrition can be explained by a distinct change in cellular signalling pathways. Studies show that the physiological stimulus of enteral nutrition is crucial to maintain gastrointestinal functions such as barrier, immunological, and resorptive function. Enteral nutrients are important to maintain intact gastrointestinal motility since the nutrients stimulate the secretion of motility-regulating gastrointestinal hormones.
营养管理是危重症患者治疗的基石。有数据表明，与肠外营养相比，肠内营养可降低危重症患者的发病率，尤其是感染性并发症。这些发现提示，肠内喂养除了提供营养物质外，还有其他有益作用。在没有肠内营养的情况下，黏膜结构会发生明显改变，导致胃肠道屏障功能受损。这种损伤促进了细菌从肠腔向黏膜下层组织的迁移，并引发上皮炎症。因此，促炎和抗炎因子失衡，导致胃肠道黏膜抵抗进一步降解。肠内刺激对于维持共生菌与肠免疫细胞的生理相互作用也很重要。缺乏肠内营养会导致调节对共生菌和病原体免疫反应的受体失调——这是引发肠道炎症的一个重要因素。此外，由于上皮细胞直接从胃肠道吸收营养物质来满足其营养需求，没有肠内营养时，胃肠道黏膜会萎缩。所有这些没有肠内营养的负面影响都可以通过细胞信号通路的明显改变来解释。研究表明，肠内营养的生理刺激对于维持胃肠道功能（如屏障、免疫和吸收功能）至关重要。肠内营养对于维持完整的胃肠道动力很重要，因为营养物质会刺激调节胃肠道动力的激素分泌。
