Chapman Marianne J, Nguyen Nam Q, Fraser Robert J L
Intensive Care Unit, Royal Adelaide Hospital, Adelaide, Australia.
Curr Opin Crit Care. 2007 Apr;13(2):187-94. doi: 10.1097/MCC.0b013e3280523a88.
Enteral nutrition is frequently unsuccessful in the critically ill due to gastrointestinal dysfunction. Current treatment strategies are often disappointing. In this article upper gastrointestinal function in health together with abnormalities seen during critical illness are reviewed, and potential therapeutic options summarized.
Reflux oesophagitis occurs frequently due to reduced or absent lower oesophageal sphincter tone. In the stomach a number of motor patterns contribute to slow gastric emptying. The fundus has reduced compliance, there are less frequent contractions in both the proximal and distal stomach, isolated pyloric activity is increased and the organization of duodenal motor activity is abnormal. In response to nutrients, enterogastric feedback is enhanced, fundic relaxation and subsequent recovery is delayed, antral motility is further reduced and localized pyloric contractions stimulated. Elevated concentrations of hormones such as cholecystokinin and peptide YY are potential mediators for these phenomena. Rapid tachyphylaxis occurs with the commonly used prokinetics, metoclopramide and erythromycin, and novel agents are under investigation. Independent of gastric emptying, nutrient absorption is reduced.
There has been considerable progress in understanding the pathogenesis of mechanisms causing feed intolerance in critical illness, but this is yet to be translated into therapeutic benefit.
由于胃肠功能障碍，肠内营养在危重症患者中常常难以成功实施。目前的治疗策略往往不尽人意。本文回顾了健康状态下上消化道的功能以及危重症期间出现的异常情况，并总结了潜在的治疗选择。
由于食管下括约肌张力降低或消失，反流性食管炎频繁发生。在胃中，多种运动模式导致胃排空缓慢。胃底顺应性降低，胃近端和远端的收缩频率减少，幽门单独活动增加，十二指肠运动活动的组织异常。对营养物质的反应中，肠胃反馈增强，胃底松弛及随后的恢复延迟，胃窦蠕动进一步减少，局部幽门收缩受到刺激。胆囊收缩素和肽YY等激素浓度升高是这些现象的潜在介质。常用的促动力药甲氧氯普胺和红霉素会迅速产生快速耐受性，新型药物正在研究中。与胃排空无关，营养物质吸收减少。
在理解危重症中导致喂养不耐受的机制的发病机制方面已经取得了相当大的进展，但这尚未转化为治疗益处。
