急性胃肠黏膜损伤在危重症患者并非少见，往往与出血、感染、休克、腹腔高压（intra-abdominal hypertension，IAH）等病理过程相关。作为机体的一道重要防线，肠黏膜具有机械屏障、免疫屏障等重要生理作用，是机体内外环境的重要分水岭。肠黏膜也是缺血敏感的器官，其解剖和生理上的特点，使肠道作为休克时首先"跌倒"和最后"恢复"的器官，常常以自身黏膜损伤为代价，也是导致缺血再灌注损伤后多器官功能损伤的使动器官。但是，肠屏障功能在临床判断与目标指导性治疗上与其他器官功能障碍的治疗策略相比却明显不足。基于病理、生理特点认识严重疾病状态下的肠黏膜损伤，将有助于更好的理解和维护肠黏膜屏障的解剖与功能的完整性。

Acute gut injury is a common clinical condition in critically ill patients. It is often related to severe hemorrhage, sepsis, shock and IAH. Gut plays an important role in the development of subsequent damage to organs. Gastrointestinal mucosa is a first-line barrier between internal and external environment of the human body, and it primarily fails at the expense of mucosal damage during resuscitation. Better understanding of underlying pathophysiological processes in the development of shock, intestinal mucosal damage and multiple organ dysfunction will contribute to the optimal management of shock and maintain the function of the gut barrier.