Ceppa Eugene P, Fuh Katherine C, Bulkley Gregory B
Department of Surgery, The Johns Hopkins Hospital, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21287-4685, USA.
Curr Opin Crit Care. 2003 Apr;9(2):127-32. doi: 10.1097/00075198-200304000-00008.
The mesenteric hemodynamic response to circulatory shock is substantial and asymmetrical; the vasoconstrictive response disproportionately affects the mesenteric organs. The cardiac output is sustained partially, at no cost in nutrient flow to the mesenteric organs, by vasoconstriction of the mesenteric veins, resulting in the "autotransfusion" of up to 30% of the circulating blood volume into the systemic circulation.
Hemorrhagic or cardiogenic shock also results in decreased perfusion pressure, prompting selective vasoconstriction of the mesenteric arterioles to maintain perfusion pressure of the vital organs, here at the selective expense of the mesenteric organs. Septic shock may be associated with increased or decreased mesenteric blood flow but is characterized by increased oxygen consumption, exceeding the capability of mesenteric oxygen delivery.
The response to any of these conditions can, variably and unpredictably, cause hemorrhagic gastric stress erosions, nonocclusive mesenteric ischemia of the small bowel, ischemic colitis, ischemic hepatitis, acalculous cholecystitis, and/or ischemic pancreatitis. Injury to the mesenteric organs can also initiate the systemic inflammatory response syndrome and, consequently, multiple organ failure.
肠系膜对循环性休克的血流动力学反应显著且不对称；血管收缩反应对肠系膜器官的影响不成比例。通过肠系膜静脉的血管收缩，心输出量部分得以维持，而不会以营养物质流向肠系膜器官为代价，从而导致高达30%的循环血容量“自身输血”进入体循环。
失血性或心源性休克也会导致灌注压降低，促使肠系膜小动脉选择性血管收缩以维持重要器官的灌注压，在此过程中肠系膜器官成为选择性牺牲品。感染性休克可能与肠系膜血流量增加或减少有关，但其特征是氧消耗增加，超过了肠系膜氧输送能力。
对这些情况中的任何一种的反应都可能以可变且不可预测的方式导致出血性胃应激性糜烂、小肠非闭塞性肠系膜缺血、缺血性结肠炎、缺血性肝炎、非结石性胆囊炎和/或缺血性胰腺炎。肠系膜器官的损伤还可引发全身炎症反应综合征，进而导致多器官功能衰竭。
