结肠假性梗阻患者主动钾分泌被激活:分泌型腹泻的一种新的发病机制

作     者：Van Dinter Jr. T.G Fuerst F.C Richardson C.T. J.S. Fordtran 陈云茹 

作者机构：Baylor University Medical Center 3500 Gaston Avenue Dallas TX 75246 United StatesDr. 

出 版 物：《世界核心医学期刊文摘（胃肠病学分册）》 (Core Journals in Gastroenterology)

年 卷 期：2006年第2卷第4期

页      面：22-23页

学科分类：1002[医学-临床医学] 100210[医学-外科学(含：普外、骨外、泌尿外、胸心外、神外、整形、烧伤、野战外)] 10[医学] 

主　　题：结肠假性梗阻 发病机制 分泌异常 钾离子浓度 直肠乙状结肠 腹泻患者 低钾血症 排出物 结肠扩张 结 

摘      要：Background &Aims: Secretory diarrhea is caused by inhibition of intestinal active sodium absorption and stimulation of active chloride secretion. The resulting increase in fecal sodium salts causes an isotonic increase in fecal water output. Abnormalities in potassium transport are not known to be a cause of secretory diarrhea. The aim of our report is to describe a patient with secretory diarrhea that was mediated by excess intestinal secretion of potassium. Methods: A 78-yearold woman developed colonic pseudo-obstruction, complicated by severe dia rrhea and hypokalemia. Her stools were collected quantitatively on 11 occasions and analyzed for electrolyte concentrations. Rectosigmoid potential difference w as measured. Results: The diarrheal fluid had a very high potassium concentratio n (130-170 mEq/L) and a very low sodium concentration (4-15 mEq/L). Stool pota ssium losses were as high as 256 mEq/day (normal, 9 mEq/day), and fecal sodium l osses were never higher than 13 mEq/day. Potential difference between colonic lu men and a peripheral reference electrode was -14 mV (lumen side negative). Conc lusions: Fecal potassium salts were the exclusive driving force for severe secre tory diarrhea in a patient with colonic pseudo-obstruction. The high fecal outp ut of potassium was due to stimulation of active colonic potassium secretion, po ssibly because of changes in autonomic nervous system activity and distention of the colon in association with colonic pseudo-obstruction. The extremely low fe cal excretion of sodium indicates that active sodium absorption was not inhibite d. This case study reveals an ion transport mechanism of secretory diarrhea that has not been previously appreciated.