GI loss: diarrhea or vomiting
1. Diarrhea: massive K+ loss from stool cause hypokelamia
2. Vomiting: dehydration & H+ loss => Metabolic aklalosis, HCO3-↑
=> ↑distal HCO3- delivery
因为 cation=anion Na+K+NH4+... = Cl+HCO3+...=> ↑distal Na delivery
=> 而且dehydration时RAA system ↑, 促进ENaC
=> 最后就是ENaC不断工作回收很多Na, K+就会被排出
** 所以vomiting 病人去验尿会发现是renal loss hypokalemia **
请版上大大指正
※ 引述《haowei1003 (haowei)》之铭言：
: 各位学长姐大家好 希望大家不吝指导
: 针对GI loss造成的低血钾
: uptodate的解释是The associated metabolic alkalosis and rise in plasma bicarbonate
: concentration increases the filtered bicarbonate load above its reabsorptive
: threshold. As a result, more sodium bicarbonate and water are delivered to
: the distal potassium secretory site.
: 所以我的想法如下不知有没有错误
: GI loss H+

感谢回复!!

说得不错 要分upper GI和lower GI 上排H, Cl 下排HCO3K, 另外recent or remote vomiting的结果也不同