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
因為 cation=anion Na+K+NH4+... = Cl+HCO3+...=> ↑distal Na delivery
=> 而且dehydration時RAA system ↑, 促進ENaC
=> 最後就是ENaC不斷工作回收很多Na, K+就會被排出
** 所以vomiting 病人去驗尿會發現是renal loss hypokalemia **
請版上大大指正
※ 引述《haowei1003 (haowei)》之銘言：
: 各位學長姐大家好 希望大家不吝指導
: 針對GI loss造成的低血鉀
: uptodate的解釋是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沒有錯誤
: GI loss H+