{"id":19050,"date":"2020-08-25T05:23:49","date_gmt":"2020-08-24T21:23:49","guid":{"rendered":"http:\/\/csccm.org.cn\/?p=19050"},"modified":"2020-08-29T07:05:07","modified_gmt":"2020-08-28T23:05:07","slug":"deranged-physiology%e6%96%87%e7%ab%a0%ef%bc%9a%e5%b0%bf%e7%94%b5%e8%a7%a3%e8%b4%a8%e4%b8%8e%e5%b0%bf%e9%98%b4%e7%a6%bb%e5%ad%90%e9%97%b4%e9%9a%99","status":"publish","type":"post","link":"https:\/\/csccm.org.cn\/?p=19050","title":{"rendered":"[Deranged Physiology\u6587\u7ae0]\uff1a\u5c3f\u7535\u89e3\u8d28\u4e0e\u5c3f\u9634\u79bb\u5b50\u95f4\u9699"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">Urinary electrolytes and the urinary anion gap<\/h1>\n\n\n\n<h3 class=\"wp-block-heading\">Urinary anion gap<\/h3>\n\n\n\n<p>The urinary anion gap is extensively explored in&nbsp;<a href=\"https:\/\/derangedphysiology.com\/main\/node\/2008\">the chapter on the diagnosis of renal tubular acidosis.&nbsp;<\/a>Its role in the SAQs has been limited to the diagnosis of renal tubular acidosis (i.e where it is used to discriminate between renal and non-renal causes of a normal anion gap acidosis, such as in&nbsp;<a href=\"http:\/\/www.derangedphysiology.com\/main\/cicm-fellowship-exam\/past-papers\/2013-paper-2-saqs\/question-34\">Question 3.4&nbsp;&nbsp;<\/a>from the second paperof 2013).<\/p>\n\n\n\n<p>In brief:<\/p>\n\n\n\n<ul><li>Urinary anion gap is the difference between the excreted chloride and the excreted cations.<\/li><li>The formula is (Na<sup>+<\/sup>&nbsp;+ K<sup>+<\/sup>) - Cl<sup>-<\/sup><\/li><li>If there is more chloride than cations, i.e. a \"negative\" urinary anion gap, it means another cation - namely ammonium - is being excreted<\/li><li>Increased ammonium excretion is the appropriate renal reaction to acidosis<\/li><li>Thus, a negative urinary anion gap demonstrates that the cause of a normal anion gap metabolic acidosis is not related to renal tubular function. In other words, its not an RTA, its diarrhoea.<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Urinary electrolytes<\/h3>\n\n\n\n<p>As for the urinary electrolytes...Why would you order any of those?<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td>Indication<\/td><td>Electrolyte<\/td><td>Meaning of results<\/td><\/tr><tr><td>Oliguria<\/td><td>Na+<\/td><td>Na+\u00a0&lt; 20mmol\/L: appropriate conservation of sodium in the context of hypovolemia<br \/>Na+\u00a0>20mmol\/L: renal failure, eg. ATN<\/td><\/tr><tr><td><\/td><\/tr><tr><td>Hyponatremia<\/td><td>Na+<\/td><td>Na+\u00a0&lt; 20mmol\/L: appropriate conservation of sodium in the context of hyponatremia<br \/>Na+\u00a0>20mmol\/L: renal salt wasting, eg:<br \/>- cerebral salt wasting or SIADH<br \/>- adrenal insufficiency<br \/>- diuretic use<br \/>- osmotic diuresis eg. mannitol or glucose<\/td><\/tr><tr><td>\u3001<\/td><\/tr><tr><td>Normal anion gap metabolic acidosis<\/td><td><a href=\"http:\/\/www.derangedphysiology.com\/main\/node\/2008\">Urinary anion gap<\/a><\/td><td><strong>Positive:\u00a0<\/strong>renal causes of NAGMA<br \/><strong>Normal or Negative:<\/strong>\u00a0gastrointestinal causes of NAGMA<\/td><\/tr><tr><td><\/td><\/tr><tr><td><a href=\"https:\/\/derangedphysiology.com\/main\/node\/2048\">Metabolic alkalosis<\/a><\/td><td>Cl-<\/td><td>0-10: appropriate renal chloride conservation<br \/>- gastric chloride losses<br \/>- diuretic therapy (between doses)<br \/>- post hypercapnea alkalosis<br \/>>20: inappropriate renal chloride loss<br \/>- corticosteroid excess<br \/>- hypertension<br \/>- hyperaldosteronism\u00a0<\/td><\/tr><tr><td><\/td><\/tr><tr><td><a href=\"https:\/\/derangedphysiology.com\/main\/node\/2192\">Hypokalemia<\/a><\/td><td>K+<\/td><td>Low urinary potassium: &lt;2mmol\/L\uff1aDiarrhoea, Laxative abuse, Insulin therapy, Bicarbonate therapy, <a href=\"http:\/\/www.sciencedirect.com\/science\/article\/pii\/0022510X94900493\">Periodic hypokalemic paralysis<\/a><br \/>High urinary potassium: >5mmol\/L:<br \/>Renal tubular acidosis (Type 1 or 2), Hyperaldosteronism, Upper gastrointestinal losses, Corticosteroid excess<\/td><\/tr><tr><td><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Urinary electrolytes and the urinary anion gap Urinary  [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[13,14],"tags":[],"_links":{"self":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/19050"}],"collection":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=19050"}],"version-history":[{"count":4,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/19050\/revisions"}],"predecessor-version":[{"id":19052,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/19050\/revisions\/19052"}],"wp:attachment":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=19050"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=19050"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=19050"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}