Home >> Study >> ForumTopic: Urinary anion gap
You need to be logged in to post messages.
| Author: | Message |
| superbdoc Total Posts: 273 | Posted: Wed Oct 08, 2008 03:11 pm Urinary anion gap (UAG) is an indicator of elimination of NH4+. (AI 2002) |
| superbdoc Total Posts: 273 | Posted: Wed Oct 08, 2008 03:14 pm Explanation: Ammonium is positively charged so a rise in its urinary concentration (ie increased unmeasured cations) will cause a fall in UAG as can be appreciated by inspection of the formula Urinary Anion Gap = ( UA - UC ) = [Na+]+ [K+] - [Cl-] Key Fact: The urinary anion gap can help to differentiate between GIT and renal causes of a hyperchloraemic metabolic acidosis. * A negative UAG suggests GIT loss of bicarbonate (eg Diarrhoea) * A positive UAG suggests impaired renal distal acidification (ie Renal tubular acidosis). As a memory aid, remember ‘neGUTive’ - negative UAG in bowel causes |