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Old 02-13-2014
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Question Non-Anion Gap Metabolic Acidosis

Hey,

I've been trying to get my head around why loss of HCO3 from diarrhoea or type 2 RTA leads to a non-anion gap acidosis, when the equation to calculate anion gap is:

[Na + K] - [Cl + HCO3]

I know that I've missed out a bit of physiology knowledge that would make it make sense but at the moment I'm just wondering that shouldn't a lower level of bicarb lead to a bigger number of the anion gap?

Thanks for any help.
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Old 02-13-2014
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u have compensatory increase in Cl absorption which makes no change in anion gap
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Ahh I see. Thanks.
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Quote:
Originally Posted by MedicalExaminer View Post
u have compensatory increase in Cl absorption which makes no change in anion gap
And I was then wondering, why is it that there is an increased anion gap when there is an excess of H+ which is buffered by the HCO3? Is there no compensatory increase in Cl absorption when HCO3 is used up that way?

Thanks again.
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Quote:
Originally Posted by Skitzo View Post
And I was then wondering, why is it that there is an increased anion gap when there is an excess of H+ which is buffered by the HCO3? Is there no compensatory increase in Cl absorption when HCO3 is used up that way?

Thanks again.
when acid increases in body (for example lactic acid)
excess H+ is buffered by HCO3 and negative charge of lost bicarb is replaced by conjugate base form of that acid (lactate) instead of Cl to achieve electrical neutrality
this creates increased anion gap
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