Anion gap: Difference between revisions
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==Elevated Anion Gap== | ==Elevated Anion Gap== | ||
=== | ===Differential Diagnosis=== | ||
MUDPILES | MUDPILES | ||
*M - [[Methanol]] | *M - [[Methanol]] | ||
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*Starvation/[[Alcoholic ketoacidosis|ETOH ketoacidosis]] | *Starvation/[[Alcoholic ketoacidosis|ETOH ketoacidosis]] | ||
*[[Carbon monoxide toxicity| Carbon Monoxide (CO)]], [[Cyanide|CN poisoning]] (incr. lactate) | *[[Carbon monoxide toxicity| Carbon Monoxide (CO)]], [[Cyanide|CN poisoning]] (incr. lactate) | ||
* | *Toluene | ||
* | *Chronic [[acetaminophen]] use | ||
==Low Anion Gap== | ==Low Anion Gap== | ||
=== | ===Differential Diagnosis=== | ||
*Lab error | *Lab error | ||
*Decreased "unmeasured" anions | *Decreased "unmeasured" anions | ||
** | **Hypoalbuminemia | ||
*Increased "unmeasured" cations | *Increased "unmeasured" cations | ||
**[[Hyperkalemia]] | **[[Hyperkalemia]] | ||
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**[[Lithium Toxicity]] | **[[Lithium Toxicity]] | ||
*Increased cationic paraprotein | *Increased cationic paraprotein | ||
* | *[Multiple myeloma | ||
**Polyclonal IgG gammopathy | **Polyclonal IgG gammopathy | ||
*Pseudo | *Pseudo | ||
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**Marked hyperlipidemia | **Marked hyperlipidemia | ||
***Leads to overestimation of plasma Cl conc) | ***Leads to overestimation of plasma Cl conc) | ||
**Bromide intoxication (e.g. for myasthenia gravis and some herbal medications) | **Bromide intoxication (e.g. for [[myasthenia gravis]] and some herbal medications) | ||
***Machine mistakenly reads Br as Cl | ***Machine mistakenly reads Br as Cl | ||
*AG falls by 2.5 meq/L for every 1 g/dL reduction in albumin concentration | *AG falls by 2.5 meq/L for every 1 g/dL reduction in albumin concentration | ||
==See Also== | ==See Also== | ||
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==Sources== | ==Sources== | ||
<references/> | <references/> | ||
[[Category:FEN]] | [[Category:FEN]] | ||
[[Category:Tox]] | [[Category:Tox]] | ||
Revision as of 18:32, 14 May 2015
Background
AG = Na - (Cl + HCO3)
Normal Anion Gap = 12+/-4 (8-16)
Cutoffs for "normal" Anion Gap are laboratory and equipment specific. Newer technology and equipment have been shown to measure "low" AG in otherwise normal, healthy people.[1][2]
Elevated Anion Gap
Differential Diagnosis
MUDPILES
- M - Methanol
- U - Uremia
- D - DKA
- P - Paraldehyde
- I - Iron, INH
- L - Lactic acidosis
- E - Ethylene glycol
- S - Salicylates
Also:
- Starvation/ETOH ketoacidosis
- Carbon Monoxide (CO), CN poisoning (incr. lactate)
- Toluene
- Chronic acetaminophen use
Low Anion Gap
Differential Diagnosis
- Lab error
- Decreased "unmeasured" anions
- Hypoalbuminemia
- Increased "unmeasured" cations
- Increased cationic paraprotein
- [Multiple myeloma
- Polyclonal IgG gammopathy
- Pseudo
- Severe Hypernatremia (>170 meq/L)
- True conc of Na is underestimated
- Marked hyperlipidemia
- Leads to overestimation of plasma Cl conc)
- Bromide intoxication (e.g. for myasthenia gravis and some herbal medications)
- Machine mistakenly reads Br as Cl
- Severe Hypernatremia (>170 meq/L)
- AG falls by 2.5 meq/L for every 1 g/dL reduction in albumin concentration
See Also
Anion Gap and Osmolar Gap (High)