Anion gap: Difference between revisions
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Normal Anion Gap = 12+/-4 (8-16) <br/> | Normal Anion Gap = 12+/-4 (8-16) <br/> | ||
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. | 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.<ref>Jurado RL, del Rio C, Nassar G, Navarette J, Pimentel JL Jr. "Low anion gap." South Med J. 1998;91(7):624</ref><ref>Winter SD, Pearson JR, Gabow PA, Schultz AL, Lepoff RB. "The fall of the serum anion gap." Arch Intern Med. 1990;150(2):311</ref> | ||
==Elevated Anion Gap== | ==Elevated Anion Gap== | ||
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Kaji Questions <br /> | Kaji Questions <br /> | ||
MISTRY 6/06 | MISTRY 6/06 | ||
==References== | |||
<references /> | |||
[[Category:FEN]] | [[Category:FEN]] | ||
[[Category:Tox]] | [[Category:Tox]] | ||
Revision as of 16:48, 7 February 2014
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
DDx
MUDPILES
- M - Methanol
- U - Uremia
- D - DKA
- P - Paraldehyde
- I - Iron, INH
- L - Lactic acidosis
- E - Ethylene glycol
- S - Salicylates
Also:
- Starvation/ETOH ketoacidosis
- CO, CN poisoning (incr. lactate)
Low Anion Gap
DDX
- 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)
Source
Kaji Questions
MISTRY 6/06