Anion Gap
Info
Na (mEq/L)
Cl (mEq/L)
HCO3 (mEq/L)
R e s u l t s
Anion Gap in mEq/L
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Anion Gap

The serum anion gap is mainly used to assess acid-base disorders.

Provides difference between the concentration of unmeasured anions (UA) and unmeasured cations (UC) in serum

Normal Range: 12 ± 4 mEq/L

Gap acidoses: salicylates, uremic, methanol, paraldehyde, lactic, ethylene glycol, ketoacidosis

Nongapacidoses: carbonic anhydrase inhibitor, Renal tubular acidosis (RTA), ureteral diversions, diarrhea/GI HCO3 losses.

Formula:

  • Anion Gap in mEq/L = [Na] - ([Cl] + [HCO3])

Data the user will need:

  • Serum Na (mEq/L)
  • Serum Cl (mEq/L)
  • Serum HCO3 (mEq/L)

Result will be displayed as Anion gap in mEq/L

Interpretation:

User need to enter the value of above mentioned electrolytes, which is used in the formula given below

  • Anion Gap in mEq/L = [Na] - ([Cl] + [HCO3])

References:

  1. Kraut JA, Madias NE. Serum anion gap: its uses and limitations in clinical medicine. Clin J Am Soc Nephrol . 2007 Jan;2(1):162-74. Epub 2006 Dec 6.
  2. Lolekha PH, Vanavanan S, Lolekha S. Update on value of the anion gap in clinical diagnosis and laboratory evaluation. Clin Chim Acta . 2001;307(1-2):33-6.