Serum Anion Gap
Top Cited Papers
Open Access
- 1 January 2007
- journal article
- review article
- Published by Ovid Technologies (Wolters Kluwer Health) in Clinical Journal of the American Society of Nephrology
- Vol. 2 (1), 162-174
- https://doi.org/10.2215/cjn.03020906
Abstract
The serum anion gap, calculated from the electrolytes measured in the chemical laboratory, is defined as the sum of serum chloride and bicarbonate concentrations subtracted from the serum sodium concentration. This entity is used in the detection and analysis of acid-base disorders, assessment of quality control in the chemical laboratory, and detection of such disorders as multiple myeloma, bromide intoxication, and lithium intoxication. The normal value can vary widely, reflecting both differences in the methods that are used to measure its constituents and substantial interindividual variability. Low values most commonly indicate laboratory error or hypoalbuminemia but can denote the presence of a paraproteinemia or intoxication with lithium, bromide, or iodide. Elevated values most commonly indicate metabolic acidosis but can reflect laboratory error, metabolic alkalosis, hyperphosphatemia, or paraproteinemia. Metabolic acidosis can be divided into high anion and normal anion gap varieties, which can be present alone or concurrently. A presumed 1:1 stoichiometry between change in the serum anion gap (ΔAG) and change in the serum bicarbonate concentration (ΔHCO3−) has been used to uncover the concurrence of mixed metabolic acid-base disorders in patients with high anion gap acidosis. However, recent studies indicate variability in the ΔAG/ΔHCO3− in this disorder. This observation undercuts the ability to use this ratio alone to detect complex acid-base disorders, thus emphasizing the need to consider additional information to obtain the appropriate diagnosis. Despite these caveats, calculation of the serum anion gap remains an inexpensive and effective tool that aids detection of various acid-base disorders, hematologic malignancies, and intoxications.Keywords
This publication has 77 references indexed in Scilit:
- Effect of Hypercalcemia on the Anion GapNephron, 1990
- Plasma Acid-Base Patterns in Diabetic KetoacidosisThe New England Journal of Medicine, 1982
- Spurious Increases in the Anion Gap Due to Exposure of Serum to AirThe New England Journal of Medicine, 1982
- Diagnostic Importance of an Increased Serum Anion GapThe New England Journal of Medicine, 1980
- Increased Anion Gap in Metabolic AlkalosisThe New England Journal of Medicine, 1979
- Decreased Anion Gap in Diffuse Polyclonal HypergammaglobulinemiaThe New England Journal of Medicine, 1978
- The Anion GapThe New England Journal of Medicine, 1977
- Natural History of Lactic Acidosis after Grand-Mal SeizuresThe New England Journal of Medicine, 1977
- Value of Anion-Gap Determination in Multiple MyelomaThe New England Journal of Medicine, 1977
- CLINICAL USE OF THE ANION GAPMedicine, 1977