Serum Anion Gap
Standard & Albumin-Corrected Metabolic HUD
Enter electrolytes and albumin
to calculate Corrected Gap
Clinical Utility of the Corrected Anion Gap
The Anion Gap (AG) is a critical tool for narrowing the differential diagnosis of metabolic acidosis. However, in the ICU, standard AG can be misleading. Since albumin is the primary unmeasured anion, low levels (hypoalbuminemia) will falsely lower the anion gap, potentially masking an underlying acidosis.
Frequently Asked Questions
How do I interpret a High Anion Gap (HAGMA)?
A HAGMA indicates the addition of fixed acids to the blood. Common causes include Diabetic Ketoacidosis (DKA), Lactic Acidosis (Sepsis/Shock), or toxic ingestions (Salicylates/Glycols). Use the MUDPYLES mnemonic for a systematic check.
What is the "Normal" Anion Gap?
Historically, 8-12 mEq/L is considered normal. However, you must always look at the patient's baseline Albumin. For every 1g/dL drop in Albumin, the "normal" AG drops by 2.5 mEq/L.
Clinical Bibliography
- 1. Figge J, et al. Anion gap and hypoalbuminemia. Crit Care Med. 1998.
- 2. Oh's Intensive Care Manual. 8th Edition.
CLINICAL RESOURCE