A calculation based on measurements in serum or plasma to assist with determining the cause of a metabolic acidosis of unknown origin.
Anion Gap = Sodium + Potassium – (chloride + bicarbonate) (all measurements in mmol/L)
Note: variability in result due to uncertainty in measurements approx. +/- 5 mmol/L.
For more information, see the SydPath Information Page
Reference Interval : 10 - 18 mmol/L Interpretation The more common causes of a raised anion gap are as follows: • Elevated serum lactate • Ketoacidosis (raised beta-hydroxybutyrate and acetoacetate) • Reduced kidney function • Toxins (e.g. ethanol, methanol, ethylene glycol, salicylates)