ANION GAP

• Anion Gap is used to differentiate the causes of metabolic acidosis.
• High anion gap with metabolic acidosis is assumed to have come from an acid that does not contain Cl as an anion (phosphates, sulfates, lactate, keto acids, salicylate, metabolites of ethylene glycol)
• Metabolic acidosis with a normal anion gap = due to an increase in plasma Cl concentration

Simple AG
AG = (Na + K) - (Cl + Bicarb)

Source: UCD Emergency & Critical Care group.