Anion Gap The difference between [Nat] and the sum of [HCO3]and [cl]. a[Na+]-([Hc03]+[c]) 140-(24+105)=11 norma|=12±2 Clinicians use the anion gap to identify the cause of metabolic acidosisAnion Gap ◼ The difference between [Na+] and the sum of [HC03 -] and [Cl-]. ◼ [Na+] – ([HC03 -] + [Cl-]) = ◼ 140 - (24 + 105) = 11 ◼ Normal = 12 ± 2 ◼ Clinicians use the anion gap to identify the cause of metabolic acidosis