Refers to the difference between the concentration of serum sodium and the total of serum anions chloride and bicarbonate (Anion gap=Na-Cl+HCO3).
The anion gap represents the difference between unmeasured cations and anions in the plasma.
Normal range is 7-13 mEq/L.
Calculated as [Na+]-[Cl-]-[HCo3-]
Major unmeasured cations or calcium, magnesium, gamma globulin’s, and potassium.
Major unmeasured cations are albumin, phosphate, sulfate, lactate, and other organic ions.
The normal anion gap is 12 +/- 4 mEq per liter
A normal gap characterized by a lowered bicarbonate concentration, which in the presence of a normal sodium concentration is counterbalanced by an equivalent increase in plasma chloride concentration-hypercholoremic metabolic acidosis.
A true ion gap does not exist in vivo, because the sum of the positive and negative ion charges in plasma must be equal.
Increased anion gap associated with renal failure, ketoacidosis, lactic acidosis and ingestion of various toxins.
A normal gap characterized by a lowered bicarbonate concentration , which in the presence of a normal sodium concentration is counterbalanced by an equivalent increase in plasma chloride concentration-hypercholoremic metabolic acidosis.