Plasma Anion Gap

  • Used in determining cause of metabolic acidosis

  • Difference between major cations (sodium and potassium) and major anions (chloride and bicarbonate)

= (Na+ + K+) - (Cl- + HCO3-)

  • Normal range <16 mmol

  • if greater than this then lactate, formate, oxalate formation

  • indicates quantity of added acid as mirrors fall in bicarbonate

High anion gap metabolic acidosis

  • Lactic acidosis

  • Ketoacidosis

  • Renal failure

  • Ingestion of e.g. methanol, ethanol, ethylene glycol

Normal anion gap metabolic acidosis

  • GI loss of bicarbonate

  • Renal bicarbonate loss (type 2 renal tubular acidosis)

 

[ Home ] [ Up ]