Metabolic acidosis is a common clinical disturbance due to increased plasma acidity caused by a primary decrease in serum HCO3- concentration. It is classified as normal or high anion gap metabolic acidosis. High anion gap metabolic acidosis can result from either a decrease in unmeasured cations (K+, Ca2+, Mg2+) or an increase in unmeasured anions (PO43-, albumin). However, other anions such as lactic acid or keto acids may cause this acid-base disorder. It can also result from renal failure and intoxication (salicylate, methanol, ethylene glycol), or more rarely, from massive rhabdomyolysis and pyroglutamic (5-oxoproline) acidemia. Acidemia due to pyroglutamic acid should be considered when no other aetiology is found. High anion gap meta...