Citric acid ingestion: A life-threatening cause of metabolic acidosis

We present a case that illustrates the acute (<6 hours) metabolic and hemod ynamic effects of the ingestion of a massive oral citric acid load. The pri ncipal findings included metabolic acidosis accompanied by an increase in t he plasma anion gap that was not caused by L-lactic acidosis, hyperkalemia, and the abrupt onset of hypotension. A unique feature was a dramatic clini cal improvement when ionized calcium was infused. The case illustrates the importance of considering the properties of the conjugate base (anion) of t he added acid because, in this instance, the citrate anion had a unique and life-threatening consequence (lower ionized calcium level) that was rapidl y reversible.