Citrate Toxicity: Treatment
Basic, Organ-Based and Clinical Sciences
Citrate is used to prevent coagulation of stored blood products (primarily FFP and platelets, as well as cell saver). Citrate chelates calcium and magnesium, leading to hypocalcemia and hypomagnesemia when large amounts are transfused (greater than 6 units/hr in adults). Symptoms of citrate toxicity are related to hypocalcemia and hypomagnesemia, including hypotension, myocardial depression, EKG changes (QT prolongation, heart block, arrhythmias), nervous system hyperexcitability (laryngospasm, tetany, Chvostek’s sign, Trousseau sign), and coagulopathy. These effects can be more pronounced in patients with hepatic dysfunction, hypoalbuminemia, hypothermia or hyperventilation, as well as in pediatric patients. Treatment is primarily aimed at restoring calcium (IV calcium gluconate or chloride) and magnesium. Additionally, citrate is usually rapidly metabolized by the liver, so slowing the rate of transfusion will allow for hepatic metabolism as well as treatment of hypocalcemia/hypomagnesemia.