What is hypocalcemia primarily caused by in blood transfusions?

Hypocalcemia in the context of blood transfusions is primarily caused by citrate, which is used as an anticoagulant in blood storage bags. Citrate binds calcium in the bloodstream, which prevents blood clotting during storage and maintains the liquid state of the blood. When a large volume of blood is transfused, the citrate can quickly chelate calcium in the recipient's blood, leading to a temporary decrease in serum calcium levels and resulting in hypocalcemia.

This condition may lead to various symptoms, including muscle spasms and cardiac complications, particularly in patients receiving massive transfusions. It is important for medical personnel to monitor calcium levels and be prepared to administer calcium replacement if significant hypocalcemia develops during or after a transfusion. The role of citrate in causing this hematological complication highlights the need for awareness and management strategies during transfusion practices.