Why is it important to maintain normal calcium levels during massive blood transfusion?

From the Guidelines

Maintaining normal calcium levels during massive blood transfusion is crucial to prevent hypocalcemia and its associated complications, such as cardiac arrhythmias, hypotension, and coagulopathy, as recommended by the European guideline on management of major bleeding and coagulopathy following trauma: sixth edition 1. The importance of normal calcium levels during massive blood transfusion cannot be overstated, as hypocalcemia can lead to serious complications. Stored blood products contain citrate as an anticoagulant, which binds to calcium and can rapidly deplete ionized calcium levels in the recipient, especially when large volumes are transfused quickly.

• The physiological basis for this concern is that calcium is crucial for normal cardiac contractility, vascular tone, and coagulation cascade function.
• Without adequate calcium, patients may experience decreased cardiac output, vasodilation, and impaired clot formation, which can worsen hemorrhagic shock in already critically ill patients receiving massive transfusions. To manage this, calcium levels should be monitored frequently during massive transfusion, and supplementation with calcium chloride (10% solution, 10-20 mL) or calcium gluconate (10% solution, 30-60 mL) should be administered intravenously when levels fall below normal or when signs of hypocalcemia appear 1.
• Calcium chloride is preferred in emergency situations as it provides three times more elemental calcium than calcium gluconate.
• The normal range of ionised calcium is 1.1–1.3 mmol/L, and levels below 0.9 mmol/L can lead to cardiac dysrhythmias 1. The European guideline on management of major bleeding and coagulopathy following trauma: sixth edition recommends monitoring ionised calcium levels and maintaining them within the normal range during massive transfusion, and administering calcium chloride to correct hypocalcaemia 1.
• Low ionised calcium levels at admission are associated with an increased mortality and an increased need for massive transfusion 1.
• Hypocalcaemia during the first 24 h can predict mortality and the need for multiple transfusion better than the lowest fibrinogen concentrations, acidosis, and the lowest platelet counts 1.

From the FDA Drug Label

Calcium is the fifth most abundant element in the body and the major fraction is in the bony structure. Calcium plays important physiological roles, many of which are poorly understood. It is essential for the functional integrity of the nervous and muscular systems It is necessary for normal cardiac function and is one of the factors that operates in the mechanisms involved in the coagulation of blood.

It is important to have calcium levels normal when doing massive blood transfusion because calcium is necessary for normal cardiac function and plays a role in the coagulation of blood 2. Maintaining normal calcium levels can help prevent cardiac complications and ensure proper blood coagulation during massive blood transfusion.

From the Research

Importance of Normal Calcium Levels in Massive Blood Transfusion

• Maintaining normal calcium levels is crucial during massive blood transfusion to prevent hypocalcemia, which is associated with increased mortality in trauma patients with hemorrhagic shock 3, 4.
• Hypocalcemia can occur due to citrate and serum calcium chelation during massive transfusion, and it can lead to coagulopathy and death 4, 5.
• Studies have shown that the incidence of hypocalcemia is higher in patients who receive massive transfusion, and it is more common in those who receive larger volumes of blood products 4, 5, 6.

Consequences of Hypocalcemia

• Hypocalcemia is associated with increased mortality, coagulopathy, and longer hospital stays 3, 4, 5.
• Severe hypocalcemia (ionized calcium < 0.9 mmol/L) is particularly dangerous and can lead to cardiac arrest and death 4, 5.
• Hypocalcemia can also lead to coagulopathy, which can worsen bleeding and increase the need for blood transfusions 4, 5.

Prevention and Treatment of Hypocalcemia

• Calcium replacement protocols can help prevent hypocalcemia during massive transfusion 3, 7.
• Monitoring of ionized calcium levels is crucial to detect hypocalcemia early and prevent its consequences 3, 4, 5.
• Calcium supplementation should be prioritized in any large volume transfusion, regardless of blood product type 6.
• Standardized protocols for recognition and management of severe hypocalcemia during massive transfusions may improve outcomes 5.