What are the recommendations for managing massive blood transfusions to prevent complications such as hypocalcemia, dilutional coagulopathy, and hypothermia?

From the Guidelines

When administering multiple units of blood, it is essential to give calcium chloride 1g or calcium gluconate 3g intravenously when ionized calcium levels fall below 1.0 mmol/L or after every 4 units of blood products to prevent hypocalcemia. To manage massive blood transfusions effectively and prevent complications such as hypocalcemia, dilutional coagulopathy, and hypothermia, several key strategies should be employed.

• Implement a 1:1:1 ratio of packed red blood cells, fresh frozen plasma, and platelets to closely mimic whole blood composition 1.
• Administer calcium supplementation, with calcium chloride being the preferred agent due to its higher elemental calcium content compared to calcium gluconate, as noted in the European guideline on management of major bleeding and coagulopathy following trauma: sixth edition 1.
• To prevent dilutional coagulopathy, consider administering cryoprecipitate (10 units) when fibrinogen levels drop below 1.5 g/L, and tranexamic acid 1g IV over 10 minutes followed by 1g over 8 hours to reduce fibrinolysis 1.
• Maintain normothermia using fluid warmers set at 41°C for all infusions, forced-air warming blankets, and warmed humidified oxygen, as hypothermia can significantly increase mortality and worsen coagulopathy 1.
• Regular monitoring of coagulation parameters (PT, PTT, fibrinogen, platelet count), electrolytes (especially calcium, potassium, and magnesium), acid-base status, and core temperature is crucial for early detection and management of potential complications 1. These interventions are critical because stored blood products lack clotting factors and platelets, contain citrate (which binds calcium), and are stored cold, all of which can worsen bleeding and lead to metabolic derangements if not properly managed during massive transfusion.

From the FDA Drug Label

Calcium Gluconate Injection is a form of calcium indicated for pediatric and adult patients for the treatment of acute symptomatic hypocalcemia. Contains 100 mg of calcium gluconate per mL which contains 9.3 mg (0.465 mEq) of elemental calcium Administer intravenously (bolus or continuous infusion) via a secure intravenous line Individualize the dose within the recommended range in adults and pediatric patients depending on the severity of symptoms of hypocalcemia, the serum calcium level, and the acuity of onset of hypocalcemia.

To manage massive blood transfusions and prevent complications such as hypocalcemia, calcium gluconate should be administered intravenously. The dose should be individualized based on the severity of symptoms, serum calcium level, and acuity of onset of hypocalcemia.

• Dilute Calcium Gluconate Injection prior to use in 5% dextrose or normal saline.
• Administer Calcium Gluconate Injection intravenously via a secure intravenous line.
• Monitor patients, vitals, and electrocardiograph (ECG) during administration.
• Measure serum calcium every 4 to 6 hours during intermittent infusions and every 1 to 4 hours during continuous infusion 2.

From the Research

Managing Massive Blood Transfusions

To prevent complications such as hypocalcemia, dilutional coagulopathy, and hypothermia during massive blood transfusions, several recommendations can be considered:

• Calcium replacement protocols can be effective in reducing the incidence of hypocalcemia, as seen in a study where the implementation of a calcium replacement protocol significantly lowered the incidence of hypocalcemia in trauma patients undergoing massive transfusion protocols (MTPs) 3.
• The use of calcium gluconate infusion can help maintain plasma ionized calcium levels during therapeutic plasma exchange (TPE), with different concentrations of calcium gluconate added to replacement fluid showing varying effects on ionized calcium levels 4, 5, 6.
• Monitoring of ionized calcium levels and standardized protocols for recognition and management of severe hypocalcemia during massive transfusions may improve outcomes, as severe hypocalcemia commonly occurs during MTP activations and correlates with the number of packed red blood cells transfused 7.
• Prophylactic addition of calcium gluconate to replacement fluid can be safe and effective in maintaining ionized calcium levels throughout the procedure, with lower chances of adverse events related to hypocalcemia 5.

Prevention of Hypocalcemia

Prevention of hypocalcemia is crucial during massive blood transfusions, and the following strategies can be employed:

• Infusion of calcium gluconate at a rate of 1.6 g/h can stabilize plasma ionized calcium levels and prevent hypocalcemic reactions during TPE 4.
• Addition of 18.6 mg of elemental calcium/100 ml of 5% Human Serum Albumin (HSA) to replacement fluid can maintain ionized calcium levels throughout the procedure 5.
• Standardized protocols for calcium replacement can help reduce the incidence of hypocalcemia and improve outcomes in trauma patients undergoing MTPs 3.

Considerations for Massive Transfusions

When managing massive blood transfusions, the following considerations should be taken into account:

• The volume of blood products transfused can correlate with the prevalence of hypocalcemia, with patients receiving 13 or more units of packed red blood cells having a greater prevalence of hypocalcemia 7.
• Monitoring of ionized calcium levels and the amount of calcium supplementation administered can vary considerably, highlighting the need for standardized protocols 7.
• Severe hypocalcemia can contribute to coagulopathy and mortality in severely injured patients, emphasizing the importance of prompt recognition and management 7.