Calcium Administration in Massive Transfusion Protocols

Introduction to Calcium Replacement

The American College of Critical Care recommends calcium chloride as the preferred agent for calcium replacement during massive transfusion protocols, administered at 1 gram per liter of citrated blood products transfused to maintain ionized calcium levels above 0.9 mmol/L 1, 2

Ionized calcium levels should be monitored at baseline and every 4-6 hours during intermittent transfusions, or every 1-4 hours during continuous massive transfusion, with a normal range of 1.1-1.3 mmol/L that is pH-dependent 1, 2
Low ionized calcium at admission is associated with increased mortality, need for massive transfusion, platelet dysfunction, decreased clot strength, and coagulopathy 3

The Critical Care society recommends maintaining ionized calcium levels >0.9 mmol/L to support cardiovascular function and coagulation, and promptly correcting hypocalcemia when ionized calcium levels fall below 0.9 mmol/L or when total corrected calcium levels are ≤7.5 mg/dL 1, 2
Cardiac dysrhythmias are particularly concerning when ionized calcium is <0.8 mmol/L, and calcium chloride is the preferred agent for treatment of hypocalcemia during massive transfusion 1, 2

Hypocalcemia in trauma patients is often related to citrate toxicity from blood product transfusions, and is exacerbated by hypoperfusion, hypothermia, or hepatic insufficiency 1, 2
Colloid infusions can contribute to hypocalcemia, and calcium gluconate is not physically compatible with fluids containing phosphate or bicarbonate 3

Calcium chloride is more effective than calcium gluconate in patients with liver dysfunction due to faster release of ionized calcium, and requires less volume to deliver equivalent elemental calcium 1, 2
10 mL of 10% calcium gluconate contains only 90 mg of elemental calcium, one-third the elemental calcium of calcium chloride 1, 2