Calcium Administration in Life-saving Management During Massive Hemorrhage

The treatment of hemorrhage with blood products has been well studied, however very little literature exists on the administration of specific electrolytes such as calcium. Citrate is added to blood products to prevent coagulation by chelating free calcium. This process reduces serum calcium and can lead to hypocalcemia, especially in trauma patients who have altered metabolism, hypovolemia, and receive large quantities of blood products. The majority of trauma patients have hypocalcemia upon arrival at the hospital. Serum hypocalcemia in trauma patients matters because calcium is crucial for bleeding control due to its contributions to platelet function, coagulation, and vasoconstriction. Calcium is also essential for other physiological functions during trauma, such as heart and smooth muscle contractility. It is likely due to these key roles that the literature demonstrates hypocalcemia's association with increased mortality, bleeding, blood transfusion requirements, and coagulopathy.

The primary objective of our proposed trial is to assess the feasibility of conducting an interventional calcium trial on patients undergoing the Massive Hemorrhage Protocol (MHP). Feasibility will be evaluated through the recruitment of patients, adherence to protocol, as well as assessment of any protocol violations that occur during the trial. Secondary objectives of our trial include analyzing the effect calcium supplementation has on patient ionized calcium (iCa) level, total blood product transfused, hemodynamic instability, ICU mortality, and hospital mortality.

The investigators will complete a single-centre, double-blinded randomized control feasibility trial. Both trial arms will receive study drug in accordance with Ontario's Massive Hemorrhage Protocol (MHP). After every 4 units of RBCs, the treatment group will receive 3g of calcium gluconate and the control arm will receive saline placebo. Results will be assessed for feasibility to inform the development of a larger trial.

Inclusion criteria

• Adult trauma patients undergoing the MHP at Victoria Hospital, London, Ontario

Exclusion criteria

• Under the age of 18
• Pregnant