32M BIBEMS s/p SW to abdomen. He becomes hypotensive/tachycardic, becomes less responsive. Massive transfusion protocol is initiated.

  • What electrolyte abnormality is caused by massive transfusion?
  • In the 1:1:1 ratio, are we talking about a single dose of platelets or a single unit of platelets?

1) Due to large quantity of citrate being administered (~3g citrate per unit of RBC), massive transfusion can lead:

  • Hypocalcemia – Citrate binds to ionized calcium. Look out for signs of hypocalcemia including tetany, hypotension, prolonged QTc. Monitor ionized calcium level
  • Hyperkalemia (especially if using older blood and in patients with CKD)
  • Metabolic alkalosis (citrate metabolism produces HCO3)

*Citrate is metabolized by the liver, so inc risk in patients with hepatic dysfunction.

2) The 1:1:1 refers to Plasma:PLT:RBC where the PLT is measured in units

  • 1 adult dose of platelets = 1 unit of apheresis platelets = 5-6 units of random donor platelet units

(i.e. 6U plasma:1 dose of platelets:6U RBCs)


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  • Holcomb et al. Transfusion of plasma, platelets, and red blood cells in a 1:1:1 vs a 1:1:2 ratio and mortality in patients with severe trauma. JAMA. 2015;313(5):471-482.
  • http://www.trauma.org/archive/resus/massive.html
  • Spinella PC, Holcomb JB. Resuscitation and transfusion principles for traumatic hemorrhagic shock. Blood Rev. 2009 Nov;23(6):231-40.