Another interesting and informative review article from the New England Journal of Medicine:
Particularly informative for trauma anesthesiologists and residents preparing for board certification or the in-training examination is the section on “Major Bleeding.”
The bullets for my residents are these:
- There is little quality evidence on the use of blood products in managing major bleeding.
- Without randomized trials, more and earlier FFP is administered to trauma victims owing to observations in military and civilian casualties that show improved bleeding control with a 1:1 ratio of PRBCs:FFP.
- Ratios of PRBCs:FFP of 1:1 or 1:2 are now widespread and increase the risk of Transfusion Related Acute Lung Injury (TRALI) and ARDS.
- In the USA, massive transfusions protocols have become driven by these ratios.
- Administration of more than 6 units FFP increases the risk of ARDS by 12 and of multiple organ dysfunction syndrome by 6.
- The North American Pragmatic, Randomized Optimal Platelets and Plasma Ratios (PROPPR) study (ClinicalTrials.gov number, NCT01545232) is comparing the effect of various ratios of blood products administered to trauma patients who are predicted to require massive transfusion (>10 U of packed red cells within the next 24 hours) on rates of death at 24 hours and 30 days.
- In Europe FFP has largely been abandoned. Instead, factor concentrates (prothrombin complex concentrate, factor XIII, and fibrinogen) are used exclusively on the basis of elastography determinations.
- Some in Europe believe that the treatment of major hemorrhage should begin with fibrinogen concentrate supplementation and tranexamic acid (TXA), a synthetic derivative of lysine that acts as an antifibrinolytic agent by competitively inhibiting plasminogen, with red cells and intravenous fluid used on an as-needed basis.
- Fibrinogen is the factor that ultimately forms fibrin, the ligand for platelet aggregation. It is the factor that is most required. This requirement reflects increased consumption, loss, dilution, and fibrinogenolysis. Consequently, guidelines for the management of traumatic bleeding now indicate that the trigger level for supplementing fibrinogen should be 1.5 to 2.0 g per liter rather than 1.0 g per liter.9
- TXA should be administered to all patients with major bleeding after trauma. In the CRASH-2 study, 20,000 trauma patients with bleeding or risk of major bleeding randomly received TXA or placebo. TXA given within 3 hours after injury reduce deaths from bleeding by a third. TXA should be administered as soon as possible after injury and within 3 hours. There appears to be increased mortality if administered more than 3 hours after injury.