the ligand for platelet aggregation, and in patients
with major bleeding, it is required to a
larger extent than any other hemostatic protein.8
In such patients, this requirement reflects increased
consumption, loss, dilution, and fibrino
genolysis. On the basis of these multiple roles,
even in the absence of evidence from randomized,
controlled trials, 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 It is unknown whether early fibrinogen
supplementation and the use of prothrombin
complex concentrate, as compared with the
use of fresh-frozen plasma, improves clinical
outcomes in patients with major bleeding. Future
randomized, controlled trials should assess the
overall benefit and safety, including the rate of
hospital-acquired venous thromboembolism.10,11
Similarly, the use of recombinant factor VIIa,
which has been shown to reduce the use of red
cells in bleeding but not to reduce mortality,
needs further evaluation. Data from placebocontrolled
trials have shown that the off-label
use of recombinant factor VIIa significantly increased
the risk of arterial thrombosis.12,13