Recombinant factor VIIa is effective at reversing coagulopathy in a lactic acidosis model.

Background: The interplay of coagulopathy, acidosis, and hypothermia contributes to the death of the most seriously injured trauma patients. Because of in vitro testing and retrospective series, current recommendations advise correcting acidosis before administering recombinant factor VII (rFVIIa).

Methods: A lactic acidosis was induced in 40 kg swine, and 10 blood samples were withdrawn for testing. rFVIIa was added to the samples with and without bicarbonate correction of the pH. Conventional coagulation assays as well as rotational thromboelastography (ROTEM) were performed on these in vitro samples. Additionally, 10 acidotic and coagulopathic animals had rFVIIa administered after randomization to pH correction with bicarbonate, or remaining acidotic. Conventional coagulation and ROTEM assays were performed on the animals.

Results: Ex-vivo samples had a mean pH of 7.14 and International Normalized Ratio (INR) of 1.46. Addition of rFVIIa to these samples corrected the INR to 0.98 (p < 0.05). A similar effect was seen for the ROTEM extem Clotting Time (extem CT). Bicarbonate correction alone of these samples had only a modest effect on INR (1.36, p < 0.05). When administered in vivo to acidotic animals (pH, 7.15), rFVIIa lowered the INR from 1.49 to 1.01 (p < 0.05). Similar improvements in extem CT were seen.

Conclusions: rFVIIa is effective at reversing the coagulopathy from lactic acidosis in a large animal model. Recommendations against its use in acidotic patients may not be valid.