We are grateful to Drs. Kowalczyk and Farber for their thorough review and insightful response to our recent clinical focused review of the administration of fibrinogen to mitigate endothelial dysfunction after acute traumatic injury. We appreciate their constructive critique regarding the fibrinogen concentration in cryoprecipitate and welcome this opportunity to address the issue they have raised.

As Drs. Kowalczyk and Farber mention, there is a high degree of variability in the fibrinogen concentration of human-derived blood components, including cryoprecipitate and plasma. The correct fibrinogen concentration in cryoprecipitate units is 1,000 to 1,500 mg/dl. We admit to a mathematical error when deriving the fibrinogen concentration per single unit of product versus unit of volume which resulted in the 10-fold difference. We sincerely apologize to the readers and the editorial board of Anesthesiology for this error. Please note that the concentrations of fibrinogen we reported for plasma (about 270 mg/dl) and fibrinogen concentrate (2,000 mg/dl) are accurate. This important correction does not change the message of our review. Plasma-based resuscitation has decreased trauma-related mortality, but fibrinogen may play a more significant role than initially recognized. Indeed, preclinical work suggests that the survival benefit of plasma transfusion in trauma may be related, at least partly, to the mitigation of endotheliopathy of trauma. Fibrinogen may be the key factor in plasma that stabilizes the endothelial glycocalyx. Fresh frozen plasma is ineffective at repleting acquired hypofibrinogenemia, and therefore, anesthesiologists should consider administering cryoprecipitate or fibrinogen concentrate for this purpose. Further human studies are needed to confirm the relationship between fibrinogen replacement, improved stability of the endothelial glycocalyx, and mitigating the endotheliopathy of trauma.

We once again thank Drs. Kowalczyk and Farber for their reinforcement that anesthesiologists understand the importance of fibrinogen replacement and the accurate content of fibrinogen in the various products available.