Coagulopathy and tranfusion

A low ratio of fresh frozen plasma to RBCs decreases mortality in patients receiving massive transfusions at a combat support hospital (Borgmann MA et al, J Trauma 2007;63:805 – 813).  The authors performed a retrospective review of the records from 246 soldiers with combat injuries who received massive transfusions (> 10 units of RBC in 24 h).  In the paper’s introduction the authors note that about 5% of patients admitted to Iraq US combat support hospitals require massive transfusion.  They note that mortality rates among these patients is more than 30% and that a considerable portion of this mortality appears related to the lethal triad of hypothermia, metabolic acidosis and coagulopathy.  Penetrating injuries were present in 94% of the group, 1% of the injured were female, and the median age was 24.  The median injury severity score (ISS) was 18 and the overall mortality was 28%.  The authors used a statistical process to divide the group into low, medium and high plasma to RBC groups with the low group having a plasma to RBC ratio of 1:8, the medium having a ratio of 1:2.5 and high with a ratio of 1:1.4.  Mortality decreased as the ratio of fresh frozen plasma to RBCs increased with a mortality of 65% in the low, 34% in the medium and 19% in the high group.  With respect to primary cause of death, hemorrhage related death was less in the high ratio group (37%) compared to the low ratio group (92.5%) producing a relative reduction of 60%.  The authors concluded that for patients with significant traumatic injuries requiring massive transfusion survival improved when fresh frozen plasma and RBCs are administered in near equal volumes (a ratio of 1:1.4).  The authors noted that those patients who received large amounts of fresh frozen plasma early required less total fluid in the first 24 hours.  They also noted that those in the low or medium plasma to RBC ratio groups often died of hemorrhage with a median time of death of 2 to 4 hours.  Remember however that this is a retrospective study with the high, medium and low ratio group created after the fact.

David S. Smith, M.D., Ph.D.