San Francisco Injury Center (SFIC) »  Full Research Descriptions »  Hemostatic Resuscitation and Traumatic Coagulopathy

Hemostatic Resuscitation and Traumatic Coagulopathy; Effect of Platelet Number and Function on Coagulopathy and Outcome after Trauma

Project Director/Lead Investigator: Mitchell Cohen, MD

Brief Summary of Project: Coagulopathy is present in 25-38% of trauma patients on arrival to the hospital and these patients are four times more likely to die. Recently, a high Fresh Frozen Plasma (FFP):Packed Red Blood Cell (PRBC) ratio has been shown to decrease mortality in massively transfused trauma patients. Therefore, we hypothesized that patients with coagulopathy on arrival to the hospital may benefit more from transfusion with a high ratio of FFP:PRBC than those who are not coagulopathic.

Recent studies have also shown that platelets play a central role in hemostasis after trauma. However, the platelet count of most trauma patients does not fall below the commonly taught "normal range" (150K-450K), and as a result, little attention has been paid to admission platelet count as a predictor of outcome. We examined the relationship between admission platelet count and outcome after trauma.

Specific Aims:
1. To determine if coagulopathic patients benefit more than non-coagulopatic patients from transfusion with a high ratio of FFP:PRBC.
2. To examine the relationship between admission platelet count and outcome after trauma.
3. To suggest an optimal transfusion protocol for acutely injured patients.

Studies/Results: We conducted two studies. The first was a retrospective multi-center cohort study of 452 massively transfused trauma patients to determine if the effect of the ratio of FFP:PRBC on death at 24 hours is modified by a patient's coagulation status on arrival to the hospital. Data collection is complete and data analysis is nearing completion. Preliminary analysis indicates that those who arrived to the hospital with coagulopahty had a greater risk of death than those without coagulopathy. However, as the ratio of FFP:PRBC transfused increased, mortality decreased similarly between the two groups. Most of the decrease occurred with transfusion of at least one half unit of FFP for every one unit of PRBCs transfused.

The second was a retrospective cohort study of 389 massively transfused trauma patients to test the association between admission platelet count and 24 hr mortality and units of PRBCs transfused. Data collection is complete and data analysis is nearing completion. Preliminary results indicate that admission platelet count was inversely correlated with 24 hour mortality and transfusion of PRBCs.

Significance: The mortality benefit from a high FFP:PRBC ratio is similar for all massively transfused trauma patients. This is contrary to the current belief that coagulopathic trauma patients benefit most from a high FFP:PRBC ratio. Furthermore, it is unnecessary to determine whether coagulopathy is present before transfusing a high FFP:PRBC ratio. Further studies are needed to determine the mechanism by which a high FFP:PRBC ratio decreases mortality in all massively transfused trauma patients.

Admission platelet count was inversely correlated with 24 hr mortality and transfusion of PRBCs. Our results suggest that a normal platelet count may be insufficient after severe trauma, and as a result, these patients may benefit from a lower platelet transfusion threshold.

The first abstract was accepted and presented at the American College of Surgeons surgical forum, October, 2010. A corresponding manuscript has been written and is in press at the Journal of Trauma. Results from the second study were presented at the American Association for the Surgery of Trauma (AAST) in September 2010. The corresponding manuscript is also in press at the Journal of Trauma.

 

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