A reduction in clot formation rate and strength assessed by thrombelastography is indicative of transfusion requirements in patients with penetrating injuries

Abstract

Background: Bleeding is a major cause of death in patients with traumatic injuries. Recently, thrombelastography (TEG) has been suggested as an additional means of evaluating coagulation in trauma patients. We hypothesized that TEG data would aid in defining the coagulopathy of trauma in patients with penetrating traumatic injuries.

Methods: A retrospective study was performed of patients (n = 44) with penetrating injuries admitted to a combat support hospital during a 2-month period in 2004. Recorded data included standard laboratory data, TEG parameters, and blood product use in the first 24 hours after admission. Values were compared with clinically accepted ranges and those obtained from the Haemoscope Corporation.

Results: At admission, International Normalization Ratio, prothrombin time, and partial thromboplastin time were increased in 39% (>or=1.5), 31% (>16 seconds), and 37% (>40 seconds) of patients, respectively, suggesting hypocoagulation, but these variables did not correlate with the use of blood products (p > 0.05). TEG values obtained within 24 hours of admission (6 hours +/- 5.7 hours; median of 4.5 hours) demonstrated hypocoagulation based on delayed propagation of the clot (increased K time and reduced alpha-angle) and decreased clot strength (reduced maximal amplitude [MA]). MA correlated (r = 0.57, p < 0.01) with blood product use as well as platelet count (r = 0.61, p < 0.01). Patients with reduced MA (n = 23) used more blood products and had reduced platelet counts and hematocrit.

Conclusion: Thrombelastography was a more accurate indicator of blood product requirements in our patient population than prothrombin time, partial thromboplastin time, and International Normalization Ratio. Thrombelastography enhanced by platelet count and hematocrit can guide blood transfusion requirements.