Thromboelastography as a Better Indicator of Hypercoagulable State After Injury Than Prothrombin Time or Activated Partial Thromboplastin Time

J Trauma. 2009 Aug;67(2):266-75; discussion 275-6. doi: 10.1097/TA.0b013e3181ae6f1c.

Abstract

Objectives: To investigate the hemostatic status of critically ill, nonbleeding trauma patients. We hypothesized that a hypercoagulable state exists in patients early after severe injury and that the pattern of clotting and fibrinolysis are similar between burned and nonburn trauma patients.

Materials: Patients admitted to the surgical or burn intensive care unit within 24 hours after injury were enrolled. Blood samples were drawn on days 0 through 7. Laboratory tests included prothrombin time (PT), activated partial thromboplastin time (aPTT), levels of activated factor XI, D-dimer, protein C percent activity, antithrombin III percent activity, and thromboelastography (TEG).

Results: Study subjects were enrolled from April 1, 2004, to May 31, 2005, and included nonburn trauma patients (n = 33), burned patients (n = 25), and healthy (control) subjects (n = 20). Despite aggressive thromboprophylaxis, three subjects (2 burned and 1 nonburn trauma patients [6%]) had pulmonary embolism during hospitalization. Compared with controls, all patients had prolonged PT and aPTT (p < 0.05). The rate of clot formation (alpha angle) and maximal clot strength were higher for patients compared with those of controls (p < 0.05), indicating a hypercoagulable state. Injured patients also had lower protein C and antithrombin III percent activities and higher fibrinogen levels (p < 0.05 for all). Activated factor XI was elevated in 38% of patients (control subjects had undetectable levels).

Discussion: Thromboelastography analysis of whole blood showed that patients were in a hypercoagulable state; this was not detected by plasma PT or aPTT. The high incidence of pulmonary embolism indicated that our current prophylaxis regimen could be improved.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Antithrombin III / analysis
  • Case-Control Studies
  • Factor XIa / analysis
  • Female
  • Humans
  • Intensive Care Units
  • Male
  • Middle Aged
  • Partial Thromboplastin Time
  • Protein C / analysis
  • Prothrombin Time
  • Pulmonary Embolism / diagnosis
  • Pulmonary Embolism / etiology
  • Thrombelastography*
  • Thrombophilia / diagnosis*
  • Thrombophilia / etiology*
  • Venous Thromboembolism / diagnosis
  • Venous Thromboembolism / etiology
  • Wounds and Injuries / complications*

Substances

  • Protein C
  • Antithrombin III
  • Factor XIa