The association of coagulopathy and traumatic brain injury in patients with isolated head injury

Abstract

The emergence of prothrombotic agents (e.g. activated factor VII) to treat traumatic brain injury (TBI) requires a better understanding of the association of coagulopathy with isolated head injury (IHI).

Objective: To investigate the association of IHI and coagulopathy.

Methods: Prospective, observational study in an urban level I trauma center.

Inclusion criteria: Adult (> or = 13 years of age) patients with IHI.

Exclusion criteria: patients with known coagulopathies or on anticoagulant therapy.

Predictor variables: TBI (head abbreviated injury severity score > 2, or brain hematoma on CT scan), age, gender, mechanism of injury, Glasgow Coma Score (GCS), and loss of consciousness (LOC).

Outcome variables: coagulopathy defined as elevated International Normalized Ratio (INR > 1.3) or activated partial thromboplastin time (PTT) greater than 34 s. We divided IHI subjects into two groups of patients with and without TBI.

Statistical analysis: Fisher's exact test and Mann-Whitney U were used to compare data where appropriate (alpha: 0.05, two-tailed).

Results: From July 2005 to December 2006, 276 patients with IHI were studied. The median age was 35 years (interquartile range: 25-52) with a 79% male predominance and 88% blunt trauma. Eight percent (95% CI, 5-12%) of patients had coagulopathy. The rate of coagulopathy in TBI patients (17%) was significantly higher than non-TBI patients (6%) (11% difference, 95% CI, 3-20%]. The relative risk of coagulopathy in TBI patients was 2.9 (95% CI, 1.3-6.6).

Conclusion: Coagulopathy as defined by elevated INR and/or PTT is associated with TBI after isolated head injury.