Introduction: Traumatic subdural hemorrhages (tSDHs) are associated with high morbidity and mortality rates, and often require neurosurgical intervention. Risk of venous thromboembolism (VTE) in tSDH patients ranges from 2.2 to 14.1%, yet a consensus protocol on balancing chemoprophylaxis and hemorrhagic risk has not been established. An increased understanding of the risk factors for VTE in tSDH patients may inform development of prophylaxis guidelines.

Methods: Retrospective analysis of a prospectively maintained, single-institution Level I trauma center database was performed to identify the incidence and risk factors associated with formation of deep venous thrombosis (DVT) and pulmonary embolism (PE) in consecutive patients admitted for tSDHs from 1990-2015. Statistical analyses included multivariate logistic regression adjusted for demographic and clinical variables, with p <0.05 considered statistically significant.

Results: Of the 3024 patients (2211 male, 813 female) included in the study with a tSDH, 634 (20.9%) required neurosurgical intervention in the form of an intracranial pressure (ICP) monitor or craniotomy/craniectomy. Overall, 133 (4.4%) and 20 (0.7%) patients were diagnosed with a DVT or PE (mean age 54.3±21.1 and 49.1±20.8 years, respectively). Risk factors for DVT/PE formation included: age = 60 (OR: 1.71/4.38, p<0.03), injury severity score (ISS) = 20 (OR: 2.27/12.14, p<0.02), and intensive care unit (ICU) length of stay = 7 days (OR: 9.95/10.76, p=0.00). ICP monitor placement and craniectomy were also identified risk factors for DVT (OR: 3.86 and 3.50; p=0.00), but not PE formation.

Conclusions: While overall VTE risk is low for patients admitted with tSDH, the elderly and those with more severe injuries requiring neurosurgical intervention and prolonged ICU stays have significantly increased thrombotic risk. Development of tiered VTE prophylaxis regimens based on a patients' individual thrombotic risk profile may warrant future study.

Patient Care: By providing a better understanding of the risk factors for venous thromboembolism in patients with traumatic subdural hemorrhages, development of tiered VTE prophylaxis regimens based on a patients' individual thrombotic risk profile may be possible.

Learning Objectives: Understand the risk factors for venous thromboembolism in patients with traumatic subdural hemorrhages.

References: 1. Ryan CG, Thompson RE, Temkin NR, Crane PK, Ellenbogen RG, Elmore JG. Acute traumatic subdural hematoma: current mortality and functional outcomes in adult patients at a Level I trauma center. J Trauma Acute Care Surg. 2012;73(5):1348-1354. 2. Abdel-Aziz H, Dunham CM, Malik RJ, Hileman BM. Timing for deep vein thrombosis chemoprophylaxis in traumatic brain injury: an evidence-based review. Crit Care. 2015;19:96.