When is the optimum time to initiate pharmacological thromboprophylaxis in older adults after Traumatic brain injury?

Introduction:

Traumatic brain injury (TBI) is a significant cause of morbidity and mortality globally, most precipitated by falls in older adults (1). Beyond immediate risks, venous thromboembolism (VTE) represents a significant yet preventable complication in affected patients. A key challenge is determining the best time to initiate pharmacological thromboprophylaxis in TBI patients due to the risk of progression of the intracranial haemorrhage. Previous studies suggest early initiation (24–72 hours) may be safe and beneficial  (2).  We conducted a retrospective review to evaluate our current practices and clinical outcomes associated with timing of VTE prophylaxis in elderly patients with conservatively managed TBI.  

Methodology;

Patients aged ≥65 years admitted under major trauma and orthogeriatric teams between January 2024 and January 2025 were included. Data were obtained from electronic medical records. Patients transferred to neurosurgical services were excluded. The primary outcomes included VTE events, ICH progression, 30-day mortality, and length of stay. The project is registered with the audit department; the audit registration number is AUDI004811.

Results:

Seventy-six patients were included (39 male, 37 female; age range 67–95 years). Injury subtypes included subdural haematoma (33%), subarachnoid haemorrhage (19%), intraparenchymal haemorrhage (12%), and mixed injury patterns (36%). Pharmacological VTE prophylaxis was initiated within 72 hours in 25% of patients, after 72 hours in 36%, and not administered in 39%. Only two VTE events (pulmonary emboli) were observed, with no consistent association with timing of prophylaxis initiation. No cases of TBI progression were identified following initiation of pharmacological prophylaxis. Thirty-day all-cause mortality (n=6/74) was predominantly attributable to non-neurological causes and did not differ significantly between early and delayed prophylaxis groups. Average length of stay ranged from 11 to 30 days, longest in patients with mixed injury patterns.

Conclusion:
These findings support the safety of early thromboprophylaxis in selected patients and demonstrate the need for a balanced, individualised approach that considers both thrombotic and bleeding risks rather than relying solely on arbitrary time thresholds. Development of clear, locally agreed protocols-potentially incorporating repeat imaging and multidisciplinary decision making may help reduce practice variability amongst clinicians.