Objectives: To determine the prevalence and risk factors of asymptomatic lower-limb deep venous thrombosis (DVT) among Asians in inpatient rehabilitation after traumatic brain injury (TBI).
Design: a prospective observational study.
Participants: Fifty-six (35 males and 21 females) Asian individuals with TBI with a median of 25 days to rehabilitation. The mean age was 49.3 +/- 20.4 years and 64.3% (36) were Chinese, 19.6% (11) were Malay, 10.7% (6) were Indian, and 5.4% (3) were of other races.
Main measures: quantitative D-dimer assay (DDA) and targeted hemiplegic/weaker lower extremity venous duplex ultrasonography (VDU) for patients with elevated DDA levels (>or=0.34 microg/mL). Outcome measures included the incidence of DVT based on VDU diagnosis.
Results: All 34 (60.7%) patients who had elevated DDA levels underwent single limb VDU, revealing an incidence of 5.4% (3) of lower-limb DVT, including 1 case of proximal and 2 of distal DVT. Logistic regression analyses did not reveal any significant predictive factors for DVT, but tracheostomy, higher admission Glasgow Coma Scale (GCS) score, and lower Functional Independence Measure (FIM)-walk scores correlated significantly with elevated DDA levels (P < .05). Receiver-operating characteristic analysis showed that cutoff DDA levels of 1.37 mg/mL resulted in a sensitivity of 100% and a specificity of 67.7%.
Conclusion: Asymptomatic DVT is uncommon in Asian TBI rehabilitation patients. Our low incidence could be related to the small sample size, ethnic protective factors, early walking during rehabilitation, and timing of VDU during possible declining thrombotic risk.