Incidence and Risk Factors for Deep Venous Thrombosis and Its Impact on Outcome in Patients Admitted to Medical Critical Care

Abstract

Abstract Objectives: This study evaluated the incidence and risk factors for deep venous thrombosis (DVT) while on thromboprophylaxis, in patients admitted to the medical intensive care unit (MICU), and to assess its impact on outcomes.

Methods: Consecutive patients admitted to the MICU underwent compression ultrasound of the jugular, axillary, femoral, and popliteal veins at admission, day 3 and 7 to screen for DVT. All patients were on pharmacological and/or mechanical thromboprophylaxis as per protocol. The primary outcome was the incidence of DVT (defined as occurrence on day 3 or 7). Secondary outcomes were death and duration of hospitalization. Risk factors for DVT were explored using bivariate and multivariable logistic regression analysis and expressed as risk ratio (RR) with 95% confidence intervals (CIs).

Results: The incidence of DVT was 17.2% (95% CI 12.0, 22.3) (n = 35/203); two-thirds were catheter associated (23/35). There was no difference in mortality between those with and without incident DVT (9/35 vs 40/168, p = 0.81). The mean (SD) duration of hospitalization was longer in the DVT group (20.1 (17) vs 12.9 (8.5) days, p = 0.007). Although day 3 INR (RR 2.1, 95% CI 0.9–5.3), age >40 years (2.1, 0.8–5.3), vasopressor use (1.0, 0.4–2.9) and SOFA score (0.9, 0.85–1.1) were associated with the development of DVT on bivariate analysis, only central venous catheters (15.97, 1.9–135.8) was independently associated with DVT on multivariable analysis.

Conclusions: Despite thromboprophylaxis, 17% of ICU patients develop DVT. The central venous catheter is the main risk factor. DVT is not associated with increased mortality in the setting of prophylaxis.