Evaluation of pharmacological thromboprophylaxis in critically Ill elderly patients: A multicenter cohort Study

Older adults are at a higher risk of developing venous thromboembolism (VTE), particularly when admitted to the Intensive Care Units (ICUs). Parenteral anticoagulation is the primary method used for thromboprophylaxis in critically ill patients.Nonetheless, there is limited evidence on the most effective pharmacological agents for thromboprophylaxis and their dosages specifically for older adults in critical care settings..

This study aims to evaluate the effectiveness and safety of pharmacological VTE prophylaxis in critically ill older adults.

This multi-center retrospective cohort study involved critically ill older adults aged 65 and above who were admitted to ICUs and received pharmacological thromboprophylaxis. Patients were categorized into two sub-cohorts based on the type of pharmacological thromboprophylaxis they received: subcutaneous unfractionated heparin (UFH) or low molecular weight heparin (LMWH); enoxaparin. The primary endpoint was major bleeding, while secondary endpoints were minor bleeding, all thrombosis cases, ICU and hospital length of stay, mechanical ventilation (MV) duration, and other ICU complications. A propensity score (PS) matching was utilized using a (2:1) ratio between patients who received UFH and enoxaparin as prophylaxis.

After PS matching, we included 210 patients based on predefined criteria, with 140 patients in the UFH group and 70 in the enoxaparin group. The major bleeding events were lower in the enoxaparin group compared with UFH (10.7 % to 2.9 %; p-value=0.05); however, it failed to reach the statistical significance at regression analysis (OR: 0.25, 95 %CI: 0.10, 1.13; P = 0.07). All thrombotic events and rate of minor bleeding were not statistically significantly different between the two groups (OR 1.29, 95 % CI: 0.58, 2.84; P-value= 0.53 and OR: 0.54, 95 % CI: 0.25, 1.14, P = 0.11, respectively). In addition, the 30-day and in-hospital mortality rates were not statistically significantly different between the two groups (OR: 0.75, 95 %CI: 0.37, 1.52, P = 0.43 and OR: 0.65, 95 %CI: 0.33, 1.30, P = 0.21, respectively).

Enoxaparin as VTE prophylaxis in critically ill older adults showed a trend towards lower rates of major bleeding, although the difference was not statistically significant. In contrast, there were no notable differences in thrombosis rates among this patient group. Future randomized controlled trials are required to confirm our findings and explore long-term outcomes.