Pharmacological and Mechanical Thromboprophylaxis in Critically Ill Patients: a Network Meta-Analysis of 12 Trials

Thromboprophylaxis for venous thromboembolism is widely used in critically ill patients. However, only limited evidence exists regarding the efficacy and safety of the various thromboprophylaxis techniques, especially mechanical thromboprophylaxis. Therefore, we performed meta-analysis of randomized controlled trials (RCTs) that compared the overall incidence of deep vein thrombosis (DVT) for between unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), and intermittent pneumatic compression (IPC) in critically ill patients. A Bayesian random effects model for multiple treatment comparisons was constructed. The primary outcome measure was the overall incidence of DVT at the longest follow-up. The secondary outcome measure was the incidence of major bleeding, as defined by the original trials. Our analysis included 8,622 patients from 12 RCTs. The incidence of DVT was significantly lower in patients treated with UFH (OR, 0.45; 95% CrI, 0.22-0.83) or LMWH (OR, 0.38; 95% CrI, 0.18-0.72) than in patients in the control group. IPC was associated with a reduced incidence of DVT compared to the control group, but the effect was not statistically significant (OR, 0.50; 95% CrI, 0.20-1.23). The risk of DVT was similar for patients treated with UFH and LMWH (OR, 1.16; 95% CrI, 0.68-2.11). The risk of major bleeding was similar between the treatment groups in medical critically ill patients and also in critically ill patients with a high risk of bleeding. In critically ill patients, the efficacy of mechanical thromboprophylaxis in reducing the risk of DVT is not as robust as those of pharmacological thromboprophylaxis.