European guidelines on peri-operative venous thromboembolism prophylaxis: first update.

Abstract

Monitoring hypercoagulation in trauma patients RationaleIt is now well recognised that in the acute phase, after major trauma, the coagulation system is dynamic and, particularly in bleeding patients with trauma-induced coagulopathy or severe brain injury, a hypercoagulable phenotype develops universally within 24 to 48 h. 1 Achieving adequate venous thromboembolism prophylaxis (VTEp) in trauma patients remains challenging for several reasons and despite standardised protocols to administer low-molecular-weight heparin (LMWH), up to 18% of critically injured patients will develop deep venous thrombosis (DVT) or pulmonary embolism despite pharmacoprophylaxis. 2 Measuring serum anti-Xa levels has been proposed to help titrate VTEp, with consensus defining prophylactic anti-Xa levels as 0.2 to 0.4 IU ml À1 for peak measurements or 0.1 to 0.2 IU ml À1 for trough levels, with values below this being subprophylactic. 3 Studies have shown that prophylactic anti-Xa levels compared with subprophylactic levels predict the risk of a clinically significant VTE in trauma patients. [4][5][6] Two studies have reported that anti-Xa-guided dosing of LMWH reduces the rate of VTE after trauma compared with a standard fixed dose of enoxaparin. 7,8 However, a more recent large single centre study has failed to show any benefit of anti-Xa guided dosing for VTEp. 9 Weight-adjusted protocols for LMWH are used in published guidelines 10 based on a handful of studies demonstrating improved rates of prophylactic anti-FXa levels and overall lower VTE rates.