Thromboprophylaxis in medical patients--why not for all?

Venous thromboembolism (VTE) is a major problem in non-surgical patients admitted to the hospital, both during the hospitalization period and after discharge. Risk factors for VTE are well known and scoring systems have been published. Nevertheless, prophylaxis against VTE is in many hospitals used less often than ideal and also inappropriately. Electronic tools to alert the physicians to provide prophylaxis and suggest suitable measures have shown promising results with a reduction of clinically relevant VTE. Large randomized clinical trials have demonstrated efficacy of low molecular-weight heparin (LMWH), pentasaccharide(fondaparinux) and unfractionated heparin. The results were, however, driven by asymptomatic deep vein thrombosis (DVT), including distal DVT in some studies. A reduction of pulmonary embolism is achieved, but without any significant effect on the mortality. The agents are generally safe, with only a small increase of major bleeding, less with LMWH than with unfractionated heparin. The challenge is still to direct the efforts to the most appropriate patients.