Prevention of venous thromboembolic risk in non-surgical patients.

The risk of deep-vein thrombosis in hospitalized medical patients varies considerably among diseases and should be systematically assessed as a function of the presence of different risk factors. The need for drug prophylaxis of thromboembolic risk in patients at moderate or high risk of thrombosis is now recommended. In such cases, only standard or low-molecular-weight heparins have been evaluated in controlled trials. The efficacy of heparin prophylaxis has been demonstrated in hospitalized cardiac patients following myocardial infarction, in neurological patients with paralysis of one or both lower limbs, and in intensive-care patients or in those with a serious medical condition, particularly if they have a history of deep-vein thrombosis. The choice between the different heparins, their dosages and treatment durations, and the possible indication for prophylaxis in patients at low thrombotic risk should be evaluated in controlled trials.