Preventing venous thromboembolism in general medical inpatients and after an ischaemic stroke.

Clinical trials and meta-analyses have shown that low-molecular-weight heparin and unfractionated heparin are effective in preventing deep vein thrombosis (DVT) in acutely ill medical inpatients who are at risk as they are likely to be bedridden for 6 days or more. It is not known, however, if such prophylaxis can also reduce the likelihood of fatal pulmonary embolism or decrease all-causes mortality in this patient population. No recommendations can be made regarding thromboprophylaxis in those at a lower risk of venous thromboembolism or in short-stay inpatients, as these have not yet undergone clinical trial. Current evidence suggests that high doses of heparin should be avoided after an acute ischaemic stroke, as the results of recent large trials suggest any potential treatment benefit in preventing DVT is cancelled by the increased intracranial bleeding risk caused from the underlying disease.