“…2 Acute myocardial infarction-We recommend low dose subcutaneous heparin as prophylaxis for venous thromboembolism7' in patients who are not already BMJ VOLUME 305 5 SEPTEMBER 1992 receiving higher doses of heparin (25 000 units/day intravenously or subcutaneously) for maintaining patency after thrombolytic therapy or for prophylaxis for mural thrombosis and reinfarction, or both. 19 31 Acute stroke-In patients with acute stroke causing lower limb weakness we recommend low dose subcutaneous heparin as prophylaxis for venous thromboembolism,2872 provided that intracranial haemorrhage and intracranial neoplasia have been excluded by computed tomographic brain scanning.73 Though low dose heparin and some low molecular weight heparins or heparinoids are effective in preventing deep vein thrombosis after stroke,727475 their effects on intracranial bleeding, functional outcome, and mortality remain to be established by larger studies.72 In patients in whom computed tomography is not performed, or who have intracranial haemorrhage or neoplasia or other contraindications to heparin, we recommend graduated compression stockings with or without intermittent pneumatic compression, extrapolating from controlled trials in neurosurgical patients.95 6 Other groups at moderate or high risk -In other groups (for example, those immobilised with chest infection, heart failure, respiratory failure, malignancy, inflammatory bowel disease and other conditions in table I) we recommend prophylaxis with low dose subcutaneous heparin'927; warfarin (in high risk patients-for example, those with previous thromboembolism); or in patients with contraindications to heparin and warfarin graduated compression stockings with or without intermittent pneumatic compression (extrapolating from trials in surgical patients '8-20 56).…”