Physical methods for preventing deep vein thrombosis in stroke

After a stroke, blood clots can form in the veins of the legs (deep vein thrombosis, or DVT). These clots can break off and be carried in the blood stream to the heart and lungs (causing pulmonary embolism). This can be life threatening. Although anticoagulant drugs can reduce the risk of DVT they can also cause serious bleeding. A number of physical methods have been developed to prevent DVT forming. These include wearing graduated compression stockings, intermittent pneumatic compression and electrical stimulation of leg muscles. The physical methods are used to increase the blood flow in the leg veins and reduce the risk of clots forming. We aimed to evaluate the effects of these physical methods in patients with a recent stroke. We found two randomised trials of graduated compression stockings, involving 2615 participants, and two small trials of intermittent pneumatic compression involving 177 participants. Graduated compression stockings were no better than 'best medical treatment' in reducing the risk of DVT after stroke. Stockings caused more skin problems (for example ulcers and blisters) on the legs. Intermittent pneumatic compression appeared promising but was not proven to be definitely beneficial. The evidence does not support routine use of graduated compression stockings or intermittent pneumatic compression in patients with a recent stroke. The trials that are ongoing at present should provide reliable evidence on the benefits and harms of intermittent pneumatic compression.

Authors' conclusions: 

Evidence from randomised trials does not support the routine use of GCS to reduce the risk of DVT after acute stroke. There is insufficient evidence to support the routine use of IPC to reduce the risk of DVT in acute stroke and further larger randomised studies of IPC are needed to reliably assess the balance of risks and benefits of this intervention.

Read the full abstract...

Deep vein thrombosis (DVT) and resulting pulmonary embolism (PE) are important complications of stroke. Physical methods to reduce the risk of DVT and PE, such as graduated compression stockings (GCS) or intermittent pneumatic compression (IPC) applied to the legs, do not appear to be associated with any bleeding risk and reduce the risk of DVT in some categories of surgical patients. We sought to assess their effects in stroke patients.


To assess the effectiveness and safety of physical methods of reducing the risk of DVT, fatal or non-fatal PE and death in patients with recent stroke.

Search strategy: 

We searched the Cochrane Stroke Group Trials Register (last searched November 2009), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2009), MEDLINE (1966 to November 2009), EMBASE (1980 to November 2009), CINAHL (1982 to November 2009) and The British Nursing Index (1985 to November 2009). We screened reference lists of all relevant papers, searched ongoing trials registers (November 2009) and contacted experts in the field.

Selection criteria: 

Unconfounded randomised controlled trials comparing physical methods for reducing the risk of DVT with control and in which prophylaxis was started within seven days of the onset of stroke.

Data collection and analysis: 

Two review authors searched for trials and extracted data.

Main results: 

We identified two trials of GCS that included 2615 patients and two small studies of IPC that included 177 patients. Overall, physical methods were not associated with a significant reduction in DVTs during the treatment period (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.70 to 1.04) or deaths (OR 1.12, 95% CI 0.87 to 1.45). Use of GCS was not associated with any significant reduction in risk of DVT (OR 0.88, 95% CI 0.72 to 1.08) or death (OR 1.13, 95% CI 0.87 to 1.47) at the end of follow up. IPC was associated with a non-significant trend towards a lower risk of DVTs (OR 0.45, 95% CI 0.19 to 1.10) with no evidence of an effect on deaths (OR 1.04, 95% CI 0.37 to 2.89).