Intermittent pneumatic compression and anti-embolic stockings are both proven and established non-invasive mechanical methods of DVT prophylaxis that are effective when used either alone or, for higher risk patients, used in combination with pharmacological prophylaxis. Mechanical methods have the additional advantage in that they are not associated with a risk of bleeding.
Unlike pharmacological methods, both IPC and AES work to mitigate not one but two of the risk factors associated with VTE development: venous stasis and hypercoagulability. These mechanical methods of VTE prophylaxis are attractive to clinicians as there is no risk of bleeding when used as a monotherapy and they can be used as an adjunct to pharmacological methods to increase effectiveness in high-risk patients.
IPC therapy is delivered through inflatable, single-patient-use, garments containing one or more air chambers. These are applied to the foot, calf or calf and thigh and intermittently inflated with air by means of a powered pneumatic pump.
The inflation - deflation cycle simulates the normal ambulatory calf and foot pump and propels the blood of the deep veins towards the heart. This benefits the non-ambulatory patient by:
AES are designed to exert sustained graduated compression to the legs decreasing from the ankle towards the knee and thigh. This mechanical support to the leg decreases the cross-sectional profile of the vein, which increases venous velocity 2 (Autar 2009).
AES also prevent the pathological progression of passive venous distension to the point where sub-endothelial tears and activation of clotting factors might occur 3,4 .
In 1975 Sigel 5 identified an optimal stocking compression profile ranging from 18mmHg compression at the ankle to 8mmHg compression at the mid-thigh. Commonly known as the Sigel profile, this is the standard against which all AES performance is compared 6.
1 Kumar S, Walker M. The effects of intermittent pneumatic compression on the arterial and venous system of the lower limb: a review. Journal of Tissue Viability. 2002; 12(2): 58-65.