A leg pump, professionally known as a Sequential Compression Device (SCD) or Intermittent Pneumatic Compression (IPC) device, is a non-invasive medical tool. Its primary purpose is to prevent Deep Vein Thrombosis (DVT)—a condition where a blood clot forms in a deep vein, typically in the leg—in people with limited mobility. By applying external pressure, the device improves blood circulation and prevents the pooling of blood, a major factor in clot formation. SCDs are commonly used in hospitals for patients recovering from surgery or those confined to bed rest.
The Mechanism of Compression
The SCD operates using inflatable sleeves that wrap around the patient’s lower extremities and connect to an electronic pump. These sleeves have multiple air chambers that inflate and deflate in a specific, wave-like pattern. This sequential inflation begins at the ankle and moves upward toward the knee or thigh, creating a “milking” action on the veins.
This mechanical compression mimics the natural muscle contractions that occur during walking. By increasing the velocity of venous blood flow, the device directly combats venous stasis, or blood pooling, which leads to DVT formation. The rapid movement of blood discourages clot formation and ensures continuous return of blood to the heart. The pressure cycles also stimulate the release of natural anti-clotting agents, such as tissue plasminogen activator, from the lining of the blood vessels.
Standard Treatment Duration and Usage Frequency
The effectiveness of the SCD relies heavily on continuous use. For DVT prevention, the device should be worn for the majority of the day and night to maintain the protective effect. Medical guidance consistently recommends a daily usage requirement of at least 18 to 20 hours.
The device must be in place whenever the patient is in bed or sitting with limited movement. The sleeves are only removed for short periods, such as when the patient is bathing, walking, or receiving other medical treatments. Any interruption in the compression cycle increases the risk of blood stasis and clot formation, so the device must be quickly reapplied after removal.
The total duration of treatment is determined by the patient’s underlying risk factors and is highly individualized. For post-surgical patients, treatment continues until they are fully mobile and no longer considered at high risk for DVT, typically a few days or weeks. For patients with long-term immobility, treatment may extend for weeks or months, or until an alternative prophylaxis method is prescribed. The goal is to continue mechanical prophylaxis until the patient can walk and move independently, thereby restoring the body’s natural blood-pumping mechanism.
Proper Application and Safety Precautions
Correct application of the SCD sleeve is important to ensure both efficacy and patient safety. The appropriate sleeve size must be determined by measuring the leg’s circumference and length to guarantee a snug yet comfortable fit. A common test for proper fit is ensuring that two fingers can easily slide between the sleeve and the skin.
The tubing connecting the sleeves to the pump must be checked regularly to confirm it is not kinked, twisted, or trapped under the patient, which would impede the inflation cycle. The pump itself must also be functioning correctly, cycling through the inflation and deflation phases as intended. The skin underneath the sleeves requires regular assessment for irritation, blistering, or pressure sores, and the sleeves should be briefly removed at least once per shift for a thorough skin check.
The SCD is not appropriate for all patients, and several conditions contraindicate its use. The device should never be used on a limb where an active DVT or severe arterial insufficiency has been diagnosed, as the applied pressure could dislodge a clot or severely restrict blood flow. Situations requiring caution include unstable lower extremity fractures, recent skin grafts, or severe soft tissue injury in the area of compression.