DUAL PURPOSE Using anti-embolism stockings and sequential compression devices in combination addresses the key factors for DVT prevention.

The stakes are high when it comes to preventing deep vein thrombosis and pulmonary emboli. Between 300,000 and 600,000 people suffer DVT and PE each year, with 60,000 to 100,000 ultimately dying from the complications. When it's not fatal, DVT can cause post-op morbidity, prolonged hospitalization and increased healthcare costs. An essential part of caring for surgical patients is to understand your role and responsibilities in preventing clots from forming.

Know the risks
DVT commonly occurs when blood flow changes, which could cause clots to form in deep veins, often in the calf or thigh and less commonly in the chest or arm. Pulmonary emboli develop when clots break free from veins and travel to the lungs. The condition can prove fatal within minutes or hours. Who's at risk? Anyone who undergoes surgery, because injuries to vessels when surgeons operate and changes in blood chemistry caused by dehydration or general anesthetics increase the likelihood of clots forming. That said, more invasive procedures in the abdomen or lower extremities put patients at increased risk. Other factors that heighten DVT possibilities include advanced age, obesity, recent physical trauma, varicose veins, personal or family history of circulation problems, surgeries lasting longer than 45 minutes, and hip or knee replacement surgery.

Pick the prophylaxis
Muscles in prone, anesthetized patients aren't working as they normally would; even sleeping individuals move slightly every few minutes to keep blood flowing properly. Two effective preventative measures against DVT:

• Sequential compression devices. SCDs combat venous stasis and coagulation changes by squeezing legs to stimulate muscles and move blood through the veins.

• Anti-embolism stockings. Stockings protect against venous stasis and vessel wall damage by keeping leg muscles tight and firm, which reduces pooling of blood in the veins.

Using both in combination therefore protects patients against all 3 risk factors of DVT. The stimulation and constriction combine to regulate the blood's chemistry and break down any blood clots that might form.

We put SCDs on all patients, except those undergoing quick eye cases, although some surgeons write orders to add stockings to the prevention effort. Compression devices and stockings should be applied in the pre-op holding area and kept on patients throughout surgery (when possible) and during their recoveries. Stockings come in thigh-length and knee-length options. According to the literature, knee-length options work just as effectively as those that stretch to the patient's thigh. Because knee-high stockings are more comfortable for patients, they're likely the preferred option.

Anticoagulants such as aspirin, warfarin and low-molecular-weight heparin are effective prevention options for patients who present with known DVT risk factors. Administer doses 1 hour before surgery and continue administration post-op for these individuals.

Ensure the proper fit
Compression sleeves are made for the arms, but their use is rare. Applying stockings to lower extremities makes more practical sense in most cases (as long as they don't interfere with the operative site) because during surgery, blood pressure cuffs and IVs are in place on and in the arms.

The main issue when using compression stockings is to match the correct size to the patient. Stockings that don't fit properly throughout the duration of their use might roll down the patient's legs, causing nerve or muscle injury or prompting the patient to remove the stockings because the fit is uncomfortable.

Nurses tend to approximate the size of the leg and don't take the time to properly measure the calf and thigh. That's not sound practice. Take the time to determine the exact circumference and leg length in order to match the measurement with the recommended size (in inches) on the stockings' package. Order two different stockings if the right and left legs measure differently. Also continually measure the patients' legs throughout their stays because swelling may necessitate a change in stocking size. Finally, ensure stockings fit properly around the patients' feet; failing to do so could cause harmful constriction around the toes.

Understand the importance of managing patients after DVT preventative measures are started. For example, constantly assess the skin under SCDs or compression stockings to ensure pressure injuries have not occurred. It may sound like basic advice, but make sure SCDs are activated and remain running throughout their hospital stays.

Stress the importance to patients
Be sure to educate patients on why DVT prevention matters and why they're attached to compression devices and wearing anti-embolism stockings. Recovering patients are sometimes unhooked from the devices or have their stockings removed in order to ambulate following surgery, and don't understand the importance of reapplying the prophylaxis measures when they return to their beds. Others might forgo SCDs because the power unit is noisy or ignore the stockings because they're hot or uncomfortable. None of those factors are acceptable reasons for sidestepping DVT prevention, and that's something patients need to clearly understand.

Also emphasize that DVT risks remain even after patients are discharged to home, especially following outpatient procedures. Ensure patients watch for swelling or redness in extremities, particularly along the legs or around the ankles or feet. Shortness of breath and chest pains are indicators that clots have progressed to pulmonary emboli, and necessitate an immediate call to the surgeon and visit to the local emergency room.