Deep Vein Thrombosis

DEEP VEIN THROMBOSIS

OBJECTIVES At the end of this presentation students should be able to • Define Deep Vein Thrombosis • State the incidence of Deep Vein Thrombosis • List the aetiology and risk factors of DVT • Describe the pathophysiology of DVT • List the clinical manifestations of DVT • State the diagnostic assessment of DVT • Discuss the medical, surgical and nursing management

DEFINITION • DVT occurs when a blood clot forms in a deep vein. • It most commonly happens in the deep veins of the lower leg (calf), and can spread up to the deep veins in the thigh. • Rarely, it can develop in other deep veins, for example in the arm •

INCIDENCE • DVT occur in about 1 per 1000 persons per year. • Approximately 350,000 to 600,000 Americans each year suffer from DVT and 1 in every 100 people who develops DVT dies. • More common in people over the age of 80 (up to one in 500). •

AETIOLOGY IMMOBILITY: this causes blood flow in the veins to be slow. Slow flowing blood is more likely to clot HYPERCOAGULABILITY (coagulation of blood faster than usual) TRAUMA to the vein: increases the risk of a blood clot forming

RISK FACTORS • Sitting for long periods of time, such as when driving or flying • Prolonged bed rest, during a long hospital stay, or paralysis (from spinal cord injury) (causes calf muscles not to contract, slows blood circulation thus forming clots) • Inheriting a blood-clotting disorder • Injury or surgery (can slow blood flow thus increasing the risk of blood clots) • Pregnancy (increases the pressure in the veins in the pelvis and legs)

RISK FACTORS • Cancer (some cancers increase clotting factors along with some forms of cancer treatment increase the risk of blood clots) • Heart failure (affects the pumping mechanism of the heart increases the chance that blood will pool and clot) • Smoking (affects blood clotting and circulation) • Birth control pills or hormone replacement therapy (increase the blood's ability to clot) • A history of deep vein thrombosis or pulmonary embolism.

RISK FACTORS • A family history of DVT or PE. • Being overweight or obese (increases the pressure in the veins in your pelvis and legs) • Increasing age (people older than 40) • Polycythemia (increased number of red blood cells)

PATHOPHYSIOLOGY VIRCHOW’S TRIAD • Stasis of blood • Vessel damage • Increased blood coagulability Vessel trauma stimulates the clotting cascade. • Platelets aggregate at the site particularly when venous stasis present • Platelets and fibrin form the initial clot

PATHOPHYSIOLOGY cont’d • RBC are trapped in the fibrin meshwork • The thrombus propagates in the direction of the blood flow • Inflammation is triggered, causing tenderness, swelling, and erythema • Pieces of thrombus may break loose and travel through circulation- emboli • Fibroblasts eventually invade the thrombus, scarring vein wall and destroying valves. • Although the patency may be restored valve damage is permanent, affecting directional flow

PATHOPHYSIOLOGY

Clinical Manifestations • Tenderness in the calf (this is one of the most important signs) • Swelling of the leg • Increased warmth of the leg • Redness in the leg • Bluish skin discoloration • Discomfort when the foot is pulled upward

Diagnostic Assessment • Venous duplex / color duplex ultrasoundthis non-invasive test allows for visualization of the thrombus. Most effective in the detection of thrombus in the lower extremities. • Impedance plethysmography – measures changes in calf volume corresponding to changes in blood volume brought about by temporary venous occlusion with a highpneumatic cuff.

Diagnostic Assessment cont’d • Radioactive fibrinogen - is administered intravenously. Images are taken through nuclear scanning at 12-24 hours, the radioactive fibrinogen will be concentrated at the area of clot formation. • Venography- intravenous injection of a radiocontrast agent. The vascular tree is visualized and obstruction is identified.

Diagnostic Assessment cont’d • Coagulation profiles- partial thrombin time, international normalized ratio, circulating fibrin, monometer complexes, fibrinopeptide A, serum fibrin, D-dimer, antithrombin III levels.

MANAGEMENT The goals of DVT treatment are:  to stop blood clot from getting any bigger  to prevent the clot from breaking loose and causing a PE  to prevent DVT from occurring again. • Deep vein thrombosis treatment options include: Blood thinners, Clot busters, Filters & Compression Stockings

MANAGEMENT MEDICATIO NS  Blood thinners (anticoagulants) such as

HEPARIN and WARFARIN decrease blood's ability to clot prevent clots from getting bigger reduce the risk of additional clots. • Typically, heparin injections are given for a few days. Treatment may be followed with warfarin (orally) for 3 mths or longer.

MANAGEMENT • The use of heparin and warfarin must be closely monitored as they can increased risk of bleeding. • To monitor the effects of blood thinners, blood tests are done to check how long it takes the blood to clot. • Pregnant women should not take warfarin.

MANAGEMENT  Clotbusters (thrombolytics) such as tissue plasminogen activator (tPA) or Steptokinase are given by IV to break up blood clots. These drugs can cause serious bleeding and are used only in life-threatening situations.  Filters (umbrellas)are used when medications cannot be taken to thin the blood, it may be inserted into the vena cava and prevents emboli from lodging in the lungs.

MEDICAL MANAGEMENT

MEDICAL MANAGEMENT • Rest: in DVT and limited mobilization is required to prevent dislodgement of clot leading to pulmonary embolism. • Elevation of the affected part: this is to promote adequate venous return and prevent stasis.

MANAGEMENT  Compression stockings helps prevent swelling associated with DVT by applying pressure thus reduce the chances that the blood will pool and clot . The stockings are worn on the leg from the foot to the level of the knee and should be worn for at least a year if possible.

SURGICAL MANAGEMENT • Deep vein thrombosis is usually treated with conservative measures and anticoagulant. In some cases however surgery may be required to remove thrombus. • Venous thrombectomy: done when thrombi lodge into femoral vein and their removal is necessary. • When DVT is recurrent and anticoagulant therapy is contraindicated a Greenfield filter or a venal caval filter may be inserted into the inferior vena cava to trap the clots.

Surgical management • Ligation or external clips: if filters are not effective in preventing pulmonary emboli or becomes blocked ligation is done or an external clip (Adam DeWeese clip) may be inserted on the inferior vena cava. This can be done by means of an abdominal laparatomy

NURSING MANAGEMENT ASSESSMENT Health history: • C/o calf pain, duration characteristics and the effect of walking on the pain • Hx of venous thrombosis or other clotting disorders • Current medication Physical examination: • Inspect affected extremity for redness and edema • Palpate for tenderness, warmth and cordlike structures • Body temperature

NURSING MANAGEMENT Rest comfort and activity: Altered comfort pain: r/t inflammatory process 20 DVT as evidenced by patients verbalization INTERVENTIONS • Assess pain location, characteristic and level. For baseline data and to plan appropriate nursing interventions • Monitor for increasing pain, location or characteristics and report to the physician promptly – increasing pain may indicate extension if thrombosis sudden chest pain may indicate pulmonary embolism

NURSING MANAGEMENT • Apply warm moist heat to the affected extremity at least four times daily. Moist heat penetrate tissues to a greater depth. Warmth promotes vasodilation which reduces resistance within the affected vessels, reducing pain. • Elevate the affected limb about 150 to 200above the level of the heart. To promote venous return which reduces edema thus reducing pain • Maintain bed rest as ordered. Using muscles during walking exacerbate the inflammatory process and increases edema which increases venous compression and pain

NURSING MANAGEMENT • Administer NSAID’s for leg pain as ordered eg. Voltaren. To inhibit prostaglandin synthesis by decreasing enzyme needed for biosynthesis, thus decreasing pain. • Encourage diversional activities such as watching television or guided imagery. To augment analgesics and improve pain tolerance.

NURSING MANAGEMENT Oxygen Ineffective tissue perfusion: peripheral r/t obstruction of blood flow and vessel spasm 20 DVT aeb cyanosis of affected extremity • Assess skin of the affected leg which includes skin integrity and colour. Reassess every 8 hrs. To rapidly detect early signs and plan for appropriate nursing intervention. • Monitor peripheral pulses and capillary refill time at least every 4 hrs, and report changes immediately. Weak or absent pulses and impaired capillary refill may indicate extension of the thrombus.

NURSING MANAGEMENT levate extremities at all times, keeping knees slightly flexed and legs above the level of the heart. To promote venous return and reduce peripheral edema ncourage patient to wear an antiembolic stocking. To exert pressure on the extremity and promote venous return emove antiembolic stocking for 30-60 mins during daily hygienic. To assess the underlying tissue and

NURSING MANAGEMENT nsure adequate hydration by increasing oral fluids. To prevent dehydration as increased blood viscosity and decreased cardiac output contribute to thrombus formation

se egg crate mattress on the bed as needed. To distribute weight evenly, preventing excess pressure on the affected tissues

ncourage frequent position changes, at least every 2 hrs. This reduce pressure on bony prominences and edematous tissues, reducing the risk of tissue breakdown.

NURSING MANAGEMENT SAFETY AND SECURITY Risk for Complication: Pulmonary Embolism r/t dislodgement of thrombus 2 to DVT • Assess vital signs esp. respiration and pulse. To detect early signs of complication for early intervention. • Promote bed rest and limited mobilization. To prevent dislodgement of clots. • Encourage the use of support stocking. To prevent stasis of blood, hence reducing clot formation. • Administer thrombolytic agents, eg. Streptokinase. To dissolve clots and decrease the risk of PE

NURSING MANAGEMENT • Administer antispasmodic agents ie. Baclofen. To prevent vascular spasm that may dislodge clot and cause PE. • Prepare patient for surgical insertion of filters, if indicated. Filters are placed in the inferior vena cava to trap clot so they do not enter the lungs causing PE.

NURSING MANAGEMENT Safety and security Risk for complication: haemorrhage r/t anticoagulant therapy • Assess for evidence of bleeding such as petechiae, bruising, bleeding gums etc. For baseline and to plan appropriate nursing interventions

NURSING MANAGEMENT

onitor lab results such as INR, APTT, Hb and haematocrit levels. Report values outside the desired range. Value within normal rage prevent further clot development while a fall may indicate undetected bleeding.

onitor vital signs q4h. Rapid weak thready pulse and low blood pressure may be

NURSING MANAGEMENT eep Protamine sulfate available. To treat excessive bleeding

ncourage patient to use an electric razor for shaving and a soft tooth brush for brushing teeth. To decrease the risk of bruising and bleeding

void invasive procedures as much as possible such as rectal temperature, vaginal douches or tampons, urinary catheterization. Parenteral injections etc. Invasive procedure can cause tissue trauma and bleeding

PREVENTION xercise the legs regularly – take a brisk 30-minute walk every day aintain a weight that's appropriate for your height void sitting or lying in bed for long periods of time without moving the legs lthough the added risk of developing a DVT caused by traveling appears to be low, it can be reduced even further by exercising the legs at least once every hour during long-distance travel

PREVENTION • Keep the legs uncrossed • Keep hydrated by drinking normally (urine should be no darker than a pale yellow). Avoid alcohol to prevent dehydration • Wear graduated compression stockings. This is particularly important for travelers who have other risk factors for DVT

COMPLICATIONS The primary complication to be concerned with is a Pulmonary embolism. It occurs when an artery in your lung becomes blocked by a blood clot (thrombus) that travels to your lungs from another part of your body, usually your leg

COMPLICATIONS

COMPLICATIONS Postphlebitic syndrome also called postthrombotic syndrome. • Occurs in 15% of patients DVT. • It presents with leg edema, pain, nocturnal cramping, venous claudication, skin pigmentation, dermatitis and ulceration (usually on the medial aspect of the lower leg)

REFERENCE • http://www.webmd.com/heart-disease/tc/deep-vein-thrombosis-whatincreases-your-risk • http://www.webmd.com/heart-disease/tc/deep-vein-thrombosis-topicoverview • http://www.mayoclinic.com/health/deep-vein-thrombosis/DS01005 • http://en.wikipedia.org/wiki/Deep_vein_thrombosis • http://www.medicinenet.com/deep_vein_thrombosis/article.htm