Deep Vein Thrombosis Nursing Care Management and Study Guide

A clot in a deep vein, usually in the leg, is dangerous for one reason: it can break loose, travel, and lodge in the lungs. Your job on the floor is to catch it early, prevent extension, and keep the patient from throwing a pulmonary embolus. The signs are nonspecific, so do not wait for a textbook picture before you act.

Deep vein thrombosis (DVT) is part of venous thromboembolism. A thrombus forms in one or more deep veins, most often in the legs. It can cause leg pain or swelling, or it can be silent. Sometimes the first sign of DVT is the PE itself.

Pathophysiology

The exact trigger is not always clear, but the mechanics are. Venous stasis sets it up: reduced blood flow, dilated veins, and reduced skeletal muscle contraction. Damage to the intimal lining gives the clot a place to anchor, and thrombus formation often rides along with phlebitis (inflammation of the vein wall).

Venous thrombi are platelet aggregates attached to the vein wall with a tail of fibrin, white cells, and red cells. That tail can propagate downstream as new layers form. Fragmentation happens when the clot dissolves on its own or when venous pressure rises, and that is the moment a piece can embolize. After an acute episode, the vessel usually recanalizes and the lumen reopens.

Statistics and Incidences

Incidence climbs with acuity: 10% to 20% in general medical patients, 20% to 50% in stroke patients, and up to 80% in critically ill patients. As many as 30% of patients hospitalized with DVT go on to develop long-term post-thrombotic complications.

Causes

The exact cause is unknown, but several factors push the risk up. Direct trauma from a fracture or dislocation, venous disease, or chemical irritation from IV medications and solutions damages the vessel. Increased blood coagulability shows up most often when anticoagulants are abruptly withdrawn, and oral contraceptives drive hypercoagulability too. Normal pregnancy raises clotting factors that may not return to baseline until longer than 8 weeks postpartum. Repetitive motion irritates the vessel wall, triggering inflammation and thrombosis.

Clinical Manifestations

The signs are nonspecific, which is the main problem with recognizing DVT. Watch for edema and swelling of the extremity as venous outflow is blocked. In phlegmasia cerulea dolens (massive iliofemoral venous thrombosis) the entire extremity becomes massively swollen, tense, painful, and cool to the touch. Tenderness usually shows up later, produced by inflammation of the vein wall, and you can detect it by gently palpating the affected leg. In some patients the first indication of DVT is a pulmonary embolus.

Prevention

Identify high-risk patients and start prevention without delay. Graduated compression stockings prevent dislodgement of the thrombus. Intermittent pneumatic compression devices push blood velocity beyond what stockings alone produce. Encourage early mobilization and leg exercises to keep blood moving.

Complications

Most complications come from the treatment. The principal complication of anticoagulant therapy is spontaneous bleeding, detectable on microscopic examination of urine. Heparin-induced thrombocytopenia is a sudden drop in platelet count by at least 30% of baseline. Because oral anticoagulants interact with many medications and herbal and nutritional supplements, monitor the patient's full medication schedule closely.

Assessment and Diagnostic Findings

Doppler ultrasound: position the transducer tip at a 45- to 60-degree angle over the expected location of the artery and angle it slowly to identify arterial blood flow. Computed tomography provides cross-sectional images of soft tissue and shows volume changes in the extremity and the compartment where they occur.

Medical Management

The goals are to keep the thrombus from growing and fragmenting, prevent recurrent thromboemboli, and prevent post-thrombotic syndrome. Endovascular management is used when anticoagulant or thrombolytic therapy is contraindicated, when the danger of PE is extreme, or when venous drainage is so compromised that permanent damage to the extremity is likely. A vena cava filter may be placed at the time of thrombectomy to trap late emboli and prevent pulmonary emboli.

Pharmacologic Therapy

The point is to prevent or reduce clotting within the vascular system. Unfractionated heparin is given subcutaneously to prevent DVT, or by intermittent or continuous IV infusion for 5 days to prevent extension of a thrombus and formation of new ones. Subcutaneous low-molecular-weight heparins (LMWHs) such as dalteparin and enoxaparin are effective in some cases and prevent both extension and new thrombi. Warfarin, a vitamin K antagonist, is indicated for extended anticoagulant therapy. Fondaparinux selectively inhibits factor Xa. Catheter-directed thrombolytic therapy, unlike the heparins, lyses and dissolves thrombi in at least 50% of patients.

Nursing Management

Nursing Assessment

If a patient presents with signs and symptoms of DVT, take a general medical history and do a physical exam to rule out other causes. Because clinical features are unreliable, use Well's diagnostic algorithm, which classifies patients as high, intermediate, or low probability of DVT.

Nursing Diagnosis

Based on the assessment data, the major nursing diagnoses are: ineffective tissue perfusion related to interruption of venous blood flow; impaired comfort related to vascular inflammation and irritation; risk for impaired physical mobility related to discomfort and safety precautions; and deficient knowledge regarding the pathophysiology of the condition related to lack of information and misinterpretation.

Nursing Care Planning & Goals

The patient should demonstrate increased perfusion as individually appropriate, verbalize understanding of the condition, therapy, regimen, medication side effects, and when to contact the provider, engage in behaviors or lifestyle changes that increase ease, verbalize a sense of comfort, maintain position of function and skin integrity (no contractures, footdrop, or decubitus), and maintain or increase strength and function of the affected or compensatory body part.

Nursing Interventions

Provide comfort. Elevate the affected extremity, use graduated compression stockings, apply warmth, and ambulate the patient to remove or reduce discomfort.

Use compression therapy. Graduated compression stockings reduce the caliber of the superficial leg veins and increase flow in the deep veins. External compression wraps are short-stretch elastic wraps applied from the toes to the knees in a 50% spiral overlap. Intermittent pneumatic compression devices raise blood velocity beyond what the stockings produce.

Position and exercise. On bed rest, elevate the feet and lower legs periodically above heart level, and perform active and passive leg exercises to increase venous flow.

Evaluation

Confirm the planned goals were met: increased perfusion, verbalized understanding of the condition and medication regimen, engagement in ease-promoting behaviors, a verbalized sense of comfort, maintained position of function and skin integrity, and maintained or increased strength and function of the affected or compensatory body part.

Discharge and Home Care Guidelines

Teach the prescribed anticoagulant: its purpose and the need to take the correct amount at the specific times prescribed. The patient should know that periodic blood tests are needed to decide whether the medication or dosage should change. A person who will not stop drinking alcohol should not receive anticoagulants, because chronic alcohol intake decreases their effectiveness. Explain the importance of elevating the legs and exercising adequately.

Documentation Guidelines

Document the nature, extent, and duration of the problem and its effect on independence and lifestyle; characteristics of discomfort; pulses and BP; factors affecting the sense of discomfort; medication use and nonpharmacologic measures; the plan of care; the teaching plan; the response to interventions, teaching, and actions performed; attainment or progress toward desired outcomes; and any modifications to the plan of care.