Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE): Nursing Study Guide

Deep vein thrombosis (DVT) and pulmonary embolism (PE) together make up venous thromboembolism (VTE) — one of the highest-yield emergency topics on the NCLEX. This guide walks through pathophysiology, risk factors, diagnostics, treatment, and nursing priorities for both conditions, plus common test traps.

What Is DVT?

• Deep vein thrombosis is a blood clot that forms in the deep veins, most commonly in the lower extremities.
• DVT is part of venous thromboembolism (VTE), along with pulmonary embolism.
• Prompt diagnosis and treatment are essential to prevent life-threatening complications.

DVT Risk Factors (Virchow's Triad)

• Venous stasis: immobility, prolonged travel, bed rest, recent surgery, obesity.
• Vascular injury: trauma, surgery, fractures, IV catheters, previous DVT.
• Hypercoagulability: cancer, pregnancy, oral contraceptives, inherited clotting disorders, smoking.

DVT Clinical Presentation

• Unilateral leg pain, swelling, and warmth are the most common symptoms.
• The affected leg may appear red or discolored compared with the unaffected side.
• Patients may report a feeling of heaviness or fullness in the calf or thigh.
• A low-grade fever may be present.
• Homan's sign (calf pain with foot dorsiflexion) is NOT reliable for diagnosis.

DVT Diagnostic Approach

Wells Score for DVT

• Score ≥ 2: DVT likely → proceed directly to ultrasound.
• Score ≤ 1: DVT unlikely → check D-dimer first.

D-Dimer Testing

• A negative D-dimer (<0.50 µg/mL) rules out DVT in low-risk patients.
• A positive D-dimer requires ultrasound confirmation.
• D-dimer is sensitive but not specific — it can be elevated in many conditions.

Imaging

• Venous duplex ultrasound is the first-line imaging method for DVT.
• It is noninvasive, highly accurate, and visualizes clot location.

DVT Treatment

Anticoagulation is the cornerstone of treatment. Note: anticoagulation does NOT dissolve clots — it prevents extension and allows the body to dissolve them.

Treatment Duration

• Provoked DVT (surgery, trauma): 3 months.
• Unprovoked DVT: at least 3 months; often extended.
• Cancer-associated DVT: 3–6 months minimum; DOACs preferred.
• Recurrent DVT or high-risk thrombophilia: lifetime treatment.

DVT Nursing Care

• Measure and compare bilateral calf circumferences daily.
• Do NOT massage the affected leg — this can dislodge the clot.
• Elevate the affected extremity above heart level to reduce edema.
• Apply warm compresses for comfort.
• Administer anticoagulants and monitor for bleeding.
• Apply compression stockings to prevent post-thrombotic syndrome.
• Encourage ambulation once anticoagulation is therapeutic.

DVT Complications

What Is Pulmonary Embolism?

• PE occurs when a DVT dislodges and travels to the lungs, blocking a pulmonary artery.
• Causes ventilation–perfusion mismatch, hypoxemia, and increased pulmonary vascular resistance.
• Large emboli can cause right ventricular failure and hemodynamic collapse.
• PE is a life-threatening emergency with high mortality if not promptly treated.

PE Clinical Presentation

Symptoms

• Sudden-onset dyspnea is the most common symptom.
• Pleuritic chest pain (sharp pain with breathing) in about 50% of patients.
• Cough, hemoptysis, anxiety, sense of doom.
• Syncope can occur with massive PE.
• Unilateral leg swelling from the source DVT.

Physical Findings

• Tachypnea, tachycardia, hypoxemia are common.
• Decreased breath sounds, crackles, or wheezes may be heard.
• Signs of right heart failure (JVD, hepatomegaly, edema) in massive PE.

PE Risk Stratification

PE Diagnostic Approach

Wells Score for PE

• Score > 4: PE likely → proceed directly to CTPA.
• Score ≤ 4: PE unlikely → check D-dimer first.

D-Dimer Testing

• Negative D-dimer rules out PE in low-risk patients.
• Positive D-dimer requires CTPA confirmation.

Imaging

• CT pulmonary angiography (CTPA) is the preferred study.
• V/Q scan is an alternative if CTPA is contraindicated.

PE Treatment

Stable PE (Low- and Intermediate-Risk)

• Anticoagulation is the mainstay.
• Same options and durations as DVT.

Massive PE (High-Risk with Hemodynamic Instability)

First actions:

• Assess ABCs, give high-flow oxygen, establish IV access.
• Give cautious IV fluids (≤500 mL bolus) — avoid volume overload.
• Start vasopressors (norepinephrine) if needed.

Reperfusion therapy:

• Thrombolytics (tPA, alteplase) are life-saving in massive PE.
• If thrombolytics are contraindicated or fail → embolectomy.

Contraindications to thrombolytics: active bleeding, recent stroke, recent major surgery, severe hypertension.

PE Nursing Care

• Monitor vital signs continuously (BP, HR, RR, SpO₂).
• Assess chest pain and respiratory status.
• Watch for signs of right heart failure: JVD, edema.
• Administer oxygen to maintain SpO₂ > 92%.
• Position patient in semi-Fowler's to high-Fowler's.
• Administer anticoagulants; monitor for bleeding.
• With thrombolytics, monitor closely for bleeding.

Patient Teaching for VTE

• Take anticoagulants exactly as prescribed; never skip doses.
• Report signs of bleeding: dark stools, coffee-ground vomit, unusual bruising.
• Use a soft toothbrush and electric razor.
• Wear medical alert identification.
• Avoid prolonged sitting or standing.
• Move legs frequently on long trips and stay well hydrated.
• Wear compression stockings as prescribed.
• Report new leg swelling, pain, redness, or sudden shortness of breath.

Common NCLEX Traps

• Never massage a DVT leg — can dislodge the clot and cause PE.
• Homan's sign is not reliable for DVT diagnosis.
• D-dimer is sensitive but not specific; a positive result requires imaging.
• Wells score determines the testing path, not the diagnosis itself.
• Anticoagulation does not dissolve clots — it prevents extension.
• DOACs are first-line for most patients, including many with cancer.
• Thrombolytics are only for massive/unstable PE.
• Warfarin requires a heparin bridge until INR is therapeutic.
• In pregnancy, use LMWH — DOACs are contraindicated.

Key Takeaways

• DVT presents with unilateral leg swelling, pain, and warmth; use Wells score to decide between ultrasound and D-dimer.
• Anticoagulation is the cornerstone of DVT/PE treatment — DOACs are first-line for most patients, LMWH preferred in pregnancy and cancer.
• Never massage a DVT leg; elevate the extremity and apply compression stockings.
• PE = sudden dyspnea, pleuritic chest pain, hypoxia; diagnose with Wells score → CTPA or D-dimer.
• Massive PE (SBP <90 mmHg) requires thrombolytics or embolectomy; stable PE is treated with anticoagulation.
• Teach patients bleeding precautions, medication adherence, and to report new leg swelling or sudden shortness of breath.