PULMONARY EMBOLISM

PULMONARY EMBOLISM

  • Obstruction of the pulmonary artery or one of its branches by a thrombus originating from the venous system or the right side of the heart.

EMBOLUS

  • A clot or plug carried by the bloodstream to a smaller blood vessel, obstructing circulation.

CLASSIFICATION OF PE

1. Fat Embolism

  • Cholesterol or fatty substances that can clog arteries, especially after consumption of fatty foods.

2. Air Embolism

  • Air emboli usually originate from intravenous devices.

3. Amniotic Fluid Embolism

  • Results from amniotic fluid leaking into the arteries.

4. Septic Embolism

  • Originates from bacterial invasion of a thrombus from a distant infectious source blocking a blood vessel.

PATHOPHYSIOLOGY OF PE

  • General Overview:

    • Pulmonary thromboembolism is a complication of underlying venous thrombosis.

    • Thromboemboli travel through the right heart (RA → RV → LA → LV) to reach the lungs.

1. Obstruction

  • Effects:

    • Partial or complete obstruction leads to increased alveolar dead space (volume of air vented but not perfused).

2. Impairment

  • Impact:

    • Area receives little or no blood flow, severely impairing gas exchange.

3. Constriction

  • Contributing Factors:

    • Various substances from the clot and surrounding area cause blood vessel constriction, increasing pulmonary resistance.

4. Consequences

  • Result:

    • Increased pulmonary vascular resistance leads to higher pulmonary arterial pressure and increased workload on the right ventricle.

5. Failure

  • Outcome:

    • Excessive workload on the right ventricle may result in heart failure.

PREDISPOSING FACTORS OF PE

  1. Stasis and prolonged immobilization

  2. Concurrent phlebitis

  3. Heart failure and stroke

  4. Injury to vessel wall

  5. Coagulation disorders and hypercoagulable state

  6. Malignancy

  7. Advancing age, estrogen therapy, oral contraceptives

  8. Fractures of long bones

  9. Obesity

CLINICAL MANIFESTATIONS OF PE

1. Symptoms

  • Rapid onset of dyspnea, pleuritic chest pain, cough, syncope, delirium, apprehension, tachypnea.

2. Chest Pain

  • Accompanied by apprehension and a sense of impending doom, mainly when the pulmonary artery is severely obstructed.

3. Additional Symptoms

  • Includes tachycardia, rales, fever, hypotension, cyanosis, heart gallop, and loud pulmonic component of S2.

4. Signs Suggestive of DVT

  • Calf or thigh pain with edema, erythema, tenderness or palpable cord.

PREVENTION OF PE

1. Avoid Venous Stasis

  • Measures:

    • Active leg exercises, early ambulation, and anti-embolism stockings.

2. Sequential Compression Devices

  • Function:

    • Inflatable plastic sleeves for compression and relaxation of calf muscles.

3. Mechanical Prophylaxis

  • Classification:

    • Can be static or dynamic.

4. Graduated Compression Stockings

  • Mechanism:

    • Sequential air movement in the sleeve up the leg, followed by relaxation.

5. Anticoagulant Therapy

  • Application:

    • Prescribed for patients undergoing major elective abdominal or thoracic surgeries with adequate hemostasis.

COMPLICATIONS OF PE

1. Cardiogenic Shock

  • Description:

    • Acute condition resulting from the heart's inability to pump sufficient blood.

2. Right Ventricular Failure

  • Cause:

    • A sudden increase in pulmonary resistance raises the right ventricle workload.

3. Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

  • Outcome:

    • Abnormal enlargement of the right heart due to lung or pulmonary blood vessel disease.

DIAGNOSTIC EVALUATIONS

1. Thoracic Imaging

  • CT Scan:

    • Reveals recanalization, webs/flaps, partial filling defects with obtuse angles against the vessel wall.

2. Pulmonary Angiography

  • Considerations:

    • Not advised for pregnant patients or those with advanced renal failure; can show partial filling defects or complete occlusion.

3. D-Dimer Assay

  • Purpose:

    • Blood test for clotting problems.

    • Normal level: less than 500 ng/ml; elevated level: more than 500 ng/ml.

4. ABG Analysis

  • Findings:

    • Decreased PaO2 due to abnormal lung perfusion; indicates hypoxemia and hypocapnia.

5. Chest X-Ray

  • Observations:

    • Generally normal or may show wedge-shaped infiltrate.

MEDICAL MANAGEMENT

1. Anticoagulation Therapy

  • Medications:

    • Heparin and warfarin sodium; primary treatment for acute DVT and PE.

2. Thrombolytic Therapy

  • Examples:

    • Urokinase, streptokinase, alteplase.

SURGICAL MANAGEMENT

1. Embolectomy

  • Procedure:

    • Removal of the clot by a cardiovascular surgical team while the patient is on cardiopulmonary bypass.

2. Transverse Catheter Embolectomy

  • Technique:

    • Vacuum-cupped catheter introduced transvenously into the affected pulmonary artery.

3. Interruption of the Vena Cava

  • Purpose:

    • Prevents dislodged thrombi from entering the lungs while allowing blood flow.

4. Embolization

  • Description:

    • Procedure using particles (e.g., gelatin sponges or beads) to block a blood vessel.

NURSING INTERVENTIONS

1. Prevent Venous Stasis

  • Actions:

    • Encourage ambulation and leg exercises, both active and passive.

2. Monitor Thrombolytic Therapy

  • Monitoring through INR or PTT to ensure safety and efficacy.

3. Manage Pain

  • Approach:

    • Frequent repositioning to improve ventilation-perfusion ratio.

4. Manage Oxygen Therapy

  • Duty:

    • Assess hypoxemia signs and monitor pulse oximetry values.

5. Relieve Anxiety

  • Strategy:

    • Allow patients to discuss fears or concerns regarding their condition.