Pulmonary Embolism Study Notes

Pulmonary Embolism Overview

  • Definition: Pulmonary Embolism (PE) is an obstruction of blood flow in part of the pulmonary vascular system, usually caused by an embolus, which can consist of blood, fat, air bubble, or bone marrow.

  • Thromboembolism: The most common type of PE is thromboembolism, which originates from a thrombus (blood clot) that travels to the lungs.

  • Prevention: Emphasized as crucial in managing PE, as it often leads to serious complications such as death.

Causes and Risk Factors for PE

Etiology

  • Stasis of blood flow: Can occur due to immobility (e.g., prolonged sitting on flights).

  • Vessel wall damage: Increases susceptibility to clot formation.

  • Altered blood coagulation: Conditions that affect blood clotting mechanisms.

  • Prolonged immobility: Associated with travel or bed rest due to illness.

  • Trauma: Physical injury can lead to clot formation.

Continued Risk Factors

  • Surgery: Especially orthopedic or any major surgery that requires immobilization.

  • Myocardial Infarction (MI) and heart failure: Contributes significantly to thromboembolic events.

  • Obesity: Increased body mass index can increase risk factors associated with stasis and coagulation.

  • Advanced age: The risk of PE increases with age due to various physiological factors.

  • Hormonal therapies: Oral contraceptives and estrogen therapy are linked to increased clotting risk due to elevated estrogen levels in the bloodstream.

  • Pregnancy and childbirth: Physiological changes during pregnancy contribute to increased clot formation.

Hormonal Contraception and Clotting Risk

  • Mechanism: Estrogen increases the blood's ability to clot. Women taking estrogen-containing contraceptives have a higher risk of developing blood clots, with approximately 0.3% to 1% chance over ten years while on the pill.

  • Safer Alternatives: Non-hormonal methods (e.g., Paragard IUD, condoms, diaphragm) or Progestin-only contraceptives (e.g., Mirena IUD) present lower clotting risks.

Clinical Manifestations of PE

Respiratory Symptoms

  • Dyspnea: Shortness of breath is a hallmark sign.

  • Sharp Chest Pain: Often sudden and can be mistaken for a heart attack.

  • Tachypnea: Increased breathing rate, often observed.

  • Hypoxia: Low levels of oxygen in the blood can occur.

Cardiac Symptoms

  • Tachycardia: Increased heart rate, may be indicative of compensatory mechanisms in response to decreased oxygenation.

  • Hemoptysis: The coughing up of blood can be a concerning symptom.

Other Symptoms

  • Distended neck veins: Indicative of right heart strain or overload.

  • Low-grade fever: Often observed in pulmonary congestion.

  • Flu-like symptoms: Occasionally present in patients with PE.

Diagnostic Tests for PE

  • Chest CT with contrast: Primary imaging modality for visualizing pulmonary emboli.

  • Lung scans: Ventilation-perfusion scans used to assess blood flow.

  • Chest X-ray (CXR): Utilized to exclude other pulmonary conditions.

  • Arterial Blood Gas (ABG): Determines oxygenation and acid-base status.

  • Coagulation Studies: Important for assessing clotting ability and planning anticoagulation therapy.

  • Wells Criteria/Geneva Score: Clinical scoring systems that assist in the probability assessment of PE; can help guide diagnostic testing.

Assessments for Patients with PE

  • Health History Assessment: Includes patient interviews regarding symptoms, risk factors, and medical history.

  • Physical Examination: Monitoring level of consciousness, vital signs, respiratory rate, and oxygen saturation.

Nursing Diagnosis

  • Impaired Gas Exchange: Interventions necessary to improve oxygenation.

  • Decreased Cardiac Output: Often a consequence of hypoxemia and increased workload on the heart.

  • Acute Pain: Addressing the patient’s discomfort from chest pain.

  • Anxiety: Many patients experience heightened anxiety associated with breathing difficulties or fear of death.

Nursing Interventions for PE

  • Oxygenation Promotion: Ensure patients receive supplemental oxygen as needed, to maintain adequate gas exchange.

  • Blood Pressure Preservation: Monitoring and managing organ function through blood pressure maintenance.

  • Thrombus Formation Prevention: Educating patients on mobility and anticoagulation therapy.

  • Monitoring Therapeutics: Regular assessment of thrombolytic or anticoagulant therapy effectiveness and side effects.

  • Pain Management: Administer pain medications when necessary.

Thrombolytic Agents

  • Available Agents:

    • Streptokinase

    • Alteplase

    • Reteplase

    • Tenecteplase

    • Urokinase

    • Anistreplase (APSAC)

Patient Education for PE

  • Prevention Awareness: Educating patients on signs and symptoms to report immediately (e.g., sudden chest pain, dyspnea).

  • Avoiding Injury: Advising against activities that increase injury risk due to potential bleeding while on anticoagulants.

  • Medication Knowledge: Importance of not taking over-the-counter medications without physician approval.

Additional Education Points

  • Compression Devices: Use of TEDS, SCDs, or compression stockings to enhance venous return.

  • Fluid Intake: Encourage ample hydration to avoid blood viscosity increase.

  • Activity Recommendations: Education about avoiding prolonged sitting and crossing legs, especially during travel.

Pharmacologic Therapy for PE

  • Anticoagulant Therapy: Standard treatment protocol.

    • Heparin: Contains bolus doses followed by a continuous infusion.

    • Lovenox (enoxaparin): Administered via injection.

    • Coumadin (warfarin): Typically started 5 to 7 days before discontinuation of heparin.

    • Direct Oral Anticoagulants (DOACs): Include dabigatran (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban (Savaysa), and betrixaban (Bevyxxa) for thrombosis prevention.

Other Treatments

  • Arterial Embolectomy: A procedure reserved for critical cases involving severe emboli.

    • Procedure Description: A Fogarty catheter is introduced into the occluded artery, typically through a femoral artery access. The thrombus is then extracted, and a balloon may be inflated to aid in clearing the blocked area.

Educational Session on Pulmonary Embolism

  • Understanding Embolism: An embolism is any substance that moves from one place to another and blocks blood flow. Types include:

    • Air embolism: From intravenous lines.

    • Fat embolism: From fractures.

    • Amniotic fluid embolism: From pregnancy.

    • Foreign body embolism: Material not naturally present.

  • Thromboembolism: Describes blood clots that originate from Deep Vein Thrombosis (DVT).

Pathophysiology of PE

  • Blood clot detaches from DVT and travels through the inferior vena cava to the heart.

  • If small enough, it usually passes through the heart but can become lodged in pulmonary vessels.

  • Potentially severe outcomes can include heart attacks or strokes if sufficiently large.

Risk Factors Summary

  • Immobility: Involved in long travel without movement.

  • Medical Conditions: Such as diabetes, cancer, obesity, surgeries, and heart failure.

  • Demographics: Typically affects elder patients; rare in children.

  • Lifestyle Factors: Smoking as a significant risk factor.

  • Hormonal Contraception Risks: Increased risk with combined oral contraceptives containing estrogen.

Clinical Presentation of PE

  • Chest Pain: Typically pleuritic rather than crushing, differing from heart attack pain.

  • Respiratory Symptoms: Include dyspnea, tachycardia, and hemoptysis.

  • Other Indicators: Anxiety, potential hyperventilation, and temporary hypertension; severe cases may show heart failure symptoms, abnormal ECG changes, and cardiovascular collapse.

Diagnostic Testing Methods for PE

  • D-dimer: Blood test used to evaluate hypercoagulability; a negative result makes PE less likely.

  • CTA (CT Angiogram): The primary imaging test for viewing pulmonary vessels and clots.

  • VQ scan: A nuclear medicine test using radioactive gas to assess ventilation and perfusion in the lungs.

  • Chest X-ray: Used for ruling out other common conditions such as pneumonia and fluid accumulation.

  • Coagulation Studies: PT/PTT tests should be done before commencing anticoagulation treatment.

Treatment Approaches for PE

  • Standard Anticoagulation: The most prevalent treatment method for small to moderate-sized PEs.

  • Thrombolytics: Reserved for large, life-threatening pulmonary embolisms when benefits surpass the risks of bleeding.

  • Embolectomy: Surgical removal of an embolus, noted for its risks and reserved for extreme scenarios.

Patient Education and Prevention Strategies

  • Risk Reduction Strategies: It includes smoking cessation, weight management for obese individuals, and encouraging regular movement during long travel.

  • Contraception Counseling: Suggestions for non-estrogen birth control options for patients at high risk.

  • Monitoring: Patients should be alert for signs and symptoms of DVT or recurrent pulmonary embolisms.