PE

Questions and Answers

Which of the following best describes the typical effects of smaller thrombi in the lung?

They cause pleuritic chest pain due to inflammation near the parietal pleura. (correct)

They primarily obstruct large pulmonary arteries.

They do not produce any significant symptoms.

They lead to systemic hypotension and cardiogenic shock.

Which factor is NOT part of Virchow's triad that contributes to thrombosis in deep veins?

Diabetes Mellitus (correct)

Hypercoagulability states

Stasis of blood flow

Vessel wall injury

What is the clinical presentation characteristic of acute massive pulmonary embolism?

Sudden localized pleuritic chest pain and hemoptysis.

High fever and pleural friction rub.

Progressive exertional dyspnea and cor pulmonale.

Severe dyspnea and hemodynamic compromise. (correct)

Which presentation is commonly associated with pulmonary infarction?

Localized pleuritic chest pain and fever. Signup and view all the answers

What is a potential outcome of chronic pulmonary embolism?

Chronic obstructive pulmonary hypertension due to recurrent emboli. Signup and view all the answers

Which statement about gas exchange in the lungs during pulmonary embolism is correct?

V/Q mismatches primarily contribute to hypoxemia. Signup and view all the answers

Which of the following is NOT a typical complication associated with pulmonary embolism?

Pneumonia Signup and view all the answers

Identify the condition that can lead to vessel wall injury, contributing to thrombosis.

Trauma Signup and view all the answers

What condition leads to areas of low ventilation to perfusion ratios in the lungs?

Atelectasis due to loss of surfactant Signup and view all the answers

How do elevated right atrial pressures influence shunting during an acute pulmonary embolism?

They can open a patent foramen ovale, causing right-to-left shunting. Signup and view all the answers

Which classification of pulmonary embolism indicates hemodynamic instability?

Massive PE Signup and view all the answers

What is the most likely outcome if a D-dimer test is negative in a patient with low pretest probability of VTE?

VTE is ruled out. Signup and view all the answers

Which imaging technique is considered the gold standard for diagnosing pulmonary embolism?

Pulmonary angiography Signup and view all the answers

What is a common finding on a chest X-ray for someone with pulmonary embolism?

Wedge-shaped area of pulmonary infarction Signup and view all the answers

What occurs to the left ventricular cardiac output due to right ventricular overload in pulmonary embolism?

It decreases. Signup and view all the answers

Which laboratory test is typically elevated in patients with acute thrombotic disorders?

D-dimer Signup and view all the answers

What is the primary cause of most pulmonary embolism cases?

Deep vein thrombosis originating from the lower extremity Signup and view all the answers

Which of the following is a source of emboli that is least commonly associated with pulmonary embolism?

Inhaled smoke from burning materials Signup and view all the answers

Which type of thrombus poses a minimal embolic risk?

Calf-limited thrombus Signup and view all the answers

Which of the following conditions is most likely to lead to an embolus from pelvic veins?

Childbirth Signup and view all the answers

What is the most common source of acute symptomatic pulmonary embolism?

Thrombi above the popliteal vein Signup and view all the answers

Which type of embolus can arise from the right side of the heart?

Mural thrombi from bacterial endocarditis Signup and view all the answers

What process describes the obstruction of the pulmonary artery due to a traveled substance?

Venous thromboembolism Signup and view all the answers

After lodging in the lung, what can large thrombi cause?

Hemodynamic compromise Signup and view all the answers

What is a primary limitation of using MRI for diagnosing pulmonary embolism (PE)?

Limited sensitivity for distal PE Signup and view all the answers

Which of the following is NOT an advantage of V/Q scans over CT scans?

More widely available than CT technology Signup and view all the answers

What does a V/Q scan primarily detect?

Blood flow obstruction in the lung Signup and view all the answers

Which of the following ECG findings is commonly associated with a large pulmonary embolism?

S1Q3T3 pattern Signup and view all the answers

When initiating warfarin therapy after heparin, what is the recommended starting dose?

10 mg/day Signup and view all the answers

What is the target INR range for anticoagulation in venous thromboembolism?

2.0-3.0 Signup and view all the answers

Which of the following statements regarding low molecular weight heparin (LMWH) is false?

LMWH requires laboratory monitoring of PTT Signup and view all the answers

Which blood gas change typically accompanies hyperventilation due to a pulmonary embolism?

Hypocapnia Signup and view all the answers

What is a major advantage of NOACs over VKAs?

Minor drug and food interactions Signup and view all the answers

In which situation is an inferior vena cava (IVC) filter indicated?

Patients with acute VTE contraindicated to anticoagulant therapy Signup and view all the answers

What is the primary purpose of thrombolytic therapy?

To induce enzymatic destruction of clots Signup and view all the answers

What defines chronic thromboembolic pulmonary hypertension (CTEPH)?

Recurrent venous thromboembolism despite anticoagulation Signup and view all the answers

What measurement indicates pulmonary arterial hypertension (PAH)?

Mean pulmonary artery pressure >20 mm Hg Signup and view all the answers

Which option describes the definition of cor pulmonale?

Right ventricular alteration due to respiratory disorders Signup and view all the answers

What is a characteristic of Group 2 pulmonary hypertension?

Caused by left heart disease Signup and view all the answers

Which of the following is NOT a reason to perform surgical embolectomy?

Stable patients after receiving thrombolysis Signup and view all the answers

Study Notes

Definition and Causes of Pulmonary Embolism

Pulmonary embolism (PE) is the obstruction of the pulmonary artery or its branches by an embolus, often originating from deep vein thrombosis (DVT).
Venous thromboembolism (VTE) leads to PE when a blood clot from limbs travels to the lungs.
Other embolic sources include:
- Fat: released from bone marrow due to fractures or burns.
- Tumor fragments: can break off from cancerous growths.
- Air bubbles: may enter the bloodstream during medical procedures or resuscitation efforts.
- Amniotic fluid: can enter the circulation during childbirth.
- Talc: associated with intravenous drug use.

Sources of Emboli and Risk Factors

80-95% of VTE cases stem from thrombi in the lower extremities, especially the calf veins.
Thrombi that extend above the popliteal vein have a higher risk of causing acute PE.
Other possible embolic sources include pelvic veins (affected by pregnancy or surgery), upper extremities (via central venous catheters), and the right heart (mural thrombi or vegetations).
Key risk factors for DVT and PE include:
- Stasis: due to immobility or age.
- Hypercoagulability: due to obesity, pregnancy, malignancy, and surgery.
- Vessel wall injury: caused by inflammation or trauma.

Clinical Presentation of PE

Acute Massive PE: sudden severe chest pain, dyspnea, cardiogenic shock symptoms like hypotension and tachycardia, potential for sudden death.
Pulmonary Infarction: localized pleuritic chest pain, hemoptysis, fever, possible pleural rub or effusion.
Small PE: may cause reflex hyperventilation without significant symptoms.
Chronic PE: recurrent emboli leading to pulmonary hypertension and cor pulmonale indicated by exertional dyspnea and RV dysfunction.

Physiology and Pathophysiology

PE disrupts gas exchange, leading to hypoxemia, predominantly caused by ventilation-perfusion mismatches.
Increased dead space in alveoli reduces effective gas exchange.
Hemodynamic impact: right ventricular overload diminishes left ventricular output, risking cardiac compromise.

Classification of PE Severity

Non-massive PE: normotensive patients with normal RV function.
Massive PE: hemodynamic instability from RV failure.
Sub-massive PE: normotensive with RV dysfunction evident on imaging.

Diagnosis of PE

Diagnosis integrates clinical findings with laboratory tests (e.g., D-dimer) and imaging like CT pulmonary angiography.
Wells scoring system helps assess PE probability; scores above 4 warrant further diagnostic imaging.

Investigations

D-Dimer: sensitive for acute thrombotic disorders, negative results can aid in ruling out VTE.
Imaging options include:
- Chest X-ray: can show indirect signs of PE.
- CT pulmonary angiography: first-line, visualizes thrombi directly.
- Ventilation/perfusion (V/Q) scan: evaluates mismatches due to obstruction; safer for certain patients compared to CT.
- Echocardiography: assess right heart size and function.

PE Prophylaxis and Treatment

Prophylaxis for moderate to high-risk patients includes low-dose heparin.
Anticoagulant therapy: unfractionated heparin or low molecular weight heparin initiates therapy, followed by warfarin for long-term management (target INR of 2-3).
Thrombolytic therapy: indicated in massive PE with hemodynamic instability.
Inferior vena cava (IVC) filters: employed for patients who cannot tolerate anticoagulation.
Surgical options include embolectomy and pulmonary thromboendarterectomy for chronic cases.

Pulmonary Hypertension & Cor Pulmonale

Defined as mean pulmonary artery pressure >20 mm Hg; classified into five main groups based on underlying causes.
Cor pulmonale arises from chronic respiratory disorders causing RV dysfunction.
Chronic respiratory diseases associated include COPD and pulmonary thromboembolic disease.

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Description

This quiz explores the definition and causes of pulmonary embolism (PE), detailing its link to venous thromboembolism (VTE). Participants will learn about various sources of emboli, such as fat, tumor fragments, and air bubbles, as well as crucial risk factors for developing PE. Test your knowledge on this critical topic in vascular health.

PE