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Which of the following is a major symptom of pulmonary thromboembolism (PTE)?
RV hypocontractile free wall with hypercontractile apex can be seen in the assessment of venous thromboembolism.
True
What is the primary imaging method used to visualize clot in the pulmonary artery?
CT Pulmonary angiography (CTPA)
In submassive VTE, RV ischemia is indicated by elevated levels of _____ and _____.
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Match the following clinical symptoms with their corresponding descriptions:
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Which of the following conditions is associated with variable extrathoracic upper airway obstruction?
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Chronic Obstructive Pulmonary Disease (COPD) is staged based on pre-bronchodilator FEV1 measurements.
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What is the forced expiratory volume in 1 second (FEV1) level that indicates Stage III COPD?
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A condition that causes ___________ airway obstruction is tracheal stenosis.
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Match the following respiratory conditions with their classifications:
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What does DLCO measure?
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A normal DLCO value ranges between 10-20 mL per minute/mmHg.
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What is the normal physiology percentage range for DLCO values?
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The normal DLCO values are between _____ mL per minute/mmHg.
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Match the following DLCO-related terms with their descriptions:
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What does the maximal mid expiratory flow rate (MMEFR) indicate in small airway disease?
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A normal FEV1/FVC ratio can be diagnosed using a spirometer.
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What is the normal percentage for closing volume when measured in relation to vital capacity (VC)?
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In the flow-volume curve, a ______ curve is characterized by a pronounced coving in the expiratory phase.
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Match the following flow-volume curve situations with their corresponding descriptors:
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What does a decreased FVC typically indicate?
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An increased DLCO is always indicative of intraparenchymal lung disease.
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What is the coefficient of diffusion denoted as in pulmonary function tests?
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In the evaluation of lung diseases, a reduced ___ may indicate vascular lung disease.
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Match the following spirometry values with the appropriate lung condition:
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What is the V/P ratio in normal ventilation?
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Dyspnea and pleuritic chest pain occur before cough and hemoptysis in pulmonary embolism.
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What is a common sign associated with hypoxia in pulmonary embolism?
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In shunt physiology, the V/P ratio is equal to _____
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Match the following clinical symptoms with their features:
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What does Westermark's sign indicate?
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Atypical patterns are the most common findings in an ECG of a patient with suspected pulmonary issues.
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What is the most common cause of acute cor pulmonale?
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Massive VTE is defined as pulmonary embolism with hypotension.
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What does an enlarged central pulmonary artery, also known as Fleischner sign, suggest?
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The ECG finding known as _____ indicates right ventricular strain or hypertrophy.
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Name one high-risk site for thrombi during pregnancy.
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The mortality rate for massive pulmonary thromboembolism (PTE) can be as high as _____ in severe cases.
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Match the following ECG findings with their descriptions:
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Match the following VTE characteristics with their descriptions:
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Which condition is associated with increased DLCO?
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Exercise can lead to an increase in DLCO.
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What condition is characterized by thickened respiratory membranes, resulting in decreased DLCO?
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_________ is a condition that can cause a decreased DLCO due to vascular changes in the lungs.
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Match the following respiratory disorders with their associated DLCO changes:
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Which of the following factors can cause a false low DLCO reading?
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Polycythemia is associated with a decreased DLCO.
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Name one factor that can cause a decrease in DLCO.
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Which of the following is the most common genetic risk factor for pulmonary complications?
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COPD is a major acquired risk factor for pulmonary infarction.
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What complication can arise from pulmonary embolism?
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The ________ ratio is maximum at the apex of the lungs.
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Match the following acquired risk factors with their descriptions:
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Study Notes
Venous Thromboembolism (VTE)
- VTE is a serious condition that occurs when blood clots form in veins and travel to the lungs, causing pulmonary thromboembolism (PTE).
- The most common symptom of VTE is unexplained dyspnea (difficulty breathing) with clear lung fields, followed by sudden cardiac death and syncope (fainting).
VTE Assessment
- The "Golden 4" is a crucial assessment tool for VTE diagnosis.
- Clinical: A critical component involves observing for hypotension (low blood pressure).
- ECHO (Echocardiogram): Provides visual information about the heart and specifically looks for signs of McConnell's sign, septal push, a weakened left ventricular contraction, and potential hypercontractility at the apex of the right ventricle. It also aims to rule out pericardial tamponade.
- Biomarkers: NT pro BNP is a biomarker associated with right ventricular dilation while troponin I can indicate right ventricular ischemia.
- Imaging Evidence: CT pulmonary angiography (CTPA) is considered the gold standard for VTE diagnosis. It visualizes clots in the pulmonary arteries and often reveals signs like a dilated pulmonary artery, a large right ventricle, and potential left ventricular outflow tract obstruction.
Submassive VTE
- This classification of VTE is characterized by the absence of hypotension.
- Right ventricular dilation and ischemia are present, but these can be low-risk or high-risk based on biomarker analysis, specifically elevated NT pro BNP and troponin I.
Non-massive VTE
- Non-massive VTE represents a significant portion of VTE cases, accounting for 10-20% of all cases.
- It is characterized by the peripheral lodging of emboli (blood clots).
Clinical Features
- Recurring episodes of pneumonia or non-resolving pneumonia
- Cough
- Pleuritic chest pain
- Hemoptysis (coughing up blood)
Pulmonary Function Tests
- The flow-volume curve in respiratory function tests is a crucial tool that helps visualize the flow of air (L/sec) versus lung volume (L) both during inspiration and expiration.
- This allows professionals to assess the efficiency and health of the lungs, particularly the airway passages.
- Patterns in the curve can indicate obstructive and restrictive lung diseases.
Respiratory Conditions
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Variable extrathoracic UAO: This refers to a variable upper airway obstruction occurring outside the chest cavity and may involve conditions like vocal cord palsy, laryngeal tumors, goiter, and obstructive sleep apnea syndrome.
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Variable intrathoracic UAO: This refers to a variable upper airway obstruction occurring within the chest cavity and may involve conditions like foreign body obstruction or tracheomalacia.
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Fixed upper airway obstruction (UAO): This describes a fixed type of obstruction occurring in the upper airway and might be caused by tracheal stenosis.
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Neuromuscular Weakness: This may also contribute to respiratory issues.
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Restrictive parenchymal lung disease: This represents another potential respiratory condition affecting the lung tissue.
COPD Staging
- Chronic Obstructive Pulmonary Disease (COPD) is staged based on the patient's forced expiratory volume in one second (FEV1) after bronchodilator administration.
- Stage I: FEV1 ≥ 80%
- Stage II: FEV1 < 80% to 50%
- Stage III: FEV1 < 50% to 30%
- Stage IV: FEV1 < 30%
DLCO/Transfer Factor
- DLCO (Diffusing Capacity of the Lungs for Carbon Monoxide) tests the ability of the lungs to transfer gases across the respiratory membrane.
- A normal DLCO value ranges from 20-30 mL per minute/mmHg, which translates to 70-140% of the predicted value.
Coefficient of Diffusion (Kco)
- Kco is essentially the same as DLCO.
- It considers the lung's volume and is used to further evaluate the diffusion capabilities of the lungs, especially in restrictive lung diseases.
Approach to Evaluation of Lung Diseases
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Sprometry: This involves several key measurements:
- FEV1: This represents the forced expiratory volume in the first second. A FEV1 score of 0.7 indicates normal lung function.
- FVC: This represents the forced vital capacity, the total volume of air that can be exhaled. A reduced FVC typically signifies an obstructive lung disease.
- Post-bronchodilator FEV1: This measures the FEV1 after the administration of bronchodilators, and an increase in the FEV1 score is seen in conditions like asthma and COPD.
- DLCO : This is a measure of how easily gases can diffuse across the respiratory membrane. A reduced DLCO may indicate vascular lung disease, early interstitial lung disease, or other issues affecting the effectiveness of gas exchange.
Small Airway Disease
- Normal FEV1/FVC ratios do not allow for a direct diagnosis of the small airway disease using spirometry.
- Small airway disease typically has a normal FVC.
- Additionally, a small airway disease can often be diagnosed using the following criteria:
- A reduced maximal mid-expiratory flow rate (MMEFR)
- An increased closing volume.
FLOW-VOLUME CURVE
- This graphic representation of expiratory flow against lung volume is a valuable tool for visualizing the efficiency of airflow in the lungs.
- It helps identify patterns associated with lung obstruction (like a "dog-tail" appearance) and restriction (like a flattened curve), in both the expiratory and inspiratory phases.
Venous Thromboembolism (VTE)
- Pulmonary thromboembolism (PTE) is another name for VTE.
- The mortality rate for massive VTE can be extremely high, reaching 60-80%.
VTE Pathogenesis
- Thrombi (blood clots) and microthrombi migrate from systemic circulation to the pulmonary vasculature.
- The most common source of these thrombi is the deep veins in the lower limbs.
- Individuals with thrombi in the supra-popliteal veins, femoral veins, or pelvic veins are at a higher risk for VTE.
- Acute cor pulmonale develops as a consequence of VTE where dilation and hypertrophy of the right ventricle occur, potentially leading to heart failure.
Types of VTE
- Massive VTE: This severe type is characterized by pulmonary embolism causing hypotension.
- The pathogenesis of massive VTE involves significant obstruction in the pulmonary circulation, leading to hypoxemia, dilation of the right ventricle and right atrium, and a decline in cardiac output.
Investigations
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CXR (Chest X-ray): CXR findings suggestive of VTE include:
- Long linear bands of atelectasis, which are thin bands of collapsed lung tissue.
- Pleural-based wedge-shaped opacities known as Hampton's hump.
- Oligemia (reduced blood flow) of the right upper lung, also known as Westermark's sign.
- Enlarged central pulmonary artery, referred to as Fleischner's sign.
- An enlarged right descending artery, also known as Pallas sign.
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ECG (Electrocardiogram):
- T-wave inversion is often seen in these cases.
- Late transition is another possible ECG pattern.
- The ECG helps identify any potential strain or hypertrophy in the right ventricle.
Dead Space Ventilation
- This occurs when air enters the alveoli, but there is no blood flow to those alveoli.
- This type of ventilation is seen in pulmonary emboli.
Shunt Physiology
- This occurs when blood passes through the pulmonary vessels without experiencing oxygenation, essentially bypassing the gas exchange process.
Clinical Features of VTE
- The symptoms of VTE depend on the size and location of the emboli.
- Common symptoms include:
- Dyspnea
- Pleuritic chest pain
- Cough
- Hemoptysis.
- The signs of VTE can include:
- Tachypnea
- Tachycardia
- Rales
- Decreased breath sounds.
- Complications of VTE can include:
- Shock
- S3 heart sound
- Hypotension
- Elevated jugular venous pressure.
- Type I respiratory failure with hypoxia due to ventilation-perfusion mismatch but a normal partial pressure of carbon dioxide in arterial blood ( PaCO2 ), and a widened alveolar-arterial oxygen gradient.
- Type II respiratory failure with hypoxia and hypercarbia due to parenchymal involvement.
DLCO in Respiratory Disorders
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Conditions with increased DLCO:
- Diffuse alveolar hemorrhage
- Polycythemia
- Supine (increased venous return)
- Exercise
- Left-to-right shunting
- Obesity
- Pregnancy
- Mild congestive heart failure (HF)
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Conditions with decreased DLCO:
- Anemia
- Pulmonary edema
- False low DLCO can occur due to high-flow oxygen or smoking.
DLCO and Respiratory Disorders
- Asthma: ↑ DLCO.
- Emphysema: Normal DLCO.
- Chronic bronchitis: ↓ DLCO.
- Intraparenchymal restrictive lung disease (ILD): ↓ DLCO.
- Extraparenchymal restrictive lung disease: ↓ DLCO.
- Vascular lung disease: ↓ DLCO.
- Pulmonary hypertension: ↓ DLCO.
- Chronic thromboembolic pulmonary vascular disorders: ↓ DLCO.
Active Space
- The text refers to a specific area or situation referred to as "Active Space" but does not elaborate on what this means.
Investigations in Active Space
- ECHO: Normal
- BP: Normal
- Biomarkers: Normal
Complications in Active Space
- Pulmonary infarction: This refers to the death of lung tissue due to lack of blood supply.
Risk Factors for Pulmonary Embolism
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Genetics:
- Factor-V Leiden mutation: This is the most common genetic risk factor for PE.
- Antithrombin III deficiency
- Protein C deficiency
- Protein S deficiency.
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Acquired Risk Factors:
- Antiphospholipid antibody syndrome
- Polycythemia vera
- Primary myelofibrosis
- Heparin-induced thrombocytopenia
- Paroxysmal nocturnal hemoglobinuria
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Malignancy:
- Adenocarcinoma (a type of cancer) is a risk factor for PE.
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Other:
- COPD
- Congestive cardiac failure
- Nephrotic syndrome, specifically membranous nephropathy, due to the loss of antithrombin III in urine.
- Oral contraceptive pills
- Hormone replacement therapy
- Pregnancy and post-partum period
- Surgeries requiring immobilization for greater than 4 days
- Orthopedic surgeries.
Physiology
- Ventilation (V): This is the rate at which air is moved into and out of the lungs and is highest at the base of the lungs.
- Perfusion (P): The amount of blood flow through the lungs is also highest at the base of the lungs.
- Ventilation-Perfusion ratio (V/P): This ratio is highest at the apex of the lungs, as the decrease in perfusion is greater than the decrease in ventilation.
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Description
Test your knowledge on the diagnosis and management of Venous Thromboembolism (VTE). This quiz covers symptoms, the 'Golden 4' assessment components, and relevant imaging and biomarker findings. Prepare to explore the critical aspects of VTE and its implications for patient care.
