Pulmonary

Pulmonary US Medical PG Question 1: A 71-year-old man is admitted to the ICU with a history of severe pancreatitis and new onset difficulty breathing. His vital signs are a blood pressure of 100/60 mm Hg, heart rate of 100/min, respirations of 27/min, temperature of 36.7°C (98.1°F), and oxygen saturation of 85% on room air. Physical examination shows a cachectic male in severe respiratory distress. Rales are heard at the base of each lung. The patient is intubated and a Swan-Ganz catheter is inserted. Pulmonary capillary wedge pressure is 8 mm Hg. An arterial blood gas study reveals a PaO2: FiO2 ratio of 180. The patient is diagnosed with acute respiratory distress syndrome. In which of the following segments of the respiratory tract are the cells responsible for the symptoms observed in this patient found?

• A. Alveolar sacs (Correct Answer)
• B. Terminal bronchioles
• C. Bronchi
• D. Respiratory bronchioles
• E. Bronchioles

Pulmonary Explanation: ***Alveolar sacs*** - **Acute respiratory distress syndrome (ARDS)** is characterized by widespread inflammatory injury to the **alveolar-capillary membrane**, leading to increased permeability and fluid accumulation in the alveolar sacs. - The symptoms, including **severe hypoxemia** (PaO2:FiO2 ratio < 300), **non-cardiogenic pulmonary edema** (PCWP ≤ 18 mmHg), and **bilateral lung infiltrates**, directly result from damage to the **Type I and Type II pneumocytes** and endothelial cells within the alveolar units. *Terminal bronchioles* - These are the last airways that **do not contain alveoli**, primarily involved in air conduction rather than gas exchange. - While inflammation can extend to these structures in severe lung injury, the primary site of impaired gas exchange and fluid accumulation in ARDS occurs distal to them, in the respiratory zone. *Bronchi* - The bronchi are primarily involved in **air conduction** and consist of cartilage, smooth muscle, and ciliated epithelium, but they do not participate in gas exchange. - Injury to the bronchi would manifest as airway obstruction or mucus hypersecretion rather than the diffuse alveolar damage seen in ARDS. *Respiratory bronchioles* - These are the first airways that contain a **small number of alveoli** and participate in gas exchange, but their primary role is still more conductive than the alveolar sacs. - Although they can be affected in ARDS, the most critical damage and symptoms arise from the more extensive gas exchange surface of the alveolar sacs. *Bronchioles* - Bronchioles are small airways lacking cartilage, primarily responsible for **airflow regulation** and conduction. - While they can be affected by inflammation, the extensive impairment of gas exchange and the characteristic pathology of ARDS specifically involves the **alveolar units**, not primarily the bronchioles.

Pulmonary US Medical PG Question 2: A 63-year-old man presents to the emergency department because of progressive difficulty with breathing. He has a history of diabetes, hypertension, and chronic bronchitis. He has been receiving medications to moderate his conditions and reports being compliant with his schedule. He reports a recent difficulty with tackling simple chores in the house. He has not been able to walk for more than 1 block over the past few days. His persistent cough has also been worsening with more formation of sputum. During his diagnosis of bronchitis, about a year ago, he had a 40-pack-year smoking history. The patient is in evident distress and uses his accessory muscles to breathe. The vital signs include: temperature 38.6°C (101.5°F), blood pressure 120/85 mm Hg, pulse 100/min, respiratory rate 26/min, and oxygen (O2) saturation 87%. A decrease in breathing sounds with expiratory wheezes is heard on auscultation of the lungs. The arterial blood gas (ABG) analysis shows: PCO2 60 mm Hg PO2 45 mm Hg pH 7.3 HCO3– 25 mEq/L Which of the following is the most appropriate next step in the treatment?

• A. O2 supplementation (Correct Answer)
• B. Aminophylline
• C. Methylprednisolone
• D. Albuterol
• E. Levofloxacin

Pulmonary Explanation: ***O2 supplementation*** - The patient presents with **severe hypoxemia** (SpO2 87%, PO2 45 mm Hg), which is a life-threatening condition requiring immediate intervention. **Oxygen supplementation** is critical to improve tissue oxygenation and prevent organ damage. - The patient's presentation is consistent with an acute exacerbation of COPD, likely triggered by infection, where *initial management focuses on correcting hypoxemia* and *relieving bronchospasm*. - In COPD patients, **controlled oxygen therapy** is essential (target SpO2 88-92%) to avoid worsening CO2 retention, but with SpO2 of 87% and severe hypoxemia, oxygen remains the immediate priority. *Aminophylline* - Aminophylline is a **methylxanthine** with bronchodilatory effects, but its **narrow therapeutic index** and significant side effect profile (e.g., arrhythmias, seizures) make it a less favored first-line treatment for acute exacerbations of COPD. - While it can be considered in severe cases unresponsive to other therapies, it is not the most appropriate immediate next step given the patient's critical hypoxemia, where oxygen is paramount. *Methylprednisolone* - **Corticosteroids** like methylprednisolone are important in reducing inflammation during COPD exacerbations and improving lung function. - However, their full therapeutic effect takes hours to develop, and they do not immediately address the acute, life-threatening hypoxemia present in this patient. *Albuterol* - Albuterol is a **short-acting beta-agonist (SABA)**, which is crucial for *bronchodilation* in COPD exacerbations. It should be administered promptly to relieve airway obstruction. - While essential in managing the exacerbation, addressing the *severe hypoxemia* with oxygen takes immediate precedence to prevent organ damage, as albuterol will not directly increase oxygen saturation to a safe level alone. *Levofloxacin* - **Antibiotics** like levofloxacin are indicated when there's evidence of a bacterial infection triggering the COPD exacerbation, as suggested by increased sputum purulence and fever. - While important for treating the underlying infection, administering antibiotics does not immediately address the *acute respiratory distress* and *severe hypoxemia*, which are the most urgent concerns.

Pulmonary US Medical PG Question 3: A 67-year-old man is brought to the emergency department because of increasing shortness of breath that began while playing outdoors with his grandson. He has a history of asthma but does not take any medications for it. On arrival, he is alert and oriented. He is out of breath and unable to finish his sentences. His pulse is 130/min, respirations are 23/min and labored, and blood pressure is 110/70 mm Hg. Physical examination shows nasal flaring and sternocleidomastoid muscle use. Pulmonary exam shows poor air movement bilaterally but no wheezing. Cardiac examination shows no abnormalities. Oxygen is administered via non-rebreather mask. He is given three albuterol nebulizer treatments, inhaled ipratropium, and intravenous methylprednisolone. The patient is confused and disoriented. Arterial blood gas analysis shows: pH 7.34 Pco2 44 mm Hg Po2 54 mm Hg O2 saturation 87% Which of the following is the most appropriate next step in management?

• A. Flexible bronchoscopy
• B. Intravenous magnesium sulfate therapy
• C. Endotracheal intubation (Correct Answer)
• D. Continuous albuterol nebulizer therapy
• E. Intravenous theophylline therapy

Pulmonary Explanation: ***Endotracheal intubation*** - The patient's **worsening mental status** (confused and disoriented after initial treatment) and persistent **hypoxemia** (PO2 54 mmHg, O2 sat 87%) despite aggressive therapy indicate impending **respiratory failure** and the need for immediate advanced airway management. - The **normal PCO2** (44 mmHg) in a patient with severe asthma exacerbation is concerning, as it suggests the patient is tiring and unable to maintain adequate ventilation, which can quickly lead to hypercapnia and respiratory arrest. *Flexible bronchoscopy* - This procedure is typically used for **diagnostic purposes** (e.g., investigating foreign body aspiration, airway obstruction, or pneumonia) and is not an immediate life-saving intervention for acute respiratory failure. - It would delay critical airway management and ventilation in a patient with rapidly deteriorating status. *Intravenous magnesium sulfate therapy* - **Magnesium sulfate** is a bronchodilator that can be used as an **adjunctive therapy** in severe asthma exacerbations, particularly in patients not responding to initial bronchodilator treatment. - However, it is not the primary intervention when a patient is showing signs of impending respiratory arrest and requires immediate airway protection and ventilatory support. *Continuous albuterol nebulizer therapy* - The patient has already received three albuterol nebulizer treatments, and while continuous albuterol can be beneficial in severe asthma, the patient's **deteriorating mental status** and **persistent hypoxemia** indicate he needs more aggressive respiratory support than just further bronchodilator therapy. - The immediate priority is to secure the airway and ensure adequate oxygenation and ventilation. *Intravenous theophylline therapy* - **Theophylline** is a bronchodilator with a narrow therapeutic window and significant potential for toxicity, making it a **third-line agent** for severe asthma that is refractory to standard treatments. - Its slow onset of action and potential side effects make it inappropriate as an initial or immediate intervention in a patient with acute respiratory failure.

Pulmonary US Medical PG Question 4: A previously healthy 64-year-old woman comes to the physician because of a dry cough and progressively worsening shortness of breath for the past 2 months. She has not had fever, chills, or night sweats. She has smoked one pack of cigarettes daily for the past 45 years. She appears thin. Examination of the lung shows a prolonged expiratory phase and end-expiratory wheezing. Spirometry shows decreased FEV1:FVC ratio (< 70% predicted), decreased FEV1, and a total lung capacity of 125% of predicted. The diffusion capacity of the lung (DLCO) is decreased. Which of the following is the most likely diagnosis?

• A. Bronchiectasis
• B. Interstitial lung disease
• C. Chronic obstructive pulmonary disease (Correct Answer)
• D. Hypersensitivity pneumonitis
• E. Bronchial asthma

Pulmonary Explanation: ***Chronic obstructive pulmonary disease*** - The patient's long history of **smoking (45 pack-years)**, **prolonged expiratory phase**, and **end-expiratory wheezing** are classic signs of airway obstruction. - Spirometry findings of a **decreased FEV1:FVC ratio** (< 70% predicted), **decreased FEV1**, **increased total lung capacity (TLC)**, and **decreased DLCO** are all highly indicative of **emphysema**, a subtype of COPD. *Bronchiectasis* - While it shares symptoms like cough and SOB, **bronchiectasis** is characterized by permanent **dilatation of bronchi** and profuse, chronic **sputum production**, which is not mentioned here. - Spirometry typically shows **obstructive patterns**, but the marked increase in TLC and decreased DLCO are more specific to emphysema. *Interstitial lung disease* - This condition primarily causes a **restrictive lung pattern**, meaning a decreased TLC and normal or increased FEV1:FVC ratio. - The patient's **increased TLC** and **obstructive spirometry** rule out a purely restrictive process. *Hypersensitivity pneumonitis* - This is an inflammatory response to inhaled antigens, often presenting with **recurrent episodes** of fever, chills, and cough, and can lead to restrictive physiology. - The patient lacks a history of specific **antigen exposure** and presents with an obstructive pattern and increased TLC. *Bronchial asthma* - While asthma shares obstructive features like wheezing and a decreased FEV1:FVC ratio, it is characterized by **reversibility** of airway obstruction and typically does not cause a significantly **elevated TLC** or **decreased DLCO** in uncomplicated cases. - The patient's long smoking history points away from asthma as the primary diagnosis.

Pulmonary US Medical PG Question 5: A 57-year-old man presents to the clinic for a chronic cough over the past 4 months. The patient reports a productive yellow/green cough that is worse at night. He denies any significant precipitating event prior to his symptoms. He denies fever, chest pain, palpitations, weight changes, or abdominal pain, but endorses some difficulty breathing that waxes and wanes. He denies alcohol usage but endorses a 35 pack-year smoking history. A physical examination demonstrates mild wheezes, bibasilar crackles, and mild clubbing of his fingertips. A pulmonary function test is subsequently ordered, and partial results are shown below: Tidal volume: 500 mL Residual volume: 1700 mL Expiratory reserve volume: 1500 mL Inspiratory reserve volume: 3000 mL What is the functional residual capacity of this patient?

• A. 4500 mL
• B. 2000 mL
• C. 2200 mL
• D. 3200 mL (Correct Answer)
• E. 3500 mL

Pulmonary Explanation: ***3200 mL*** - The **functional residual capacity (FRC)** is the volume of air remaining in the lungs after a normal expiration. - It is calculated as the sum of the **expiratory reserve volume (ERV)** and the **residual volume (RV)**. In this case, 1500 mL (ERV) + 1700 mL (RV) = 3200 mL. *4500 mL* - This value represents the sum of the **inspiratory reserve volume (3000 mL)** and the **residual volume (1700 mL)**, which does not correspond to a standard lung volume or capacity. - It does not logically relate to the definition of functional residual capacity. *2000 mL* - This value represents the sum of the **tidal volume (500 mL)** and the **expiratory reserve volume (1500 mL)**, which is incorrect for FRC. - This would represent the inspiratory capacity minus the inspiratory reserve volume, which is not a standard measurement used in pulmonary function testing. *2200 mL* - This value could be obtained by incorrectly adding the **tidal volume (500 mL)** and the **residual volume (1700 mL)**, which is not the correct formula for FRC. - This calculation represents a miscombination of lung volumes that does not correspond to any standard pulmonary capacity measurement. *3500 mL* - This value is the sum of the **tidal volume (500 mL)**, the **expiratory reserve volume (1500 mL)**, and the **residual volume (1700 mL)**. - This would represent the FRC plus the tidal volume, which is not a standard measurement and does not represent the functional residual capacity.

Pulmonary US Medical PG Question 6: A 65-year-old man presents to the emergency department with shortness of breath. He was at home cleaning his yard when his symptoms began. The patient is a farmer and does not have regular medical care. He has smoked two packs of cigarettes every day for the past 40 years. The patient lives alone and admits to feeling lonely at times. His temperature is 99.5°F (37.5°C), blood pressure is 159/95 mmHg, pulse is 90/min, respirations are 19/min, and oxygen saturation is 86% on room air. On physical exam, you note a man in distress. Pulmonary exam reveals poor air movement, wheezing, and bibasilar crackles. Cardiac exam is notable for an S4 heart sound. The patient is started on appropriate therapy and his symptoms improve. Prior to discharge he is no longer distressed when breathing and his oxygen saturation is 90% on room air. Which of the following interventions could improve mortality the most in this patient?

• A. Varenicline (Correct Answer)
• B. Albuterol
• C. Ipratropium
• D. Home oxygen
• E. Magnesium

Pulmonary Explanation: ***Varenicline*** - This patient presents with symptoms highly suggestive of an **acute exacerbation of COPD** (shortness of breath, poor air movement, wheezing, significant smoking history). **Smoking cessation** is the single most effective intervention to improve mortality in patients with COPD, and varenicline is a highly effective medication for this purpose. - While other interventions manage acute symptoms, quitting smoking addresses the underlying progressive lung damage and **reduces the risk of future exacerbations and overall mortality**. *Albuterol* - **Albuterol** is a **short-acting beta-agonist (SABA)** used as a rescue inhaler to provide rapid bronchodilation during an acute exacerbation of COPD. - While essential for **symptomatic relief** and managing acute episodes, it does not impact the long-term progression of COPD or overall mortality. *Ipratropium* - **Ipratropium** is a **short-acting muscarinic antagonist (SAMA)** that also causes bronchodilation and is used in the acute management of COPD exacerbations, often in combination with SABAs. - Like albuterol, it provides **symptomatic relief** but does not alter the disease course or improve long-term mortality. *Home oxygen* - **Home oxygen therapy** is indicated for patients with severe, chronic hypoxemia (PaO2 < 55 mmHg or SaO2 < 88%) on room air to improve quality of life and decrease mortality. - While beneficial for select patients with **chronic hypoxemia**, it is not a primary intervention for acute exacerbations or a more impactful mortality-reducing strategy than smoking cessation for a patient who continues to smoke. *Magnesium* - **Intravenous magnesium sulfate** can be considered in severe, life-threatening asthma exacerbations or acute COPD exacerbations that are unresponsive to standard bronchodilator therapy. - It works by inducing **bronchial smooth muscle relaxation** but is a therapy for acute rather than chronic management or mortality improvement.

Pulmonary US Medical PG Question 7: A 72-year-old man being treated for benign prostatic hyperplasia (BPH) is admitted to the emergency department for 1 week of dysuria, nocturia, urge incontinence, and difficulty initiating micturition. His medical history is relevant for hypertension, active tobacco use, chronic obstructive pulmonary disease, and BPH with multiple urinary tract infections. Upon admission, he is found with a heart rate of 130/min, respiratory rate of 19/min, body temperature of 39.0°C (102.2°F), and blood pressure of 80/50 mm Hg. Additional findings during the physical examination include decreased breath sounds, wheezes, crackles at the lung bases, and intense right flank pain. A complete blood count shows leukocytosis and neutrophilia with a left shift. A sample for arterial blood gas analysis (ABG) was taken, which is shown below. Laboratory test Serum Na+ 140 mEq/L Serum Cl- 102 mEq/L Serum K+ 4.8 mEq/L Serum creatinine (SCr) 2.3 mg/dL Arterial blood gas pH 7.12 Po2 82 mm Hg Pco2 60 mm Hg SO2% 92% HCO3- 12.0 mEq/L Which of the following best explains the patient’s condition?

• A. Metabolic acidosis complicated by respiratory alkalosis
• B. Non-anion gap metabolic acidosis
• C. Respiratory alkalosis complicated by metabolic acidosis
• D. Respiratory acidosis complicated by metabolic alkalosis
• E. Metabolic acidosis complicated by respiratory acidosis (Correct Answer)

Pulmonary Explanation: ***Metabolic acidosis complicated by respiratory acidosis*** - The patient's pH is significantly low (7.12), indicating **acidemia**. The **HCO3- is markedly low (12 mEq/L)**, and PCO2 is elevated (60 mm Hg), suggesting both a metabolic and a respiratory component to the acidosis. - The severe infection (fever, elevated heart rate, hypotension, flank pain, leukocytosis, elevated creatinine) and the signs of hypoperfusion contribute to **lactic acidosis (metabolic acidosis)**, while his history of COPD and lung findings (decreased breath sounds, wheezes, crackles) explain the impaired ventilation leading to **respiratory acidosis**. *Metabolic acidosis complicated by respiratory alkalosis* - While a **metabolic acidosis** is clearly present due to the low pH and HCO3-, the PCO2 is elevated, indicating **respiratory acidosis**, not alkalosis. - Respiratory alkalosis would be characterized by a **low PCO2** due to hyperventilation. *Non-anion gap metabolic acidosis* - To determine the anion gap, we use the formula: **Na+ - (Cl- + HCO3-)**. In this case, 140 - (102 + 12) = 140 - 114 = **26 mEq/L**. - An anion gap of 26 mEq/L, which is significantly elevated (normal range is typically 8-12 mEq/L), indicates an **anion gap metabolic acidosis**, not a non-anion gap one. *Respiratory alkalosis complicated by metabolic acidosis* - The low pH and HCO3- confirm **metabolic acidosis**, but the elevated PCO2 (60 mm Hg) indicates **respiratory acidosis**, not alkalosis, as the respiratory component is also acidotic. - Respiratory alkalosis would result from **hyperventilation and a low PCO2**. *Respiratory acidosis complicated by metabolic alkalosis* - While the elevated PCO2 indicates **respiratory acidosis**, the HCO3- is significantly low (12 mEq/L), which points to a **metabolic acidosis**, not metabolic alkalosis. - **Metabolic alkalosis** would be characterized by an **elevated HCO3-**.

Pulmonary US Medical PG Question 8: A 72-year-old obese man presents as a new patient to his primary care physician because he has been feeling tired and short of breath after recently moving to Denver. He is a former 50 pack-year smoker and has previously had deep venous thrombosis. Furthermore, he previously had a lobe of the lung removed due to lung cancer. Finally, he has a family history of a progressive restrictive lung disease. Laboratory values are obtained as follows: Oxygen tension in inspired air = 130 mmHg Alveolar carbon dioxide tension = 48 mmHg Arterial oxygen tension = 58 mmHg Respiratory exchange ratio = 0.80 Respiratory rate = 20/min Tidal volume = 500 mL Which of the following mechanisms is consistent with these values?

• A. Shunt physiology
• B. High altitude
• C. V/Q mismatch
• D. Pulmonary fibrosis
• E. Hypoventilation (Correct Answer)

Pulmonary Explanation: ***Hypoventilation*** - The arterial oxygen tension (PaO2) of 58 mmHg is consistent with hypoxemia, and the alveolar carbon dioxide tension (PACO2) of 48 mmHg (normal 35-45 mmHg) indicates **hypercapnia**, a hallmark of hypoventilation. - The **alveolar-arterial (A-a) gradient** can be calculated using the alveolar gas equation: PAO2 = PiO2 - PACO2/R. Here, PAO2 = 130 mmHg - 48 mmHg/0.8 = 130 - 60 = 70 mmHg. The A-a gradient is PAO2 - PaO2 = 70 - 58 = 12 mmHg, which is within the normal range (5-15 mmHg), indicating that the hypoxemia is primarily due to **decreased alveolar ventilation**. *Shunt physiology* - A shunt would cause a significant reduction in PaO2 and a **widened A-a gradient** (typically >15 mmHg) due to deoxygenated blood bypassing ventilated areas. - While shunts do not typically cause hypercapnia unless very severe, the normal A-a gradient here rules out a significant shunt as the primary mechanism for hypoxemia. *High altitude* - Moving to a high altitude (like Denver) causes a decrease in **inspired oxygen tension (PiO2)**, leading to hypoxemia. - However, the provided inspired oxygen tension (130 mmHg) is above what would be expected for significant high-altitude hypoxemia at sea level equivalent, and the hypoxemia here is associated with hypercapnia, which is not a direct result of high altitude itself. *V/Q mismatch* - A V/Q mismatch leads to hypoxemia and a **widened A-a gradient**, as some areas of the lung are either underventilated or underperfused. - While it can cause hypoxemia, a V/Q mismatch is typically associated with **normal or low PaCO2** due to compensatory hyperventilation, not hypercapnia, and the A-a gradient would be elevated. *Pulmonary fibrosis* - Pulmonary fibrosis is a restrictive lung disease that leads to impaired gas exchange, causing hypoxemia primarily due to **V/Q mismatch** and **diffusion limitation**. - This would result in a **widened A-a gradient** and often a **low PaCO2** due to compensatory hyperventilation, rather than the elevated PaCO2 observed in this patient.

Pulmonary US Medical PG Question 9: A 72-year-old man is brought to the emergency department after an episode of hemoptysis. He has a chronic cough that is productive of copious sputum. Six years ago, he had a stroke that left him with difficulty swallowing. He smoked one pack of cigarettes daily for 40 years, but quit 2 years ago. His respirations are 25/min and labored. Physical examination shows digital clubbing. An x-ray of the chest shows tram track opacities in the lower lung fields. Which of the following is the most likely diagnosis?

• A. Aspiration pneumonia
• B. Bronchiectasis (Correct Answer)
• C. Emphysema
• D. Lung cancer
• E. Chronic bronchitis

Pulmonary Explanation: ***Bronchiectasis*** - The combination of **chronic cough with copious sputum**, **hemoptysis**, **digital clubbing**, and **tram track opacities** on chest x-ray is highly characteristic of bronchiectasis. - The patient's history of difficulty swallowing following a stroke suggests a risk factor for recurrent aspirations leading to chronic infection and airway damage characteristic of bronchiectasis. *Aspiration pneumonia* - While the patient has a risk factor for aspiration due to difficulty swallowing, aspiration pneumonia typically presents as an acute infection with fever and infiltrates, rather than chronic symptoms and specific radiographic findings like **tram track opacities** and **digital clubbing**. - Aspiration pneumonia may lead to bronchiectasis if chronic, but it is not the most definitive diagnosis given the full constellation of findings described. *Emphysema* - Emphysema is a form of COPD characterized by destruction of alveolar walls and presents with **dyspnea**, **barrel chest**, and often a history of smoking, but does not typically cause **hemoptysis** or **tram track opacities**. - Chest x-rays in emphysema usually show **hyperinflation** and **flattened diaphragms**, not specific airway dilation. *Lung cancer* - While **hemoptysis** and **chronic cough** can be symptoms of lung cancer, and the patient has a significant smoking history, lung cancer does not typically cause **copious sputum** or **tram track opacities**. - Although digital clubbing can occur with lung cancer as a paraneoplastic syndrome, the presence of **tram track opacities** is pathognomonic for bronchiectasis and points strongly to this diagnosis. *Chronic bronchitis* - Chronic bronchitis is defined by a **chronic productive cough** for at least three months in two consecutive years and is associated with smoking. - However, it does not typically cause **hemoptysis**, **digital clubbing**, or the specific **tram track opacities** seen on x-ray, which indicate bronchial wall thickening and dilation.

Pulmonary US Medical PG Question 10: A 22-year-old woman presents to the emergency department with a chief concern of shortness of breath. She was hiking when she suddenly felt unable to breathe and had to take slow deep breaths to improve her symptoms. The patient is a Swedish foreign exchange student and does not speak any English. Her past medical history and current medications are unknown. Her temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 120/min, respirations are 22/min, and oxygen saturation is 90% on room air. Physical exam is notable for poor air movement bilaterally and tachycardia. The patient is started on treatment. Which of the following best describes this patient's underlying pathology? FEV1 = Forced expiratory volume in 1 second FVC = Forced vital capacity DLCO = Diffusing capacity of carbon monoxide

• A. Increased FVC
• B. Increased FEV1
• C. Increased FEV1/FVC
• D. Decreased airway tone
• E. Normal DLCO (Correct Answer)

Pulmonary Explanation: ***Normal DLCO*** - This patient presents with an acute exacerbation of what is likely **asthma**, showing symptoms of **shortness of breath**, **tachycardia**, poor air movement bilaterally, and improvement with slow deep breaths. **Asthma** characteristically affects the airways and not the alveoli, thus the **diffusing capacity of carbon monoxide (DLCO)**, which measures gas exchange across the alveolar-capillary membrane, would be expected to be normal. - In asthma, the primary problem is **bronchoconstriction** and **airway inflammation**, which restricts airflow but does not typically impair the diffusion of gases like carbon monoxide across the alveolar-capillary membrane. *Increased FVC* - **Forced vital capacity (FVC)** is often normal or even slightly reduced in asthma due to **air trapping** and early airway closure, not increased. - An increased FVC is usually not associated with obstructive lung diseases like asthma but could potentially be seen in conditions where lung volumes are pathologically large, which is not the case here. *Increased FEV1* - **Forced expiratory volume in 1 second (FEV1)** is typically **decreased** in obstructive lung diseases like asthma due to **airflow limitation**. - An increased FEV1 would indicate better-than-average expiratory flow, which contradicts the symptoms of shortness of breath and poor air movement in this patient. *Increased FEV1/FVC* - The **FEV1/FVC ratio** is characteristically **decreased** in obstructive lung diseases like asthma, indicating that a disproportionately smaller amount of air can be exhaled in the first second relative to the total forced vital capacity. - An increased FEV1/FVC ratio would be a sign of a restrictive lung disease or normal lung function, not an exacerbation of an obstructive process. *Decreased airway tone* - The underlying pathology in asthma is typically **bronchoconstriction**, which means an **increased airway tone** and narrowing of the airways, rather than decreased. - Decreased airway tone would imply bronchodilation, which would alleviate, not cause, the patient's symptoms of shortness of breath and poor air movement.

Pulmonary Flashcard 1 of 10

Question: Gross examination of pulmonary infarction due to PE reveals a hemorrhagic, _____-shaped infarct

Answer: wedge

Pulmonary Flashcard 2 of 10

Question: _____ pneumonia is characterized by diffuse interstitial infiltrates

Answer: Interstitial (atypical)

Pulmonary Flashcard 3 of 10

Question: Recovery of ARDS may be complicated by _____ due to loss of type II pneumocytes

Answer: interstitial fibrosis/scarring

Pulmonary Flashcard 4 of 10

Question: Hypersensitivity pneumonitis can lead to interstitial fibrosis and _____ lung disease with chronic exposure to the inhaled antigen

Answer: restrictive

Pulmonary Flashcard 5 of 10

Question: A Ghon complex is composed of a _____ and _____.

Answer: Ghon focus

Pulmonary Flashcard 6 of 10

Question: _____ is characterized by macrophages laden with carbon, causing inflammation and fibrosis

Answer: Coal workers' pneumoconiosis

Extra Information:   Watch Pneumoconioses [https://dashboard.sketchy.com/study/medical/courses/medical-pathophysiology/units/medical-pathophysiology-pulmonary/videos/medical-pathophysiology-pulmonary-restrictive-lung-disease-pneumoconioses?utm_source=anki&utm_medium=partnership&utm_campaign=february_update&utm_content=medical]Watch associated Bootcamp video [https://app.bootcamp.com/med-school/pulmonology/videos/restrictive-lung-disease?index=6] https://onlinemeded.org/spa/pulmonary/restrictive-lung-disease/acquire?ref=anki 

Pulmonary Flashcard 7 of 10

Question: One complication associated with lung cancer is _____ due to compression of the recurrent laryngeal nerve

Answer: hoarseness

Extra Information:   Watch Lung Carcinoma [https://dashboard.sketchy.com/study/medical/courses/medical-pathophysiology/units/medical-pathophysiology-pulmonary/videos/medical-pathophysiology-pulmonary-lung-cancer-lung-carcinoma?utm_source=anki&utm_medium=partnership&utm_campaign=february_update&utm_content=medical]Watch associated Bootcamp video [https://app.bootcamp.com/med-school/pulmonology/videos/lung-cancer?index=2] https://onlinemeded.org/spa/pulmonology/lung-cancer/acquire?ref=anki 

Pulmonary Flashcard 8 of 10

Question: In conditions that cause destruction of the _____, hemosiderin laden macrophages may be seen in the alveoli

Answer: pulmonary vasculature

Extra Information:  https://onlinemeded.org/spa/pulmonology?ref=anki 

Pulmonary Flashcard 9 of 10

Question: Which two pneumoconioses increase the risk for cor pulmonale? _____

Answer: Berylliosis and Silicosis

Extra Information:  Watch Pneumoconioses [https://dashboard.sketchy.com/study/medical/courses/medical-pathophysiology/units/medical-pathophysiology-pulmonary/videos/medical-pathophysiology-pulmonary-restrictive-lung-disease-pneumoconioses?utm_source=anki&utm_medium=partnership&utm_campaign=february_update&utm_content=medical] https://onlinemeded.org/spa/pulmonary/restrictive-lung-disease/acquire?ref=anki 

Pulmonary Flashcard 10 of 10

Question: Which pneomoconioses may produce centriacinar emphysema predominently in the upper lobes of the lung? _____

Answer: Simple coal worker's pneumoconiosis

Extra Information:  Watch Pneumoconioses [https://dashboard.sketchy.com/study/medical/courses/medical-pathophysiology/units/medical-pathophysiology-pulmonary/videos/medical-pathophysiology-pulmonary-restrictive-lung-disease-pneumoconioses?utm_source=anki&utm_medium=partnership&utm_campaign=february_update&utm_content=medical] https://onlinemeded.org/spa/pulmonary/restrictive-lung-disease/acquire?ref=anki