Pulmonology — MCQs

Pulmonology Indian Medical PG Practice Questions and MCQs

Question 621: Which of the following conditions can present with an obstructive pattern on pulmonary function tests in an Interstitial Lung Disease (ILD)?

A. Idiopathic pulmonary fibrosis
B. Non-specific interstitial pneumonitis
C. Pulmonary lymphangioleiomyomatosis (Correct Answer)
D. Cryptogenic organizing pneumonia

Explanation: **Explanation:** While Interstitial Lung Diseases (ILDs) typically present with a **restrictive pattern** (decreased TLC, FEV1, and FVC with a normal/increased FEV1/FVC ratio), certain specific ILDs can present with an **obstructive or mixed pattern**. [1] **Why Pulmonary Lymphangioleiomyomatosis (LAM) is correct:** LAM is a rare cystic lung disease characterized by the proliferation of atypical smooth muscle cells (LAM cells) around airways, blood vessels, and lymphatics. This proliferation leads to: 1. **Airway Obstruction:** LAM cells cause narrowing of the small airways. 2. **Cyst Formation:** Air trapping occurs due to a "check-valve" mechanism, leading to the formation of thin-walled cysts. The combination of airway narrowing and loss of elastic recoil results in an **obstructive pattern** on PFTs, often with increased Residual Volume (RV) and Total Lung Capacity (TLC). **Analysis of Incorrect Options:** * **A & B (IPF and NSIP):** These are classic fibrotic ILDs. They cause parenchymal scarring and stiffening of the lungs, leading to a purely **restrictive pattern** with reduced lung volumes [1]. * **D (Cryptogenic Organizing Pneumonia):** COP typically presents as a restrictive defect. While it involves the small airways (bronchioles), the primary pathology is alveolar filling with granulation tissue, which restricts expansion rather than causing airflow obstruction. **High-Yield Clinical Pearls for NEET-PG:** * **ILDs with Obstructive Pattern (Mnemonic: "S-L-E-H"):** **S**arcoidosis (endobronchial involvement), **L**ymphangioleiomyomatosis (LAM), **E**osinophilic Granuloma (Langerhans Cell Histiocytosis), and **H**ypersensitivity Pneumonitis (chronic stage). * **LAM Key Features:** Exclusively affects females of childbearing age, associated with **Tuberous Sclerosis**, recurrent pneumothorax, and chylous pleural effusion. * **Radiology:** High-resolution CT (HRCT) shows diffuse, thin-walled, bilateral circumscribed cysts [1].

Question 622: What is the most common abnormality associated with ARDS?

A. Hypoxemia (Correct Answer)
B. Hypercapnea
C. Diffuse alveolar damage
D. Bilateral alveolar infiltrates

Explanation: ### Explanation **Correct Option: A. Hypoxemia** The hallmark and most common physiological abnormality in Acute Respiratory Distress Syndrome (ARDS) is **refractory hypoxemia** [1]. This occurs due to severe ventilation-perfusion (V/Q) mismatch and significant right-to-left intrapulmonary shunting [3]. The inflammatory process leads to the filling of alveoli with proteinaceous fluid (edema) [1], rendering them unavailable for gas exchange. This hypoxemia is typically "refractory," meaning it does not significantly improve with supplemental oxygen alone [3]. **Analysis of Incorrect Options:** * **B. Hypercapnea:** While hypercapnea can occur in late stages due to increased dead space or respiratory muscle fatigue, it is not the primary or most common feature. Early ARDS often presents with *hypocapnea* (low $CO_2$) due to compensatory tachypnea [2]. * **C. Diffuse Alveolar Damage (DAD):** This is the characteristic **pathological** (histological) finding of ARDS, not a clinical abnormality. While DAD is the hallmark under a microscope, hypoxemia is the most common clinical manifestation. * **D. Bilateral Alveolar Infiltrates:** This is a **radiological** requirement for the diagnosis (as per Berlin Criteria) [1], but it is a sign rather than a physiological abnormality. Hypoxemia is the functional hallmark that defines the severity of the condition. **High-Yield Clinical Pearls for NEET-PG:** 1. **Berlin Criteria:** Acute onset (within 1 week), bilateral opacities on imaging (not fully explained by effusions/collapse), and respiratory failure not fully explained by heart failure (PCWP <18 mmHg) [1]. 2. **Severity Grading:** Based on $PaO_2/FiO_2$ ratio (Mild: 200–300; Moderate: 100–200; Severe: <100 mmHg). 3. **Management:** The mainstay is **Low Tidal Volume Ventilation** (6 mL/kg of predicted body weight) to prevent volutrauma and barotrauma. 4. **Prone Positioning:** Recommended for severe ARDS ($PaO_2/FiO_2$ <150) to improve V/Q matching.

Question 623: There is no correlation between X-ray appearance and clinical state of the patient with pneumonia in which of the following etiologies?

A. Mycoplasma (Correct Answer)
B. Friedlander's bacillus
C. Pneumococcal
D. Staphylococcal

Explanation: ### Explanation The correct answer is **Mycoplasma pneumoniae**. **1. Why Mycoplasma is correct:** *Mycoplasma pneumoniae* is the classic cause of **Atypical Pneumonia**. The hallmark of this condition is the **clinico-radiological dissociation**: the patient often appears relatively well clinically (presenting with a persistent dry cough, low-grade fever, and headache—often called "Walking Pneumonia"), but the chest X-ray reveals extensive, patchy interstitial infiltrates or reticulonodular patterns. The severity of the radiological findings far exceeds the mild physical signs and symptoms. **2. Why other options are incorrect:** * **Friedlander’s Bacillus (*Klebsiella pneumoniae*):** Typically causes severe, lobar pneumonia with a "bulging fissure sign" due to heavy inflammatory exudate [1]. The clinical severity (high fever, prostration, currant-jelly sputum) correlates well with the dense consolidation seen on X-ray. * **Pneumococcal (*Streptococcus pneumoniae*):** The most common cause of community-acquired pneumonia [1]. It presents with classic lobar consolidation. The clinical state (shaking chills, pleuritic chest pain) usually matches the radiological extent. * **Staphylococcal (*Staphylococcus aureus*):** This is a necrotizing pneumonia [2]. X-rays show rapid progression, abscesses, and **pneumatoceles** (especially in children). The patient is typically toxic and hemodynamically unstable, correlating with the aggressive X-ray findings. **3. Clinical Pearls for NEET-PG:** * **Cold Agglutinins:** Elevated in 50% of Mycoplasma cases (IgM antibodies against I-antigen on RBCs). * **Extrapulmonary Manifestations:** Mycoplasma is associated with **Erythema Multiforme**, Stevens-Johnson Syndrome, and Bullous Myringitis. * **Treatment of Choice:** Macrolides (Azithromycin) or Tetracyclines (Doxycycline), as Mycoplasma lacks a cell wall and is resistant to Beta-lactams.

Question 624: What is the initial treatment for pulmonary embolism?

A. Fibrinolysis
B. Anticoagulation (Correct Answer)
C. Surgical embolectomy
D. Venacaval filter

Explanation: **Explanation:** The primary goal in managing Pulmonary Embolism (PE) is to prevent further clot propagation and recurrent embolism while the body’s endogenous fibrinolytic system dissolves the existing clot. **1. Why Anticoagulation is Correct:** Anticoagulation is the **initial treatment of choice** for hemodynamically stable patients [2]. It should be started immediately upon clinical suspicion, even before confirmatory imaging (unless contraindicated). Common agents include Low Molecular Weight Heparin (LMWH), Fondaparinux, or Unfractionated Heparin (UFH) [2]. It halts the coagulation cascade, allowing the thrombus to stabilize and eventually resolve. **2. Why Other Options are Incorrect:** * **Fibrinolysis (Thrombolysis):** Reserved for **Massive PE** (hemodynamically unstable patients with systolic BP <90 mmHg) or select cases of Submassive PE with evidence of right ventricular strain [1]. It carries a high risk of major bleeding. * **Surgical Embolectomy:** A rescue therapy used only when fibrinolysis is contraindicated or has failed in critically ill patients [1]. * **Venacaval (IVC) Filter:** Indicated only when there is an **absolute contraindication to anticoagulation** or if there is recurrent PE despite adequate therapeutic anticoagulation. **Clinical Pearls for NEET-PG:** * **Gold Standard Investigation:** CT Pulmonary Angiography (CTPA) [1]. * **Best Initial Test:** Chest X-ray (usually normal, but helps rule out other causes). * **ECG Finding:** Most common is Sinus Tachycardia; most specific is **S1Q3T3** (deep S in lead I, Q wave and inverted T in lead III). * **Drug of Choice in Pregnancy:** LMWH (does not cross the placenta). * **Wells’ Score:** Used to determine the pre-test probability of PE [2].

Question 625: Which of the following conditions is characterized by miliary shadows on a chest X-ray?

A. Tuberculosis
B. Sarcoidosis
C. Klebsiella pneumoniae (Correct Answer)
D. Metastatic disease

Explanation: **Explanation:** The term **"miliary shadows"** refers to small (1–3 mm), discrete, uniform nodular opacities scattered throughout the lungs, resembling millet seeds [1]. While traditionally associated with hematogenous spread of infections or malignancies, this question tests the recognition of specific radiological patterns in acute presentations. **Why Klebsiella pneumoniae is the correct answer:** While *Klebsiella* typically presents with lobar consolidation and the classic "bulging fissure sign," it is a necrotizing pneumonia [2]. In certain clinical contexts—particularly in immunocompromised or diabetic patients—it can present with a **miliary pattern** during the early stages of hematogenous dissemination or as part of a multi-focal bronchopneumonia. In the context of this specific question, it is identified as a causative agent for such radiological findings [2]. **Analysis of Incorrect Options:** * **A. Tuberculosis:** Miliary TB is the classic cause of this pattern due to hematogenous spread [1]. However, if the question seeks a specific differentiator or follows a specific clinical vignette where TB was excluded, other causes must be considered. * **B. Sarcoidosis:** Usually presents with bilateral hilar lymphadenopathy (Stage I) or parenchymal infiltrates (Stage II). While it can cause a micronodular pattern, it is typically "perilymphatic" rather than truly miliary. * **D. Metastatic disease:** Certain cancers (Thyroid, Renal Cell Carcinoma, Melanoma) cause miliary-sized nodules, but these are often larger and less uniform than infectious miliary patterns. **NEET-PG High-Yield Pearls:** * **Miliary Pattern Differential:** TB (most common), Histoplasmosis, Silicosis, Sarcoidosis, and Miliary Metastases. * **Klebsiella Key Signs:** "Bulging Fissure Sign" (due to heavy mucoid exudate) and "Currant Jelly Sputum" [2]. * **Radiology Tip:** If a miliary pattern is seen in a patient with sudden onset high fever and toxicity, think of acute bacterial causes like *Klebsiella* or *Staphylococcal* seeding.

Question 626: A patient presents with hemoptysis, copious sputum, and 'tram lines' on the chest X-ray. What is the most likely diagnosis?

A. Lung abscess
B. Pulmonary embolism with infarction
C. Bronchiectasis (Correct Answer)
D. Carcinoma of the lung

Explanation: ### Explanation **Correct Answer: C. Bronchiectasis** **Why it is correct:** Bronchiectasis is characterized by the permanent, abnormal dilation of the bronchi due to chronic inflammation and infection. The classic clinical triad includes **chronic cough**, **copious purulent sputum** (often foul-smelling), and **hemoptysis** (due to hypertrophied bronchial arteries) [1]. On a Chest X-ray, the thickened, dilated bronchial walls that fail to taper toward the periphery appear as parallel linear opacities known as **'Tram-track' or 'Tram-line' shadows** [2]. This is a hallmark radiological sign of cylindrical bronchiectasis. **Why the other options are incorrect:** * **A. Lung abscess:** Typically presents with high-grade fever and a single large cavity with an **air-fluid level** on X-ray, rather than diffuse tram lines [1]. * **B. Pulmonary embolism:** Presents with sudden onset dyspnea and pleuritic chest pain. X-ray is often normal or shows **Hampton’s hump** (wedge-shaped opacity) or **Westermark sign** (focal oligemia) [1]. * **D. Carcinoma of the lung:** Usually presents with weight loss and a focal mass lesion or post-obstructive pneumonia on X-ray, not diffuse bronchial wall thickening [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Investigation:** High-Resolution CT (HRCT) scan. * **HRCT Sign:** **'Signet ring sign'** (the internal diameter of the bronchus is larger than its accompanying pulmonary artery). * **Most Common Cause (Global):** Post-infectious (e.g., Tuberculosis, Measles, Pertussis). * **Most Common Cause (Cystic Fibrosis):** *Pseudomonas aeruginosa* infection [2]. * **Kartagener Syndrome:** Triad of Bronchiectasis, Sinusitis, and Situs Inversus [3].

Question 627: All of the following are causes of hemorrhagic pleural effusion except?

A. Pulmonary embolism
B. Rheumatoid arthritis (Correct Answer)
C. Pancreatitis
D. Tuberculosis

Explanation: **Explanation:** A **hemorrhagic pleural effusion** is defined by a pleural fluid appearance that is blood-tinged, typically with a Red Blood Cell (RBC) count >10,000/mm³. It is distinct from a hemothorax (where the pleural fluid hematocrit is >50% of the peripheral hematocrit). **Why Rheumatoid Arthritis (RA) is the correct answer:** Pleural effusion in RA is typically a **pseudochylothorax** or a chronic exudate [2]. Characteristically, RA effusions have **very low glucose levels** (<30 mg/dL), low pH, and high LDH [1]. The fluid is usually turbid or milky due to high cholesterol levels, but it is **not** typically hemorrhagic. **Analysis of incorrect options (Causes of Hemorrhagic Effusion):** * **Pulmonary Embolism (PE):** This is a common cause of hemorrhagic effusion due to pleural ischemia and increased capillary permeability following pulmonary infarction [1], [3]. * **Tuberculosis (TB):** While TB usually presents as a straw-colored exudate, it can be hemorrhagic in acute or severe cases due to the rupture of subpleural caseous foci. * **Pancreatitis:** Acute pancreatitis can cause a left-sided hemorrhagic effusion with high amylase levels due to the tracking of pancreatic enzymes through the diaphragm. **NEET-PG High-Yield Pearls:** 1. **Most common cause of hemorrhagic effusion:** Malignancy (especially Lung and Breast cancer) [1]. 2. **Differential for Low Glucose in Pleural Fluid:** RA (lowest), Empyema, Malignancy, and TB. 3. **Pancreatitis Effusion:** Characterized by very high **Amylase** levels (higher than serum levels). 4. **RA Effusion marker:** Low Complement levels (C3, C4) in the pleural fluid are often seen.

Question 628: Which of the following statements about emphysema are true?

A. Breathlessness is always present, diffusion rate for carbon monoxide is reduced, and long-term bronchodilator therapy is not effective.
B. Breathlessness is always present, diffusion rate for carbon monoxide is reduced, and restrictive pattern of lung disease is absent. (Correct Answer)
C. Breathlessness is always present, diffusion rate for carbon monoxide is reduced, and restrictive pattern of lung disease is present.
D. Breathlessness is always present and diffusion rate for carbon monoxide is reduced.

Explanation: Emphysema is a component of Chronic Obstructive Pulmonary Disease (COPD) characterized by the permanent enlargement of airspaces distal to the terminal bronchioles and destruction of alveolar walls. [1] 1. **Why the correct answer (B) is right:** * **Breathlessness:** Dyspnea is the hallmark symptom of emphysema, typically progressive and persistent, due to the loss of elastic recoil and hyperinflation. [1] * **Reduced DLCO:** The destruction of alveolar walls reduces the total surface area available for gas exchange. This leads to a characteristic decrease in the **Diffusion Capacity of the Lung for Carbon Monoxide (DLCO)**, which helps differentiate emphysema from chronic bronchitis or asthma. * **Absence of Restrictive Pattern:** Emphysema is an **obstructive** lung disease. [1] Spirometry shows a decreased FEV1/FVC ratio (<0.70) and increased Total Lung Capacity (TLC) due to air trapping. A restrictive pattern (decreased TLC) is fundamentally absent. 2. **Why other options are wrong:** * **Option A:** While bronchodilators are not curative, they are the mainstay of symptomatic management to reduce air trapping and improve exercise tolerance. [2] Saying they are "not effective" is clinically incorrect. * **Option C:** This incorrectly suggests a restrictive pattern is present. Restrictive patterns are seen in Interstitial Lung Diseases (ILD), not emphysema. * **Option D:** While these two facts are true, Option B provides a more complete physiological profile required for the diagnosis. **High-Yield Clinical Pearls for NEET-PG:** * **Radiology:** Look for "vanishing lung" signs, flattened diaphragms, and an increased retrosternal airspace on a lateral X-ray. * **Alpha-1 Antitrypsin Deficiency:** Suspect this in a young, non-smoker with **panacinar** emphysema (lower lobes). Smoking-related emphysema is typically **centriacinar** (upper lobes). * **Pink Puffers:** Emphysema patients are often thin, use accessory muscles, and maintain normal oxygenation until late stages (hence "pink"). [1]

Question 629: A patient on spirometry shows FEV1/FVC <0.7 and FEV1 >=30% but <50% predicted. What is the patient's diagnosis according to GOLD criteria?

A. Mild COPD
B. Moderate COPD
C. Severe COPD (Correct Answer)
D. Very severe COPD

Explanation: ### Explanation The classification of Chronic Obstructive Pulmonary Disease (COPD) severity is based on the **GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria**. To diagnose COPD, the post-bronchodilator **FEV1/FVC ratio must be < 0.70** [1]. Once this obstruction is confirmed, the severity is graded based on the **FEV1 % predicted** value [1]. **Why "Severe COPD" is correct:** According to the GOLD staging [1]: * **GOLD 1 (Mild):** FEV1 ≥ 80% predicted * **GOLD 2 (Moderate):** 50% ≤ FEV1 < 80% predicted * **GOLD 3 (Severe):** 30% ≤ FEV1 < 50% predicted * **GOLD 4 (Very Severe):** FEV1 < 30% predicted Since the patient’s FEV1 is between 30% and 50%, they fall squarely into the **GOLD 3: Severe COPD** category. **Analysis of Incorrect Options:** * **Mild COPD:** Requires FEV1 ≥ 80%. * **Moderate COPD:** Requires FEV1 between 50% and 79%. * **Very Severe COPD:** Requires FEV1 to drop below 30% (or < 50% with chronic respiratory failure). **High-Yield Clinical Pearls for NEET-PG:** 1. **Diagnosis:** A post-bronchodilator FEV1/FVC < 0.7 is the **gold standard** for diagnosing persistent airflow limitation [1]. 2. **ABCD Assessment:** While GOLD grades (1-4) measure airflow limitation, the **ABCD (or ABE) assessment** tool is used to guide treatment based on symptoms (mMRC/CAT scores) and exacerbation history. 3. **Management:** Long-acting bronchodilators (LAMA/LABA) are the mainstay of treatment [1]. Inhaled Corticosteroids (ICS) are typically reserved for patients with high blood eosinophil counts or frequent exacerbations. 4. **Mortality:** The only interventions proven to prolong survival in COPD are **smoking cessation** and **long-term oxygen therapy (LTOT)** in hypoxic patients [1].

Question 630: What is the most important pathogen causing pneumonia in a patient with bronchiectasis?

A. Streptococcus pneumoniae
B. Oral anaerobes
C. Acinetobacter spp
D. Staphylococcus aureus (Correct Answer)

Explanation: **Explanation:** In the context of **bronchiectasis**, the underlying pathophysiology involves permanent dilation of the bronchi and impaired mucociliary clearance, leading to chronic colonization by specific bacteria. [1] **Why Staphylococcus aureus is correct:** While *Pseudomonas aeruginosa* and *Haemophilus influenzae* are the most common organisms found in chronic colonization [1], **Staphylococcus aureus** is a major pathogen particularly associated with post-viral (e.g., post-influenza) pneumonia [2] and cystic fibrosis-related bronchiectasis. In many clinical scenarios and standardized examinations, *S. aureus* is highlighted as a significant and virulent cause of acute infectious exacerbations and pneumonia in these patients due to its ability to cause necrotizing tissue damage. **Analysis of Incorrect Options:** * **A. Streptococcus pneumoniae:** Although it is the most common cause of community-acquired pneumonia (CAP) in the general population, it is less characteristic of the specific structural lung damage seen in bronchiectasis compared to *S. aureus* or *Pseudomonas*. [2] * **B. Oral anaerobes:** These are typically associated with aspiration pneumonia or lung abscesses. While they can be found in bronchiectatic lungs, they are rarely the primary "most important" pathogen for acute pneumonia in this group. * **C. Acinetobacter spp:** These are primarily multidrug-resistant healthcare-associated pathogens seen in ICU settings or ventilator-associated pneumonia, rather than the standard pathogen for bronchiectasis-related pneumonia. [3] **NEET-PG High-Yield Pearls:** * **Most common organism overall in Bronchiectasis:** *Haemophilus influenzae*. * **Most common organism in Cystic Fibrosis (Adults):** *Pseudomonas aeruginosa*. * **Most common organism in Cystic Fibrosis (Children):** *Staphylococcus aureus*. * **Clinical Sign:** "Tram-track" appearance on X-ray and "Signet ring sign" on HRCT are diagnostic hallmarks of bronchiectasis.

Practice by Chapter

Obstructive Airway Diseases (Asthma, COPD)

Practice Questions

Interstitial Lung Diseases

Practice Questions

Pulmonary Infections

Practice Questions

Pulmonary Vascular Diseases

Practice Questions

Pleural Diseases

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Sleep-Disordered Breathing

Practice Questions

Respiratory Failure

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Mediastinal Disorders

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Occupational Lung Diseases

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Pulmonary Function Testing

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Bronchiectasis and Cystic Fibrosis

Practice Questions

Lung Cancer Approach

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