Pulmonology — MCQs

Pulmonology Indian Medical PG Practice Questions and MCQs

Question 601: Type I respiratory failure best relates to which of the following?

A. Alveolar hypoventilation
B. Alveolar flooding (Correct Answer)
C. Hypoperfusion of respiratory muscles
D. Lung atelectasis

Explanation: ### Explanation **Type I Respiratory Failure (Hypoxemic)** is defined by a partial pressure of arterial oxygen ($PaO_2$) < 60 mmHg with a normal or low $PaCO_2$ [1]. The primary underlying mechanism is **Ventilation-Perfusion (V/Q) mismatch** or **Shunting** [2]. **Why "Alveolar Flooding" is correct:** Alveolar flooding (seen in conditions like Pulmonary Edema, Pneumonia, or ARDS) fills the alveoli with fluid, pus, or blood [3]. This prevents air from reaching the gas-exchange surface while blood flow (perfusion) continues. This creates a **right-to-left shunt**, where deoxygenated blood bypasses ventilated alveoli, leading to profound hypoxemia (Type I failure) [4]. **Analysis of Incorrect Options:** * **A. Alveolar hypoventilation:** This is the hallmark of **Type II Respiratory Failure** (Hypercapnic) [1]. It results in the retention of $CO_2$ ($PaCO_2$ > 45 mmHg) due to reduced minute ventilation [2]. * **C. Hypoperfusion of respiratory muscles:** This leads to **Type IV Respiratory Failure**, typically seen in cardiogenic, hypovolemic, or septic shock. Here, the primary issue is inadequate oxygen delivery to the muscles of respiration, leading to fatigue. * **D. Lung atelectasis:** While atelectasis can cause V/Q mismatch, "Alveolar flooding" is a more classic and comprehensive representation of the acute parenchymal lung diseases that define Type I failure in clinical exams. --- ### High-Yield Clinical Pearls for NEET-PG: * **Type I (Hypoxemic):** $PaO_2$ ↓, $PaCO_2$ Normal/↓. Mechanism: V/Q mismatch, Shunt, Diffusion defect [2]. * **Type II (Hypercapnic):** $PaO_2$ ↓, $PaCO_2$ ↑. Mechanism: Pump failure (CNS, nerves, muscles, chest wall) [1]. * **Type III (Peri-operative):** Result of atelectasis in the postoperative period. * **Type IV (Shock):** Respiratory failure due to decreased perfusion of respiratory muscles. * **A-a Gradient:** Increased in Type I failure; Normal in Type II failure (if the lungs themselves are healthy).

Question 602: A woman presents with a 6-week history of low-grade fever. A chest radiograph shows bihilar adenopathy with clear lung fields. Which of the following investigations would NOT be useful in the differential diagnosis?

A. CD4/CD8 counts in the blood (Correct Answer)
B. Serum ACE levels
C. Contrast-enhanced computed tomography (CECT) of the chest
D. Gallium scan

Explanation: The clinical presentation of **bihilar lymphadenopathy** with a low-grade fever in a patient with clear lung fields is a classic "textbook" description of **Stage I Sarcoidosis** [1]. The goal of investigations is to confirm the diagnosis and rule out differentials like tuberculosis or lymphoma. **Why Option A is the correct answer:** While the **CD4/CD8 ratio in Bronchoalveolar Lavage (BAL) fluid** is a highly useful diagnostic marker for sarcoidosis (typically showing a ratio >3.5:1), the **CD4/CD8 ratio in peripheral blood** is non-specific and does not reflect the localized pulmonary inflammatory process. Therefore, blood counts do not aid in the differential diagnosis of hilar adenopathy. **Analysis of other options:** * **Serum ACE levels (B):** Elevated in about 60-80% of patients with active sarcoidosis. While not specific, it helps support the diagnosis and monitor disease activity. * **CECT Chest (C):** This is the gold standard for evaluating mediastinal and hilar lymphadenopathy [2]. It helps differentiate sarcoidosis (typically symmetrical) from malignancy or TB (often asymmetrical or necrotic) and detects subtle parenchymal involvement. * **Gallium-67 Scan (D):** Though less commonly used now, it shows characteristic uptake patterns like the **"Panda sign"** (lacrimal/parotid glands) and **"Lambda sign"** (bihilar/paratracheal nodes) in sarcoidosis. **NEET-PG High-Yield Pearls:** * **Lofgren’s Syndrome:** A specific acute presentation of sarcoidosis consisting of the triad: Erythema nodosum, Bilateral hilar lymphadenopathy, and Polyarthritis/Arthralgia [1]. * **Kveim Test:** An older skin test for sarcoidosis (now largely obsolete). * **Biopsy:** The definitive diagnosis of sarcoidosis requires the demonstration of **non-caseating granulomas** on histopathology.

Question 603: A 25-year-old man presents with infertility, a lifelong history of productive cough, recurrent pulmonary infections, chronic abdominal pain, diarrhea, difficulty gaining weight, and diabetes mellitus. His chest x-ray suggests bronchiectasis. What is the most likely diagnosis?

A. Immunoglobulin deficiency
B. Cystic fibrosis (Correct Answer)
C. Whipple disease
D. Chronic obstructive pulmonary disease (COPD)

Explanation: ### Explanation **Correct Option: B. Cystic Fibrosis (CF)** The clinical presentation is a classic "textbook" description of Cystic Fibrosis. CF is an autosomal recessive disorder caused by mutations in the **CFTR gene**, leading to defective chloride transport and thick, viscous secretions [1]. * **Respiratory:** Thick mucus leads to impaired mucociliary clearance, recurrent infections, and permanent airway dilation (**Bronchiectasis**) [1]. * **Gastrointestinal:** Pancreatic insufficiency causes malabsorption (diarrhea/steatorrhea and difficulty gaining weight). Chronic pancreatitis eventually leads to **Cystic Fibrosis-Related Diabetes (CFRD)**. * **Reproductive:** Infertility in males is seen in >95% of cases, typically due to **Congenital Bilateral Absence of the Vas Deferens (CBAVD)** [1]. **Why Incorrect Options are Wrong:** * **A. Immunoglobulin Deficiency:** While it causes recurrent infections and bronchiectasis, it does not typically cause pancreatic insufficiency, diabetes, or CBAVD. * **C. Whipple Disease:** Caused by *Tropheryma whipplei*, it presents with diarrhea, weight loss, and arthralgia, but not chronic bronchiectasis or neonatal-onset respiratory issues. * **D. COPD:** Usually occurs in older patients with a smoking history. It does not explain multisystem involvement like infertility or pancreatic malabsorption in a 25-year-old. --- ### NEET-PG High-Yield Pearls * **Gold Standard Diagnosis:** Sweat Chloride Test (Value **>60 mmol/L** on two occasions). * **Most Common Mutation:** **ΔF508** (Class II mutation – protein misfolding). * **Microbiology:** *Staphylococcus aureus* is the most common pathogen in early childhood; ***Pseudomonas aeruginosa*** becomes dominant in adults. * **Radiology:** Bronchiectasis in CF typically involves the **upper lobes** (unlike Kartagener syndrome, which often involves the lower lobes). * **Newer Treatments:** CFTR modulators (e.g., Ivacaftor, Lumacaftor) target specific genetic defects.

Question 604: Which of the following is NOT a feature of adult respiratory distress syndrome?

A. Hypoxia
B. Hypocapnia
C. Low protein pulmonary edema (Correct Answer)
D. Stiff lungs

Explanation: ### Explanation **Adult Respiratory Distress Syndrome (ARDS)** is characterized by **non-cardiogenic pulmonary edema** resulting from increased alveolar-capillary permeability [1]. **1. Why "Low protein pulmonary edema" is the correct answer:** In ARDS, the primary pathology is diffuse alveolar damage (DAD). Inflammatory mediators cause significant damage to the capillary endothelium and alveolar epithelium. This leads to the leakage of **protein-rich fluid** (exudate) into the alveolar space. In contrast, "low protein" or transudative edema is a hallmark of cardiogenic pulmonary edema (congestive heart failure), where hydrostatic pressure pushes fluid out while keeping proteins within the vessels. **2. Analysis of Incorrect Options:** * **Hypoxia (Option A):** This is a cardinal feature. It occurs due to right-to-left shunting and V/Q mismatch as alveoli fill with fluid and collapse [1]. It is typically refractory to supplemental oxygen [2]. * **Hypocapnia (Option B):** In the early stages of ARDS, patients develop tachypnea and hyperventilation due to hypoxia and stimulation of J-receptors. This leads to increased CO2 washout, resulting in respiratory alkalosis and hypocapnia. (Hypercapnia only occurs in late-stage respiratory failure) [2]. * **Stiff Lungs (Option D):** The accumulation of fluid and the loss of surfactant lead to a marked decrease in **lung compliance** [1]. This makes the lungs "stiff" and difficult to ventilate, requiring higher pressures. **3. NEET-PG High-Yield Pearls:** * **Berlin Definition Criteria:** Acute onset (within 1 week), bilateral opacities on imaging, PaO2/FiO2 ratio < 300 mmHg, and edema not fully explained by heart failure [1]. * **PCWP:** In ARDS, the Pulmonary Capillary Wedge Pressure is typically **< 18 mmHg** (ruling out a cardiac cause). * **Pathological hallmark:** Hyaline membrane formation. * **Ventilatory Strategy:** Low tidal volume (6 mL/kg) ventilation is the gold standard to prevent volutrauma.

Question 605: Bronchial asthma can be diagnosed by which of the following findings?

A. Wheeze (Correct Answer)
B. Dyspnea
C. Normal FEV1
D. Cough

Explanation: **Explanation:** Bronchial asthma is a chronic inflammatory airway disease characterized by **reversible airway obstruction**, bronchial hyperresponsiveness, and inflammation. **Why Wheeze is the Correct Answer:** While asthma presents with a classic triad of symptoms (cough, dyspnea, and wheeze), **wheeze** is the most characteristic physical finding. It is a high-pitched, whistling sound produced by turbulent airflow through narrowed intrathoracic airways. In the context of a clinical diagnosis, the presence of a polyphonic, expiratory wheeze is highly suggestive of asthma, especially when it is episodic and triggered by specific allergens or exercise. **Analysis of Incorrect Options:** * **B. Dyspnea:** This is a common symptom of asthma but is highly non-specific. It occurs in numerous cardiac (e.g., heart failure) and pulmonary (e.g., COPD, pneumonia) conditions. * **C. Normal FEV1:** A normal FEV1 does not diagnose asthma. While patients may have normal lung function between attacks, the hallmark of asthma is a **reduced FEV1/FVC ratio** during an episode, which shows **reversibility** (increase in FEV1 >12% and >200ml) after bronchodilator inhalation. * **D. Cough:** Although "Cough Variant Asthma" exists, cough alone is the most common presenting symptom for a vast array of respiratory illnesses (from the common cold to lung cancer) and lacks the diagnostic specificity of a wheeze. **NEET-PG High-Yield Pearls:** * **Gold Standard for Diagnosis:** Spirometry demonstrating reversible airflow obstruction. * **Diurnal Variation:** Peak Expiratory Flow Rate (PEFR) variability >10% is diagnostic. * **FeNO:** Fraction of exhaled Nitric Oxide is a marker of eosinophilic airway inflammation. * **Drug of Choice (Acute):** SABA (Salbutamol); **Maintenance:** ICS-Formoterol (as per GINA guidelines).

Question 606: Alpha-1 antitrypsin deficiency presents as which of the following conditions?

A. Emphysema (Correct Answer)
B. Bronchiectasis
C. Empyema
D. Bronchogenic carcinoma

Explanation: ### Explanation **Correct Answer: A. Emphysema** **Pathophysiology:** Alpha-1 Antitrypsin (AAT) is a protease inhibitor synthesized in the liver [1]. Its primary role is to inhibit **Neutrophil Elastase**, an enzyme that breaks down elastin in the alveolar walls [1]. In AAT deficiency, the lack of this protective "anti-elastase" leads to unchecked destruction of the lung parenchyma, resulting in **Panacinar (Panlobular) Emphysema** [1]. Unlike smoking-related emphysema (which is typically centriacinar and affects the upper lobes), AAT deficiency characteristically involves the **lower lobes**. **Analysis of Incorrect Options:** * **B. Bronchiectasis:** While chronic lung destruction in AAT deficiency can occasionally lead to secondary bronchiectasis, it is not the primary or classic presentation. Bronchiectasis is more typically associated with Cystic Fibrosis or Kartagener syndrome. * **C. Empyema:** This refers to pus in the pleural space, usually secondary to bacterial pneumonia or thoracic surgery. It is an infectious process, not a genetic protease-antiprotease imbalance. * **D. Bronchogenic carcinoma:** While chronic lung inflammation is a risk factor for malignancy, AAT deficiency is specifically linked to emphysema and liver cirrhosis, not primarily as a cause of lung cancer. **Clinical Pearls for NEET-PG:** 1. **Genetics:** Autosomal codominant inheritance; the **PiZZ** genotype is associated with the most severe clinical disease [1]. 2. **Liver Involvement:** Misfolded AAT proteins accumulate in the endoplasmic reticulum of hepatocytes, leading to **Liver Cirrhosis**. Histology shows **PAS-positive, diastase-resistant globules**. 3. **Diagnosis:** Suspect in a young, non-smoker (age <45) presenting with lower-lobe emphysema. 4. **Radiology:** Chest X-ray shows hyperinflation and flattening of the diaphragm, predominantly at the bases.

Question 607: Reactivation of pulmonary tuberculosis always occurs at which location?

A. Lower part of the upper lobe
B. Upper part of the lower lobe
C. Lower part of the lower lobe
D. Apex of the upper lobe (Correct Answer)

Explanation: ### Explanation **1. Why the Apex of the Upper Lobe is Correct:** Reactivation (Secondary) Tuberculosis typically occurs in the **apical and posterior segments of the upper lobes**. The primary physiological reason is the **high oxygen tension ($PO_2$)** found in the lung apices [2]. *Mycobacterium tuberculosis* is an obligate aerobe that thrives in oxygen-rich environments. In a standing individual, the ventilation-perfusion ($V/Q$) ratio is highest at the apex because gravity reduces blood flow more significantly than ventilation. This creates an environment with high alveolar oxygen concentration and relatively poor lymphatic drainage, allowing the dormant bacilli (from a previous primary infection) to proliferate. **2. Why the Other Options are Incorrect:** * **Lower part of the upper lobe / Upper part of the lower lobe (Options A & B):** These areas are the classic sites for **Primary Tuberculosis** (the **Ghon focus**). Primary TB typically affects the subpleural regions of the mid-to-lower lung zones where ventilation is greatest during initial inhalation of the droplet nuclei [1]. * **Lower part of the lower lobe (Option C):** This area has the highest blood flow but the lowest $V/Q$ ratio and lower oxygen tension compared to the apex, making it an unfavorable site for the reactivation of aerobic mycobacteria. **3. Clinical Pearls for NEET-PG:** * **Simon Focus:** These are the initial nodules formed in the lung apices during the hematogenous seeding of primary TB, which later serve as the site for reactivation. * **Assmann Focus:** A term used for the infraclavicular lesion seen in secondary TB. * **Cavitation:** Secondary TB is characterized by caseous necrosis and **cavitation**, which is less common in primary TB (except in immunocompromised patients). * **Imaging:** On a Chest X-ray, look for "infiltrates or cavities in the apical/posterior segments of the upper lobe."

Question 608: Which of the following components is included in the CURB-65 score?

A. PaO2 less than 65 mm Hg
B. Coagulopathy
C. Severe azotemia (Correct Answer)
D. Base deficit (acidosis)

Explanation: The **CURB-65 score** is a validated clinical prediction rule used to determine the severity of Community-Acquired Pneumonia (CAP) and guide the decision for outpatient vs. inpatient management [1]. ### **Explanation of the Correct Answer** The "U" in CURB-65 stands for **Urea**. Specifically, a blood urea nitrogen (BUN) level **>19 mg/dL (7 mmol/L)** is considered a point [1]. This represents **azotemia**, which reflects systemic inflammation, dehydration, or secondary renal dysfunction due to sepsis. In the context of the options provided, "Severe azotemia" is the only component that aligns with the Urea criteria. ### **Analysis of Incorrect Options** * **A. PaO2 less than 65 mm Hg:** While hypoxia is critical in pneumonia, the CURB-65 score uses **Respiratory Rate (≥30/min)** as its respiratory marker, not PaO2 [1]. (Note: The "65" in the score refers to age, not oxygen levels). * **B. Coagulopathy:** This is a feature of the ATS/IDSA criteria for severe pneumonia (e.g., thrombocytopenia), but it is not a component of the CURB-65 score. * **D. Base deficit (acidosis):** While metabolic acidosis indicates poor perfusion, it is not part of this specific scoring system. ### **High-Yield Facts for NEET-PG** The CURB-65 mnemonic stands for: 1. **C**onfusion (new onset) 2. **U**rea >19 mg/dL (7 mmol/L) 3. **R**espiratory Rate ≥30 breaths/min 4. **B**lood Pressure (Systolic <90 mmHg or Diastolic ≤60 mmHg) 5. **65**: Age ≥65 years [1]. **Clinical Management Pearl:** * **Score 0-1:** Low risk; consider outpatient treatment. * **Score 2:** Moderate risk; consider short-stay inpatient or close outpatient monitoring. * **Score 3-5:** High risk; requires hospitalization (consider ICU for scores 4-5) [1].

Question 609: Which of the following is the initial management strategy for chronic obstructive pulmonary disease?

A. Aminophylline
B. Anticholinergics
C. Cessation of smoking (Correct Answer)
D. Oral steroids

Explanation: **Explanation:** The management of Chronic Obstructive Pulmonary Disease (COPD) focuses on symptom relief, reduction of exacerbations, and slowing disease progression. [1] **Why "Cessation of Smoking" is correct:** Smoking cessation is the **single most effective intervention** and the cornerstone of initial management. It is the only intervention (along with long-term oxygen therapy in hypoxic patients) proven to **slow the rate of decline in FEV1** and reduce mortality. [1], [2] According to the GOLD (Global Initiative for Chronic Obstructive Lung Disease) guidelines, every patient should be counseled on smoking cessation at every clinical encounter, regardless of the stage of the disease. [1] **Why the other options are incorrect:** * **Anticholinergics (B):** While inhaled bronchodilators (like Tiotropium or Ipratropium) are the mainstay for **symptomatic** management and are often the first-line pharmacological choice, they do not alter the natural history or the decline in lung function as effectively as smoking cessation. [1] * **Aminophylline (A):** This is a methylxanthine with a narrow therapeutic index and significant side effects. It is considered a third-line agent, used only when symptoms persist despite optimal inhaled therapy. [1] * **Oral Steroids (D):** These are used for managing acute exacerbations. Long-term use of oral steroids is discouraged in stable COPD due to a high risk-to-benefit ratio (e.g., osteoporosis, hyperglycemia, and infections). **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of COPD:** Smoking. * **Only interventions that improve survival:** Smoking cessation and Long-Term Oxygen Therapy (LTOT) for >15 hours/day. [2] * **Vaccination:** All COPD patients should receive the Influenza and Pneumococcal vaccines to prevent exacerbations. * **Diagnosis:** Post-bronchodilator FEV1/FVC ratio < 0.70 is diagnostic. [1]

Question 610: Which of the following is true regarding COPD?

A. FEV1/FVC ratio is less than 0.7 (Correct Answer)
B. FEV1/FVC ratio is increased
C. Residual Volume (RV) is decreased
D. Total Lung Capacity (TLC) is decreased

Explanation: ### Explanation **Correct Option: A (FEV1/FVC ratio < 0.7)** Chronic Obstructive Pulmonary Disease (COPD) is characterized by persistent airflow limitation. In obstructive lung diseases, the hallmark is a disproportionate decrease in the **Forced Expiratory Volume in 1 second (FEV1)** compared to the **Forced Vital Capacity (FVC)**. In this situation, the FEV1/FVC ratio is less than 70% [1]. According to the GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria, a **post-bronchodilator FEV1/FVC ratio of < 0.70** is the diagnostic requirement to confirm persistent airflow limitation. **Analysis of Incorrect Options:** * **B. FEV1/FVC ratio is increased:** An increased or normal ratio (> 0.7) is characteristic of **Restrictive Lung Diseases**, where both FEV1 and FVC decrease proportionately. * **C & D. RV and TLC are decreased:** In COPD, air trapping and hyperinflation occur due to loss of elastic recoil (emphysema) and small airway narrowing [3]. This leads to an **increase** in **Residual Volume (RV)**, **Functional Residual Capacity (FRC)**, and **Total Lung Capacity (TLC)**. Decreased lung volumes are seen in restrictive pathologies. **Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Spirometry is mandatory for diagnosis. * **Severity Grading:** While the ratio (<0.7) diagnoses COPD, the **FEV1 % predicted** determines the severity (GOLD stages I-IV). * **Pink Puffers vs. Blue Bloaters:** Emphysema (Type A) presents with hyperinflation and "pink" complexion; Chronic Bronchitis (Type B) presents with productive cough and cyanosis [2]. * **DLCO:** Decreased in Emphysema (due to alveolar destruction) but typically normal in Chronic Bronchitis and Asthma.

Practice by Chapter

Obstructive Airway Diseases (Asthma, COPD)

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Interstitial Lung Diseases

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Pulmonary Infections

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Pulmonary Vascular Diseases

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Pleural Diseases

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Sleep-Disordered Breathing

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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

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Lung Cancer Approach

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