Pulmonology — MCQs

A patient with known bronchial asthma presents with respiratory distress, a respiratory rate of 48/min, and can barely speak two words. Nebulized salbutamol was administered, after which the patient could speak a sentence, but SpO2 fell from 95% to 85%. What is the possible explanation for this fall in SpO2?

Q87Hard

A 77-year-old woman fell and fractured her ankle. She has spent most of her time in bed for the past 16 days. She develops sudden chest pain, dyspnea, and diaphoresis. On examination, she has left thigh swelling and tenderness. A chest CT shows areas of decreased attenuation in the right and left pulmonary arteries. A day later she has difficulty speaking. MR angiography shows focal occlusion of a left middle cerebral artery branch. Which of the following cardiac abnormalities is she most likely to have?

Q88Medium

Which of the following does NOT define severe ARDS according to the Berlin Definition of ARDS?

Q89Medium

Which of the following is true about pulmonary embolism?

Q90Medium

A 76-year-old man, a smoker since his teenage years, was admitted with a right lower lobe infiltrate strongly suggestive of pneumonia. Which of the following agents is not associated with adult community-acquired pneumonia?

Pulmonology Indian Medical PG Practice Questions and MCQs

Question 81: A 30-year-old male presented with fever, dry cough, and weight loss of 6 months duration. His chest X-ray shows a miliary pattern. Which of the following is NOT a likely diagnosis?

A. Tuberculosis
B. Wegener's granulomatosis (Correct Answer)
C. Fungal infection
D. Sarcoidosis

Explanation: ### Explanation The "miliary pattern" on a chest X-ray refers to numerous small (1–3 mm), discrete, rounded opacities distributed throughout both lungs, resembling millet seeds. **Why Wegener’s Granulomatosis (Granulomatosis with Polyangiitis) is the correct answer:** Wegener’s granulomatosis typically presents with **large nodules** (often >1 cm), which frequently undergo **cavitation** [2]. It also involves the upper respiratory tract (sinusitis, saddle nose deformity) and kidneys (GN) [2]. While it is a granulomatous disease, it does not typically present with a fine, diffuse miliary pattern. **Analysis of Incorrect Options:** * **Tuberculosis (TB):** This is the most common cause of a miliary pattern [1]. It occurs due to the hematogenous spread of *Mycobacterium tuberculosis*. The clinical triad of fever, weight loss, and dry cough in a young male is classic for miliary TB [1]. * **Fungal Infections:** Disseminated fungal infections, particularly **Histoplasmosis** and **Coccidioidomycosis**, can mimic miliary TB perfectly, especially in immunocompromised or endemic regions [2]. * **Sarcoidosis:** Stage II or III sarcoidosis can present with a miliary distribution of granulomas [3]. While bilateral hilar lymphadenopathy is more common, the "miliary sarcoid" variant is a recognized radiological presentation. **NEET-PG High-Yield Pearls:** * **Mnemonic for Miliary Shadows:** **"MIST"** — **M**elidiosis/Metastasis (Thyroid, RCC, Melanoma), **I**nfections (TB, Fungal), **S**arcoidosis/Silicosis, **T**alcosis. * **HRCT Finding:** In miliary TB, the nodules are typically **randomly distributed** (not centrilobular or perilymphatic). * **Differential Diagnosis:** If the nodules are predominantly in the lower lobes, consider hematogenous metastasis; if upper lobes, consider Silicosis or Extrinsic Allergic Alveolitis.

Question 82: A 50-year-old male presents with a 2 cm right solitary pulmonary nodule on chest X-ray with scalloped margins. The patient currently smokes 12 cigarettes per day. What is the risk of developing invasive carcinoma for such a patient?

A. Very low
B. Low
C. Intermediate (Correct Answer)
D. High

Explanation: The risk stratification of a Solitary Pulmonary Nodule (SPN) is determined by a combination of patient factors (age, smoking history) and radiological features (size, margins, calcification) [1]. **Why Intermediate is correct:** This patient falls into the **Intermediate Risk (5% to 65%)** category based on the following criteria: 1. **Age:** 50 years (Middle-aged patients are generally intermediate risk; <35 is low, >60 is high). 2. **Smoking History:** Current smoker (12 cigarettes/day). While any smoking increases risk, heavy smoking (>20/day) would lean toward high risk [2]. 3. **Size:** 2 cm (Nodules between 0.8 cm and 2.0 cm are typically classified as intermediate risk). 4. **Margins:** **Scalloped (lobulated) margins** are associated with an intermediate probability of malignancy. In contrast, smooth margins suggest benignity, while "spiculated" or "corona radiata" margins indicate high risk. **Why other options are incorrect:** * **Low Risk (<5%):** Typically seen in patients <35 years, non-smokers, with nodules <0.8 cm and smooth margins. [1] * **High Risk (>65%):** Seen in older patients (>60), heavy smokers, with nodules >2 cm and spiculated margins or upper lobe location. **NEET-PG High-Yield Pearls:** * **Calcification Patterns:** Benign patterns include Diffuse, Central, Popcorn (Hamartoma), and Laminated (Granuloma). Malignant patterns include Eccentric or Stippled. * **Doubling Time:** Malignant nodules typically double in volume between 20 to 400 days. Stability for >2 years suggests benignity [1]. * **Management:** For intermediate-risk nodules (0.8–2 cm), the next step is often a **PET-CT** or biopsy/resection, whereas low-risk nodules are monitored with serial CT scans.

Question 83: A patient on examination showed bronchial breathing and increased vocal resonance in the middle over the back just below the level of the 4th thoracic vertebra. This is called:

A. Ewart's sign
B. D'Espine sign (Correct Answer)
C. Hamman's sign
D. Hoffmann's sign

Explanation: ### Explanation **Correct Answer: B. D'Espine sign** **Understanding D'Espine Sign** D'Espine sign is a clinical finding used to detect **enlarged mediastinal lymph nodes** (often due to tuberculosis, sarcoidosis, or malignancy). Normally, when auscultating over the spine, the tracheal breath sounds and vocal resonance disappear below the level of the **bifurcation of the trachea** (typically the 4th thoracic vertebra in adults). * **The Mechanism:** Enlarged lymph nodes in the posterior mediastinum [1] act as a solid bridge, conducting sounds from the trachea/bronchi directly to the spinal column. * **The Finding:** If bronchial breathing or whispered pectoriloquy is heard **below the T4 level** (or T3 in children), the sign is considered positive. --- ### Analysis of Incorrect Options * **A. Ewart's sign:** This is an area of dullness, bronchial breathing, and bronchophony found at the **lower angle of the left scapula**. It is caused by a large **pericardial effusion** [1] compressing the base of the left lung. * **C. Hamman's sign:** Also known as "Hamman’s crunch," this refers to a clicking or crunching sound heard over the precordium synchronous with the heartbeat. It indicates **pneumomediastinum** (air in the mediastinum). * **D. Hoffmann's sign:** This is a **neurological sign** (not pulmonary). It is a finger flexor reflex elicited by flicking the nail of the middle finger; a positive response (flexion of the thumb/index finger) indicates upper motor neuron (UMN) lesions above the T1 level. --- ### NEET-PG High-Yield Pearls * **D'Espine Sign:** Think Mediastinal Lymphadenopathy (T4 level cutoff). * **Grocco’s Paravertebral Triangle:** A triangular area of dullness on the opposite side of a massive pleural effusion. * **Ellis S-Shaped Curve:** The characteristic upper border of percussion dullness in a pleural effusion. * **Kussmaul’s Sign:** Paradoxical rise in JVP on inspiration (seen in Constrictive Pericarditis, not to be confused with Kussmaul breathing).

Question 84: A patient presents with low-grade fever and weight loss. On examination, there is poor excursion of the right side of the chest, decreased tactile fremitus, dullness to percussion, and decreased breath sounds on the right. The trachea is deviated to the left. What is the most likely diagnosis?

A. Pneumothorax
B. Pleural effusion (Correct Answer)
C. Consolidated pneumonia
D. Atelectasis

Explanation: ### Explanation The clinical presentation points toward a **space-occupying lesion** in the pleural cavity. The key to solving respiratory physical exam questions lies in the combination of percussion notes, tactile vocal fremitus (TVF), and mediastinal (tracheal) position. **1. Why Pleural Effusion is Correct:** In pleural effusion, fluid accumulates between the visceral and parietal pleura [1]. This fluid acts as a physical barrier that: * **Dampens vibrations:** Leading to **decreased tactile fremitus**. * **Replaces air with liquid:** Resulting in a **stony dull** percussion note. * **Occupies space:** Increasing intrapleural pressure, which **pushes the trachea to the opposite side** (contralateral deviation). * **Blocks sound transmission:** Causing decreased or absent breath sounds. **2. Why the Other Options are Incorrect:** * **Pneumothorax:** While it causes contralateral tracheal shift and decreased breath sounds, the percussion note is **hyper-resonant** (due to air), not dull. * **Consolidated Pneumonia:** Consolidation (fluid in alveoli) improves sound conduction. Therefore, it presents with **increased tactile fremitus** and bronchial breath sounds. Crucially, there is usually **no tracheal deviation**. * **Atelectasis (Collapse):** This is a "restrictive" pathology where lung volume is lost. While it causes dullness and decreased breath sounds, it **pulls the trachea toward the same side** (ipsilateral deviation) due to negative pressure. **High-Yield Clinical Pearls for NEET-PG:** * **Tracheal Shift:** Pushed away in **Pleural Effusion** and **Tension Pneumothorax**; pulled toward in **Atelectasis** and **Pleural Fibrosis**. * **Percussion Note:** **Stony dull** is pathognomonic for pleural effusion. * **Tactile Fremitus:** Only increased in **Consolidation**; decreased in almost all other major pleural/pulmonary pathologies. * **Light’s Criteria:** Always remember this to differentiate between Exudative and Transudative effusions (Protein ratio >0.5, LDH ratio >0.6) [1].

Question 85: Which of the following organisms is unlikely to be found in the sputum of a patient with cystic fibrosis?

A. Haemophilus influenzae
B. Mycobacterium tuberculosis (Correct Answer)
C. Pseudomonas
D. Aspergillus fumigatus

Explanation: In Cystic Fibrosis (CF), the primary defect is in the **CFTR protein**, leading to thick, dehydrated mucus and impaired mucociliary clearance [1]. This creates a niche for specific opportunistic pathogens. **Why Mycobacterium tuberculosis (MTB) is the correct answer:** While patients with CF are highly susceptible to **Non-Tuberculous Mycobacteria (NTM)**, such as *Mycobacterium avium complex* (MAC) and *M. abscessus*, they do not have an increased predisposition to *Mycobacterium tuberculosis* compared to the general population. MTB is an obligate human pathogen spread via respiratory droplets and is not considered a typical "CF-colonizer." **Analysis of Incorrect Options:** * **Haemophilus influenzae:** This is often the **earliest** organism to colonize the lungs of children with CF, typically preceding Pseudomonas. * **Pseudomonas aeruginosa:** This is the **most common** pathogen in adult CF patients. It undergoes a phenotypic switch to a "mucoid" variant (alginate production), which is associated with a worse prognosis and chronic biofilm formation. * **Aspergillus fumigatus:** Fungal colonization is common due to thick mucus and frequent antibiotic use. It can lead to **Allergic Bronchopulmonary Aspergillosis (ABPA)**, a frequent complication in CF patients. **NEET-PG High-Yield Pearls:** * **Most common organism (Overall/Adults):** *Pseudomonas aeruginosa*. * **Most common organism (Infants/Children):** *Staphylococcus aureus*. * **Emerging highly resistant pathogen:** *Burkholderia cepacia* (associated with "Cepacia syndrome" – rapid clinical decline). * **Pancreatic Insufficiency:** Present in 85-90% of CF patients; look for fat-soluble vitamin deficiencies (A, D, E, K). * **Screening:** Immunoreactive Trypsinogen (IRT); **Gold Standard Diagnosis:** Sweat Chloride Test (>60 mmol/L).

Question 86: A patient with known bronchial asthma presents with respiratory distress, a respiratory rate of 48/min, and can barely speak two words. Nebulized salbutamol was administered, after which the patient could speak a sentence, but SpO2 fell from 95% to 85%. What is the possible explanation for this fall in SpO2?

A. Ventilation-perfusion mismatch due to increased dead space ventilation (Correct Answer)
B. Intrathoracic shunting
C. Due to salbutamol
D. Faulty oximeter

Explanation: ### Explanation The correct answer is **A. Ventilation-perfusion mismatch due to increased dead space ventilation.** **Mechanism:** In acute severe asthma, there is intense bronchoconstriction leading to areas of the lung with low ventilation-perfusion (V/Q) ratios [1]. When a potent bronchodilator like **Salbutamol (a β2-agonist)** is administered, it acts as a vasodilator. It reverses the compensatory **hypoxic pulmonary vasoconstriction** in poorly ventilated areas of the lung before it can fully achieve bronchodilation in those same areas. This leads to increased perfusion of poorly ventilated alveoli, worsening the **V/Q mismatch** and causing a transient drop in SpO2 [1]. This phenomenon is a classic paradoxical response seen during the initial treatment of status asthmaticus. **Analysis of Incorrect Options:** * **B. Intrathoracic shunting:** While V/Q mismatch is a form of "shunt-like" effect, true anatomical or physiological shunting (where blood bypasses ventilated alveoli entirely) is not the primary mechanism induced by salbutamol. * **C. Due to salbutamol:** While salbutamol *causes* the physiological change, the question asks for the *explanation* (the underlying pathophysiology). "Due to salbutamol" is an observation, not a medical explanation. * **D. Faulty oximeter:** The clinical improvement (ability to speak a sentence) indicates the drug is working, but the physiological side effect of V/Q mismatch is a well-documented medical occurrence, making a technical error less likely than a biological cause. **Clinical Pearls for NEET-PG:** * **Transient Hypoxemia:** Always administer supplemental oxygen alongside nebulized bronchodilators in acute asthma to counteract this transient drop in SpO2 [2]. * **The "Silent Chest":** A patient with asthma who stops wheezing but remains in distress is a medical emergency (impending respiratory failure). * **ABG in Asthma:** A "normal" PaCO2 (35-45 mmHg) in a patient with a high respiratory rate is an ominous sign, indicating respiratory muscle fatigue [2].

Question 87: A 77-year-old woman fell and fractured her ankle. She has spent most of her time in bed for the past 16 days. She develops sudden chest pain, dyspnea, and diaphoresis. On examination, she has left thigh swelling and tenderness. A chest CT shows areas of decreased attenuation in the right and left pulmonary arteries. A day later she has difficulty speaking. MR angiography shows focal occlusion of a left middle cerebral artery branch. Which of the following cardiac abnormalities is she most likely to have?

A. Atrial myxoma
B. Infective endocarditis
C. Nonbacterial thrombotic endocarditis
D. Patent foramen ovale (Correct Answer)

Explanation: ### Explanation **Correct Option: D. Patent foramen ovale (PFO)** **Concept: Paradoxical Embolism** The patient presents with a classic triad suggesting **Paradoxical Embolism**: 1. **Deep Vein Thrombosis (DVT):** Prolonged immobilization (16 days post-fracture) leading to thigh swelling and tenderness [3]. 2. **Pulmonary Embolism (PE):** Sudden chest pain, dyspnea, and CT findings of decreased attenuation (filling defects) in pulmonary arteries [2]. 3. **Systemic Embolism (Stroke):** Sudden difficulty speaking with MCA occlusion. For a venous thrombus to cause a stroke, it must bypass the pulmonary circulation and enter the systemic arterial system. This occurs via a **Right-to-Left shunt**. In the setting of a large PE, right-sided heart pressures rise acutely (acute pulmonary hypertension), which can force open a **Patent Foramen Ovale (PFO)**, allowing the thrombus to cross from the right atrium to the left atrium. --- ### Why Other Options are Incorrect: * **A. Atrial Myxoma:** While these can embolize systemically, they originate in the left atrium and would not explain the preceding pulmonary embolism or DVT. * **B. Infective Endocarditis:** Typically presents with fever, murmurs, and "warm" embolic phenomena. It does not explain the clear link between the leg fracture, DVT, and PE. * **C. Nonbacterial Thrombotic Endocarditis (NBTE):** Associated with advanced malignancy (Marantic endocarditis) or SLE. While it causes systemic emboli, it does not account for the pulmonary arterial filling defects. --- ### NEET-PG High-Yield Pearls: * **PFO Prevalence:** Present in approximately 25% of the general population; usually asymptomatic until a pressure gradient change occurs. * **Diagnosis:** The gold standard for detecting a shunt is a **Transesophageal Echocardiogram (TEE) with a Bubble Study** (agitated saline). * **Clinical Trigger:** Any patient with a DVT/PE [1] who subsequently develops a stroke or peripheral arterial occlusion must be evaluated for a paradoxical embolism. * **Cryptogenic Stroke:** PFO is a leading cause of "cryptogenic" strokes in younger patients.

Question 88: Which of the following does NOT define severe ARDS according to the Berlin Definition of ARDS?

A. PaO2/FiO2 < 200 (Correct Answer)
B. Acute onset within 1 week
C. Bilateral alveolar opacities on imaging
D. Non-cardiogenic pulmonary edema

Explanation: The **Berlin Definition (2012)** is the gold standard for diagnosing and grading the severity of Acute Respiratory Distress Syndrome (ARDS) [1]. ### 1. Why Option A is the Correct Answer The Berlin Definition categorizes ARDS severity based on the **PaO2/FiO2 (P/F) ratio** with a minimum PEEP of 5 cm H2O. According to these criteria: * **Mild ARDS:** P/F ratio 201 – 300 mmHg * **Moderate ARDS:** P/F ratio 101 – 200 mmHg * **Severe ARDS:** P/F ratio **≤ 100 mmHg** [1] Therefore, a P/F ratio < 200 defines *Moderate* ARDS, not *Severe* ARDS. ### 2. Analysis of Other Options * **Option B (Timing):** ARDS must have an **acute onset**, defined as occurring within **one week** of a known clinical insult or new/worsening respiratory symptoms [1]. * **Option C (Imaging):** Chest X-ray or CT scan must show **bilateral opacities** that are not fully explained by effusions, lobar/lung collapse, or nodules [1]. * **Option D (Origin of Edema):** The respiratory failure must not be fully explained by cardiac failure or fluid overload [1]. If no risk factor is present, an objective evaluation (e.g., echocardiography) is required to rule out **hydrostatic edema**. ### 3. High-Yield Clinical Pearls for NEET-PG * **PEEP Requirement:** To grade severity, a minimum Positive End-Expiratory Pressure (PEEP) or CPAP of **≥ 5 cm H2O** is mandatory [1]. * **Mortality:** As severity increases from Mild to Severe, mortality rates increase (approx. 27% to 45%). * **Management Tip:** For Severe ARDS (P/F < 150), high-yield interventions include **Prone Positioning** and **Neuromuscular Blockade** (early phase). * **Radiology:** The classic description is "white-out lungs" with air bronchograms.

Question 89: Which of the following is true about pulmonary embolism?

A. ECG shows a right ventricular strain pattern.
B. The PAO2-PaO2 difference is normal.
C. ECG also shows a typical S1Q3 T3 pattern.
D. Pulmonary embolism is not a medical emergency. (Correct Answer)

Explanation: **Explanation:** This question requires identifying the clinical and diagnostic features of Pulmonary Embolism (PE). **1. Why Option D is the "Correct" Answer (Contextual Analysis):** In the context of this specific question, Option D is marked as the "true" statement, which is clinically **paradoxical** as PE is a life-threatening emergency. however, in certain medical examinations, this may be a "trick" or a mislabeled option. If we evaluate the options strictly: * **Option A and C** are common findings but are **not universal** (low sensitivity) [1]. * **Option B** is physiologically incorrect [1]. * Therefore, if the question asks for the "true" statement and the others are definitively false or inconsistent, this highlights a potential error in the question source or a specific focus on "stable" PE. *Note: In standard clinical practice, PE is always a medical emergency.* **2. Analysis of Incorrect Options:** * **Option A & C (ECG Findings):** While **S1Q3T3** and **Right Ventricular Strain** (T-wave inversions in V1-V4) are classic, they are **not pathognomonic**. The most common ECG finding in PE is actually **Sinus Tachycardia** [1]. S1Q3T3 is seen in only ~20% of cases. * **Option B (A-a Gradient):** In PE, there is a V/Q mismatch leading to hypoxemia. Therefore, the **A-a gradient (PAO2-PaO2 difference) is typically increased**, not normal [1]. **3. High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Investigation:** CT Pulmonary Angiography (CTPA) [1]. * **Most Common Symptom:** Sudden onset dyspnea. * **Most Common Sign:** Tachypnea. * **Chest X-ray Signs:** Hampton’s Hump (wedge-shaped opacity) and Westermark sign (focal oligemia) [1]. * **Wells’ Score:** Used for clinical probability assessment. * **Treatment:** Hemodynamically unstable patients require **thrombolysis** (e.g., Alteplase), while stable patients are managed with **anticoagulation** (LMWH/Warfarin/NOACs) [1].

Question 90: A 76-year-old man, a smoker since his teenage years, was admitted with a right lower lobe infiltrate strongly suggestive of pneumonia. Which of the following agents is not associated with adult community-acquired pneumonia?

A. Streptococcus pneumoniae
B. Mycoplasma pneumoniae
C. Chlamydia trachomatis (Correct Answer)
D. Legionella pneumophila

Explanation: **Explanation:** The correct answer is **C. Chlamydia trachomatis**. **Why Chlamydia trachomatis is the correct answer:** *Chlamydia trachomatis* is a major cause of sexually transmitted infections (urethritis, PID) and neonatal infections (inclusion conjunctivitis and staccato cough pneumonia in infants). However, it is **not** a pathogen associated with community-acquired pneumonia (CAP) in adults. The species of *Chlamydia* that causes adult CAP is *Chlamydophila (Chlamydia) pneumoniae* [1]. **Analysis of Incorrect Options:** * **A. Streptococcus pneumoniae:** This is the **most common** cause of CAP across all age groups [1], typically presenting with lobar consolidation and "rusty" sputum [1]. * **B. Mycoplasma pneumoniae:** A common cause of "atypical pneumonia," frequently seen in younger adults but also prevalent in older populations. It often presents with extrapulmonary symptoms like bullous myringitis or erythema multiforme. * **D. Legionella pneumophila:** A significant cause of atypical pneumonia, especially in smokers and older adults [1]. It is often associated with contaminated water sources [1], GI symptoms (diarrhea), and hyponatremia. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of CAP:** *Streptococcus pneumoniae* [1]. * **Most common cause of atypical pneumonia:** *Mycoplasma pneumoniae*. * **Pneumonia in Smokers/COPD:** Increased risk of *Haemophilus influenzae*, *Moraxella catarrhalis*, and *Legionella* [1]. * **Alcoholics:** Increased risk of *Klebsiella pneumoniae* (currant jelly sputum) [1]. * **Post-Viral (Influenza) Pneumonia:** High incidence of *Staphylococcus aureus* [1]. * **Distinction:** *C. trachomatis* = Neonatal pneumonia; *C. pneumoniae* & *C. psittaci* = Adult pneumonia [1].

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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