Pulmonology — MCQs

Pulmonology Indian Medical PG Practice Questions and MCQs

Question 71: What is the definition of bronchiolithiasis?

A. Calcified lymph nodes eroding into a bronchus (Correct Answer)
B. A calcified foreign body in a bronchus
C. Lithium deposition in the bronchial wall
D. A hamartoma

Explanation: **Explanation:** **Bronchiolithiasis** is a clinical condition characterized by the presence of calcified material within the bronchial lumen or eroding through the bronchial wall. 1. **Why Option A is correct:** The most common cause of bronchiolithiasis is the **erosion of a calcified peribronchial lymph node** into the airway. This typically occurs following granulomatous infections, most notably **Tuberculosis** (highly relevant in the Indian context) or Histoplasmosis. Over time, these calcified nodes cause pressure necrosis of the bronchial wall, eventually migrating into the lumen. 2. **Why the other options are incorrect:** * **Option B:** While a "stone" is present in the bronchus, the term specifically refers to endogenous calcification (usually lymph nodes). A calcified foreign body is simply a foreign body; it does not meet the specific pathological definition of bronchiolithiasis. * **Option C:** This is a distractor based on the word "lith." Lithium has no role in bronchial wall deposition. * **Option D:** A hamartoma is a benign neoplasm containing "popcorn calcification," but it is a solid parenchymal tumor, not a mobile or eroding calcified node within the airway. **Clinical Pearls for NEET-PG:** * **Classic Symptom:** **Lithoptysis** (the coughing up of small, stone-like calcified material) is pathognomonic. * **Radiology:** CT scans show a calcified endobronchial nodule associated with signs of bronchial obstruction (e.g., distal atelectasis or obstructive pneumonia). * **Complications:** Recurrent pneumonia, hemoptysis (due to erosion into adjacent vessels), and bronchoesophageal fistulas. * **Management:** Bronchoscopic removal is often attempted, though surgery may be required if the stone is deeply embedded or causing severe complications.

Question 72: Type-II respiratory failure is associated with:

A. Flail chest (Correct Answer)
B. Pulmonary edema
C. Interstitial lung disease
D. ARDS

Explanation: **Explanation:** Respiratory failure is classified into two main types based on arterial blood gas (ABG) patterns: **Type-I (Hypoxemic)** and **Type-II (Hypercapnic).** [1] **Why Flail Chest is correct:** Type-II respiratory failure is characterized by **hypercapnia (PaCO₂ >45 mmHg)** and hypoxemia. [2] It occurs due to **pump failure**, where the respiratory system cannot adequately clear CO₂. [4] **Flail chest** (caused by multiple rib fractures) leads to paradoxical chest wall movement and severe pain, resulting in shallow breathing and mechanical instability. This reduces alveolar ventilation, leading to CO₂ retention. Other causes include neuromuscular disorders (GBS, Myasthenia Gravis) and CNS depression. **Why the other options are incorrect:** * **B, C, and D (Pulmonary Edema, ILD, and ARDS):** These conditions primarily involve **Type-I respiratory failure**. They are characterized by **ventilation-perfusion (V/Q) mismatch** or **diffusion defects** at the alveolar-capillary membrane. [2] In these states, oxygenation is impaired (Hypoxemia), but CO₂ can still be cleared effectively (often leading to low or normal PaCO₂ due to compensatory tachypnea) until the terminal stages of the disease. [4] **High-Yield Clinical Pearls for NEET-PG:** * **Type-I RF:** "Lung Failure" (Hypoxemia with normal/low PaCO₂). Examples: Pneumonia, PE, ARDS. [1] * **Type-II RF:** "Pump Failure" (Hypoxemia with High PaCO₂). Examples: COPD, Obesity Hypoventilation Syndrome, Flail Chest, Kyphoscoliosis. [3] * **Flail Chest Definition:** Fractures of ≥3 contiguous ribs in ≥2 places. * **Management Tip:** In Type-II failure due to mechanical issues like Flail Chest, the priority is pain control (epidural analgesia) and, if severe, mechanical ventilation to provide internal stabilization.

Question 73: All are causes of transudative pleural effusion, EXCEPT:

A. Cirrhosis
B. Nephrotic syndrome
C. Congestive heart failure
D. Bronchogenic carcinoma (Correct Answer)

Explanation: The classification of pleural effusion into transudate or exudate is based on **Light’s Criteria**, which reflects the underlying pathophysiology of fluid accumulation [1]. **Why Bronchogenic Carcinoma is the correct answer:** Bronchogenic carcinoma causes an **exudative pleural effusion**. This occurs because malignancy leads to direct pleural involvement, increased capillary permeability due to inflammatory cytokines, and lymphatic obstruction [1]. These mechanisms allow high-molecular-weight substances like proteins and LDH to leak into the pleural space. **Analysis of Incorrect Options (Causes of Transudate):** Transudates occur due to an imbalance in hydrostatic and oncotic pressures without primary disease of the pleural surface. * **Congestive Heart Failure (Option C):** The most common cause of transudative effusion. It occurs due to increased pulmonary capillary hydrostatic pressure. * **Cirrhosis (Option A):** Causes "Hepatic Hydrothorax" due to low plasma oncotic pressure (hypoalbuminemia) and the movement of ascitic fluid through diaphragmatic defects. * **Nephrotic Syndrome (Option B):** Results in a transudate due to severe proteinuria leading to decreased plasma oncotic pressure. **NEET-PG High-Yield Pearls:** * **Light’s Criteria for Exudate:** (Any one of the following) [1] 1. Pleural fluid protein/Serum protein ratio > 0.5 2. Pleural fluid LDH/Serum LDH ratio > 0.6 3. Pleural fluid LDH > 2/3rd the upper limit of normal serum LDH. * **Meigs’ Syndrome:** A classic triad of benign ovarian fibroma, ascites, and transudative pleural effusion. * **Pseudochylothorax:** Seen in chronic conditions like TB or Rheumatoid Arthritis; characterized by high cholesterol but low triglycerides.

Question 74: What is considered the best and most successful treatment for bronchial asthma?

A. Avoidance of antigen (Correct Answer)
B. Bronchodilators
C. Corticosteroids
D. Anticholinergics

Explanation: **Explanation:** **1. Why "Avoidance of Antigen" is correct:** Bronchial asthma is fundamentally a chronic inflammatory airway disease characterized by bronchial hyperresponsiveness to various triggers [1]. In many patients (particularly those with extrinsic/atopic asthma), the underlying pathophysiology is driven by a Type I hypersensitivity reaction to specific environmental allergens (antigens). While pharmacological agents manage symptoms and inflammation [2], **avoidance of the offending antigen** is the only "preventative" strategy that addresses the root cause. By eliminating the trigger, the inflammatory cascade is never initiated, making it the most successful long-term management strategy to achieve complete remission and prevent airway remodeling. **2. Why the other options are incorrect:** * **Bronchodilators (B):** These (e.g., SABAs like Salbutamol) are the mainstay for **acute symptomatic relief** (rescue therapy) [3]. They reverse bronchoconstriction but do not treat the underlying chronic inflammation. * **Corticosteroids (C):** These are the most effective **pharmacological** treatments for controlling inflammation [4]. However, they are considered "management" rather than a "cure" or "best treatment" compared to total trigger elimination, as they carry potential side effects with long-term use. * **Anticholinergics (D):** Agents like Ipratropium bromide are used as add-on therapies in acute exacerbations or for patients intolerant to beta-agonists [3]. They are less effective than corticosteroids and bronchodilators in routine asthma care. **3. NEET-PG High-Yield Pearls:** * **Gold Standard Diagnosis:** Spirometry showing reversible airway obstruction (increase in FEV1 >12% and >200ml after bronchodilator). * **Drug of Choice (Maintenance):** Inhaled Corticosteroids (ICS) are the cornerstone of long-term pharmacological control [2]. * **Drug of Choice (Acute Attack):** Inhaled Short-Acting Beta-2 Agonists (SABA). * **Pathology:** Look for **Curschmann spirals** (mucus plugs) and **Charcot-Leyden crystals** (eosinophil breakdown products) in sputum.

Question 75: When is central cyanosis not present, given the total hemoglobin and reduced hemoglobin levels (in gm/dL) respectively?

A. 10.9 & 4.1 (Correct Answer)
B. 10.9 & 5.1
C. 8.9 & 4.1
D. All of the above

Explanation: **Explanation:** The fundamental principle behind the clinical detection of **central cyanosis** is the absolute concentration of **reduced (deoxygenated) hemoglobin** in the capillary bed. [1] 1. **The Underlying Concept:** Cyanosis becomes clinically apparent only when the concentration of reduced hemoglobin in the capillaries exceeds **5 g/dL**. [1] It is important to note that cyanosis depends on the *absolute amount* of deoxygenated hemoglobin, not the ratio of oxygenated to deoxygenated hemoglobin. 2. **Why Option A is Correct:** In Option A, the reduced hemoglobin is **4.1 g/dL**. Since this value is **less than the threshold of 5 g/dL**, central cyanosis will **not** be visible, regardless of the total hemoglobin level (10.9 g/dL). 3. **Analysis of Incorrect Options:** * **Option B (10.9 & 5.1):** The reduced hemoglobin is 5.1 g/dL. Since this is $>5$ g/dL, cyanosis will be present. * **Option C (8.9 & 4.1):** While 4.1 g/dL is below the threshold, this option is incorrect because Option A is the specific scenario provided where cyanosis is absent. (Note: In severe anemia, cyanosis is harder to detect because the total hemoglobin may be so low that reaching 5 g/dL of reduced hemoglobin would be fatal). * **Option D:** Incorrect as only Option A meets the criteria for the absence of cyanosis. **High-Yield Clinical Pearls for NEET-PG:** * **Anemia:** In patients with severe anemia (Hb < 7 g/dL), cyanosis may not appear even in states of severe hypoxia because the total Hb is insufficient to produce 5 g/dL of reduced Hb. [1] * **Polycythemia:** Patients with high Hb levels develop cyanosis much more easily (at higher oxygen saturation levels) because they reach the 5 g/dL threshold faster. * **Site of Examination:** Central cyanosis is best assessed in the **tongue and mucous membranes** (highly vascular, not affected by cold).

Question 76: What is true about primary pulmonary hypoventilation?

A. Does not respond to chemical stimuli (Correct Answer)
B. Hypocapnia and normal PaO2
C. Common in children
D. Respiratory alkalosis is diagnostic

Explanation: **Primary Alveolar Hypoventilation (Ondine’s Curse)** is a rare disorder characterized by an idiopathic failure of the autonomic control of breathing despite normal lung mechanics and neuromuscular function [1]. ### **Explanation of the Correct Answer** **Option A** is correct because the hallmark of this condition is a **blunted or absent ventilatory response to chemical stimuli**, specifically hypercapnia ($CO_2$ retention) and hypoxia ($O_2$ deficiency) [2]. While these patients can breathe normally when awake (using voluntary cortical control), they "forget" to breathe during sleep because the brainstem chemoreceptors fail to trigger a respiratory response to rising $PaCO_2$ levels [1]. ### **Analysis of Incorrect Options** * **Option B:** Incorrect. Because the patient is hypoventilating, they develop **Hypercapnia** (elevated $PaCO_2$) and **Hypoxemia** (low $PaO_2$), not hypocapnia [2]. * **Option C:** Incorrect. While a congenital form exists (CCHS), primary pulmonary hypoventilation is traditionally described as a rare condition most commonly diagnosed in **males in their 3rd or 4th decade** of life. * **Option D:** Incorrect. Chronic hypoventilation leads to $CO_2$ retention, resulting in **Respiratory Acidosis** (with compensatory metabolic alkalosis), not respiratory alkalosis. ### **NEET-PG High-Yield Pearls** * **Clinical Presentation:** Often presents with daytime somnolence, morning headaches, and polycythemia. * **Diagnosis of Exclusion:** It is only diagnosed after ruling out primary lung disease, chest wall deformities (like kyphoscoliosis), and neuromuscular disorders [1]. * **PFT Findings:** Pulmonary function tests are typically **normal** (normal FEV1, FVC, and lung volumes), which distinguishes it from obstructive or restrictive lung diseases [1]. * **Management:** The treatment of choice is usually mechanical ventilation (CPAP/BiPAP) or diaphragm pacing.

Question 77: Which of the following defines Acute Respiratory Distress Syndrome (ARDS)?

A. PaO2/FiO2 < 300
B. Acute onset
C. PCWP > 18 mm Hg (Correct Answer)
D. Bilateral alveolar infiltrates

Explanation: The diagnosis of **Acute Respiratory Distress Syndrome (ARDS)** is based on the **Berlin Criteria** [1]. To correctly answer this question, one must identify which option is **NOT** part of the definition. In many competitive exams like NEET-PG, "Which of the following defines..." can imply "Which of the following is an exclusion criterion or a specific parameter." **Why Option C is the Correct Answer (The Exception):** According to the Berlin Criteria, ARDS is characterized by **non-cardiogenic pulmonary edema** [1]. This means the respiratory failure must not be fully explained by heart failure or fluid overload [1]. A **Pulmonary Capillary Wedge Pressure (PCWP) > 18 mm Hg** suggests a cardiogenic cause (Left Ventricular Failure). Therefore, for a diagnosis of ARDS, the PCWP should ideally be **≤ 18 mm Hg** (if measured), or there should be no clinical evidence of left atrial hypertension. **Analysis of Other Options (Inclusion Criteria):** * **Option A (PaO2/FiO2 < 300):** This is a core requirement. ARDS is graded by severity: Mild (200–300), Moderate (100–200), and Severe (< 100). * **Option B (Acute onset):** The symptoms must manifest within **one week** of a known clinical insult or new/worsening respiratory symptoms [1]. * **Option D (Bilateral alveolar infiltrates):** Chest imaging (X-ray or CT) must show bilateral opacities that are not fully explained by effusions, collapse, or nodules [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Pathology:** The hallmark of ARDS is **Diffuse Alveolar Damage (DAD)** and the formation of **Hyaline membranes**. * **Ventilation Strategy:** Use **Low Tidal Volume Ventilation (6 mL/kg)** to prevent volutrauma (the "ARSDnet" protocol). * **Refractory Hypoxemia:** ARDS is characterized by hypoxemia that does not respond significantly to increased FiO2 due to intrapulmonary shunting [2]. * **Prone Positioning:** Recommended for severe ARDS (PaO2/FiO2 < 150) to improve V/Q matching.

Question 78: What is the cause of transudate pleural effusion?

A. Nephrotic syndrome (Correct Answer)
B. Tuberculosis
C. Pneumonia
D. Pulmonary infarction

Explanation: **Explanation:** Pleural effusions are classified into transudates and exudates based on **Light’s Criteria**, which reflects the underlying pathophysiology of fluid accumulation. [1] **1. Why Nephrotic Syndrome is Correct:** Transudative effusions occur due to an imbalance in hydrostatic and oncotic pressures without primary pleural disease. In **Nephrotic Syndrome**, massive proteinuria leads to **hypoalbuminemia**. This decreases the **plasma oncotic pressure**, allowing fluid to leak from the capillaries into the pleural space. Other classic causes of transudate include Congestive Heart Failure (increased hydrostatic pressure) and Liver Cirrhosis. [1] **2. Why the Other Options are Incorrect:** * **Tuberculosis (B) & Pneumonia (C):** These are inflammatory/infectious processes. Inflammation increases capillary permeability and impairs lymphatic drainage, leading to an **exudative** effusion (high protein and LDH). [1] * **Pulmonary Infarction (D):** This typically occurs due to Pulmonary Embolism. The resulting tissue ischemia and inflammation lead to an **exudative** effusion, which is often hemorrhagic. [1] **High-Yield Clinical Pearls for NEET-PG:** * **Light’s Criteria for Exudate (Any one of the following):** 1. Pleural fluid protein/Serum protein ratio **> 0.5** 2. Pleural fluid LDH/Serum LDH ratio **> 0.6** 3. Pleural fluid LDH **> 2/3rd** the upper limit of normal serum LDH. * **Most common cause of Transudate:** Congestive Heart Failure (usually bilateral). * **Most common cause of Exudate:** Bacterial pneumonia (Parapneumonic effusion) and Malignancy. [1] * **Pseudochylothorax:** Seen in chronic TB or Rheumatoid Arthritis (high cholesterol, low triglycerides).

Question 79: Which of the following are characteristic findings in pleural effusion?

A. Horizontal fluid level (Correct Answer)
B. Low lung volume
C. Muffled heart sounds
D. Decreased chest movements

Explanation: ### Explanation **Correct Option: A. Horizontal fluid level** In a standard pleural effusion, fluid accumulates in the dependent part of the pleural space, typically forming a curved upper border known as the **Ellis-Damoiseau line** (meniscus sign). However, a **horizontal (straight) fluid level** is a classic radiological hallmark when there is both air and fluid in the pleural space, known as a **hydropneumothorax**. In the context of NEET-PG questions, "horizontal fluid level" is frequently used to describe the appearance of fluid collection in the chest on an upright X-ray, distinguishing it from the parenchymal opacities of pneumonia. **Analysis of Incorrect Options:** * **B. Low lung volume:** While a massive effusion can cause compressive atelectasis, "low lung volume" is more characteristic of restrictive lung diseases (like ILD) or poor inspiratory effort rather than a diagnostic feature of effusion itself. * **C. Muffled heart sounds:** This is a classic sign of **pericardial effusion** (Beck’s Triad), not pleural effusion. In pleural effusion, breath sounds are diminished, but heart sounds are usually normal unless the effusion is massive and left-sided. * **D. Decreased chest movements:** While chest expansion may be reduced on the affected side, this is a non-specific finding seen in pneumonia, pneumothorax, and collapse. The presence of a fluid level is a more specific radiological characteristic. **High-Yield Clinical Pearls for NEET-PG:** * **Physical Exam:** Stony dull percussion note (most specific sign), decreased tactile vocal fremitus, and absent breath sounds. * **Light’s Criteria:** Used to differentiate Exudate from Transudate (Protein ratio >0.5, LDH ratio >0.6, or pleural LDH >2/3rd upper limit of normal). * **Imaging:** The earliest sign on a PA view X-ray is the **obliteration of the costophrenic angle** (requires ~200ml of fluid). Lateral decubitus films can detect as little as 5–10ml.

Question 80: The pleural fluid LDH / serum LDH ratio is _____ in exudative pleural effusion.

A. > 0.3
B. > 0.5
C. > 0.6 (Correct Answer)
D. > 0.8

Explanation: This question tests your knowledge of **Light’s Criteria**, which is the gold standard for differentiating between transudative and exudative pleural effusions. [1] ### **Explanation of the Correct Answer** According to Light’s Criteria, a pleural effusion is classified as an **exudate** if it meets at least one of the following three criteria: 1. **Pleural fluid protein / Serum protein ratio > 0.5** 2. **Pleural fluid LDH / Serum LDH ratio > 0.6** 3. **Pleural fluid LDH > 2/3rd the upper limit of normal (ULN) for serum LDH** Exudates are caused by inflammation, malignancy, or infection, which increases capillary permeability, allowing larger molecules like LDH (Lactate Dehydrogenase) and proteins to leak into the pleural space. [1] Therefore, a ratio of **> 0.6** is the established diagnostic threshold. ### **Analysis of Incorrect Options** * **Option A (> 0.3):** This value is too low and lacks diagnostic specificity for exudates. * **Option B (> 0.5):** This is the threshold for the **Protein ratio**, not the LDH ratio. Confusing these two is a common pitfall in the exam. * **Option D (> 0.8):** While a ratio of 0.8 is technically exudative, it is not the standard diagnostic cutoff defined by Light’s Criteria. ### **High-Yield Clinical Pearls for NEET-PG** * **Transudates:** Occur due to imbalances in hydrostatic/oncotic pressure (e.g., CHF, Nephrotic syndrome, Cirrhosis). All three Light’s criteria must be negative. * **The "False Exudate" Rule:** In patients on diuretics for CHF, transudates may falsely appear as exudates due to protein concentration. In such cases, check the **Serum-Effusion Protein Gradient**; if it is **> 3.1 g/dL**, it is likely a transudate. * **Very Low Glucose (< 60 mg/dL):** Suggests Rheumatoid arthritis, Empyema, Malignancy, or Tuberculosis. [1] * **High Amylase:** Suggests Pancreatitis or Esophageal rupture. [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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