Pulmonology — MCQs

Pulmonology Indian Medical PG Practice Questions and MCQs

Question 91: What is the best and earliest bedside clinical sign of respiratory pump failure?

A. Use of intercostal muscles (accessory muscles of respiration)
B. Paradoxical respiratory motions (abdominal respiration or paradox) (Correct Answer)
C. Tachypnea
D. Cyanosis

Explanation: **Explanation:** The **respiratory pump** consists of the chest wall, respiratory muscles (primarily the diaphragm), and the neural pathways controlling them. Respiratory pump failure occurs when these components can no longer sustain the work of breathing, leading to alveolar hypoventilation and hypercapnia [1]. **Why Paradoxical Respiration is the Correct Answer:** **Paradoxical respiratory motion** (specifically abdominal paradox) is the hallmark clinical sign of diaphragmatic fatigue and impending pump failure. Normally, the abdomen moves outward during inspiration as the diaphragm contracts and descends. In pump failure, the diaphragm becomes exhausted and is pulled upward into the chest by the negative pressure generated by accessory muscles. This causes the **abdomen to move inward during inspiration**, which is the most specific and earliest bedside indicator that the "pump" is failing. **Analysis of Incorrect Options:** * **A. Use of accessory muscles:** While a sign of increased work of breathing, it often precedes actual pump failure. It indicates respiratory distress but not necessarily the point of exhaustion/failure. * **C. Tachypnea:** This is the most common and earliest sign of general respiratory distress (e.g., impaired gas exchange), but it is non-specific and does not specifically pinpoint "pump" failure. * **D. Cyanosis:** This is a late and unreliable sign. It indicates severe hypoxemia but occurs long after the compensatory mechanisms of the respiratory pump have failed. **High-Yield Clinical Pearls for NEET-PG:** * **Respiratory Pump Failure** = Hypercapnic Respiratory Failure (Type II) [1]. * **Lung Parenchymal Failure** = Hypoxemic Respiratory Failure (Type I) [1]. * **Sequence of Fatigue:** Tachypnea → Respiratory Alternans (alternating between diaphragmatic and accessory muscle use) → Abdominal Paradox → Respiratory Arrest. * **Gold Standard for Diagnosis:** Arterial Blood Gas (ABG) showing elevated $PaCO_2$ and respiratory acidosis [2].

Question 92: A high amylase level in pleural fluid suggests which diagnosis?

A. Tuberculosis
B. Malignancy (Correct Answer)
C. Rheumatoid arthritis
D. Pulmonary infarction

Explanation: Pleural fluid amylase is considered elevated when it exceeds the upper limit of normal for serum amylase or when the pleural fluid-to-serum amylase ratio is >1.0. **Why Malignancy is Correct:** Malignancy is one of the most common causes of amylase-rich pleural effusions. It is typically associated with **Adenocarcinoma** of the lung or ovary. In these cases, the amylase is usually of the **salivary isoenzyme** type, produced directly by the tumor cells themselves. [1] **Analysis of Incorrect Options:** * **Tuberculosis (A):** TB effusions are characterized by high protein (exudate), high ADA (Adenosine Deaminase) levels, and a lymphocytic predominance, but not typically high amylase. * **Rheumatoid Arthritis (C):** RA effusions are classic for having **very low glucose** levels (<30 mg/dL), high LDH, and low pH, but amylase levels remain normal. [1] * **Pulmonary Infarction (D):** This usually results in a bloody or serosanguinous exudative effusion with high mesothelial cells, but it does not involve amylase elevation. [1] **NEET-PG High-Yield Pearls:** The differential diagnosis for high amylase in pleural fluid is narrow and high-yield: 1. **Acute Pancreatitis:** (Most common cause; involves **pancreatic isoenzyme**; usually left-sided). [2] 2. **Esophageal Rupture (Boerhaave Syndrome):** (Highest levels of amylase; **salivary isoenzyme** due to swallowed saliva leaking into the mediastinum/pleura). [1] 3. **Malignancy:** (Salivary isoenzyme; primarily lung adenocarcinoma). 4. **Chronic Pancreatic Pseudocyst:** (Can cause massive pleural effusions). *Mnemonic: Remember "PEM" for high amylase — Pancreatitis, Esophageal rupture, Malignancy.*

Question 93: The complication least likely to occur in a case of chronic bronchitis is:

A. Pulmonary hypertension
B. Spontaneous pneumothorax (Correct Answer)
C. Respiratory acidosis
D. Polycythemia

Explanation: **Explanation:** Chronic bronchitis is characterized by chronic airway inflammation, mucus hypersecretion, and airway narrowing. To identify the "least likely" complication, we must distinguish its pathophysiology from that of emphysema. **Why Spontaneous Pneumothorax is the correct answer:** Spontaneous pneumothorax is a classic complication of **emphysema**, not chronic bronchitis [1]. In emphysema, the destruction of alveolar walls leads to the formation of subpleural blebs or bullae. When these rupture, air enters the pleural space. While chronic bronchitis and emphysema often coexist in COPD, the specific pathological hallmark of chronic bronchitis (mucus gland hyperplasia) does not inherently cause bleb formation or lung collapse. **Analysis of Incorrect Options:** * **Pulmonary Hypertension:** Chronic bronchitis leads to chronic alveolar hypoxia. This triggers **hypoxic pulmonary vasoconstriction**, which increases pulmonary vascular resistance, eventually leading to pulmonary hypertension and Cor Pulmonale. * **Respiratory Acidosis:** Narrowed airways and mucus plugging lead to ventilation-perfusion (V/Q) mismatch and CO2 retention (hypercapnia) [1]. Chronic CO2 retention results in respiratory acidosis. * **Polycythemia:** Persistent hypoxemia stimulates the kidneys to release erythropoietin, which increases red blood cell production (secondary polycythemia) to improve oxygen-carrying capacity [1]. This is why chronic bronchitis patients are often termed "Blue Bloaters." **NEET-PG High-Yield Pearls:** * **Blue Bloaters (Chronic Bronchitis):** Characterized by hypoxia, hypercapnia, early onset of Cor Pulmonale, and polycythemia [1]. * **Pink Puffers (Emphysema):** Characterized by near-normal oxygenation (initially), hyperventilation, and a high risk of **pneumothorax** due to bullae. * **Reid Index:** Increased (>0.4) in chronic bronchitis (ratio of mucous gland thickness to bronchial wall thickness).

Question 94: The CURB-65 score is used in pneumonia to assess which of the following?

A. Severity (Correct Answer)
B. Complication
C. Etiology
D. Prognosis

Explanation: **Explanation:** The **CURB-65 score** is a validated clinical prediction rule used to determine the **severity** of Community-Acquired Pneumonia (CAP) [1]. Its primary purpose is to guide clinical decision-making regarding the site of care (outpatient vs. inpatient vs. ICU). **Why Severity is Correct:** The score assesses the physiological impact of pneumonia on the patient. By calculating a score from 0 to 5, clinicians can stratify patients into low, moderate, or high-risk categories [1]. A higher score indicates greater physiological derangement and a higher risk of mortality, directly reflecting the severity of the disease. **Why Other Options are Incorrect:** * **Complication:** While a high CURB-65 score may correlate with complications (like empyema or sepsis), the score itself does not identify or diagnose specific complications. * **Etiology:** The score is independent of the causative pathogen (e.g., *S. pneumoniae* vs. *Legionella*). It measures the host's response, not the microbial cause. * **Prognosis:** While CURB-65 is a strong predictor of 30-day mortality (prognostic value), its primary clinical application in guidelines (like BTS/IDSA) is to assess **severity** to decide on immediate management and hospitalization. **High-Yield Clinical Pearls for NEET-PG:** * **Components of CURB-65:** [1] 1. **C**onfusion (new onset) 2. **U**rea > 7 mmol/L (19 mg/dL) 3. **R**espiratory Rate ≥ 30/min 4. **B**lood Pressure (Systolic < 90 or Diastolic ≤ 60 mmHg) 5. **65** (Age ≥ 65 years) * **Management Guide:** [1] * Score **0-1**: Low risk; consider outpatient treatment. * Score **2**: Moderate risk; consider short-stay inpatient or supervised outpatient. * Score **3-5**: Severe pneumonia; urgent hospitalization (consider ICU for 4-5). * **CRB-65:** A modified version used in primary care when urea levels are unavailable.

Question 95: Which of the following is true about asthma?

A. Increasing incidence day by day
B. Allergic asthma is common in older patients
C. Increase in IgE in idiosyncratic asthma (Correct Answer)
D. Bronchoconstriction

Explanation: ### Explanation Asthma is a chronic inflammatory airway disease characterized by reversible airflow obstruction and bronchial hyperresponsiveness. **Why Option C is Correct:** Asthma is broadly classified into **Extrinsic (Atopic)** and **Intrinsic (Idiosyncratic/Non-atopic)** types. While extrinsic asthma is driven by Type I hypersensitivity to external allergens, **idiosyncratic asthma** typically occurs in older patients with no family history or positive skin tests. However, research indicates that even in idiosyncratic asthma, there is often a local or systemic **increase in IgE levels** and eosinophilic inflammation, suggesting a similar underlying mucosal inflammatory pathway despite the absence of identifiable external triggers. **Analysis of Incorrect Options:** * **Option A:** While asthma prevalence is high, the statement "increasing day by day" is a generalized epidemiological trend rather than a defining pathophysiological or clinical "truth" tested in this context. * **Option B:** Allergic (atopic) asthma is most common in **children and young adults**. In contrast, late-onset asthma is more frequently non-allergic (idiosyncratic). * **Option D:** While bronchoconstriction is a feature of an asthma attack, it is a **physiological manifestation** rather than a defining "true statement" in the context of the disease's classification or immunopathology compared to the specific immunological finding in Option C. **High-Yield NEET-PG Pearls:** * **Samter’s Triad:** Aspirin sensitivity, Nasal polyps, and Asthma (often seen in intrinsic cases). * **Diagnosis:** Gold standard is Spirometry showing reversibility (FEV1 increase >12% and >200ml after bronchodilator). * **Charcot-Leyden Crystals:** Formed from eosinophil lysophospholipase; found in the sputum of asthmatics. * **Curschmann Spirals:** Whorled mucus plugs found in subepithelial mucous gland ducts.

Question 96: A young patient presented with features of pneumonia, X-ray showed a lung abscess and a bulging fissure. Which of the following is the most likely causative organism?

A. Staphylococcus
B. Klebsiella (Correct Answer)
C. Pneumocystis carinii infection
D. Cytomegalovirus (CMV)

Explanation: ### Explanation The clinical presentation of pneumonia associated with a **lung abscess** and a **bulging fissure** on chest X-ray is a classic diagnostic hallmark for **Klebsiella pneumoniae**. **1. Why Klebsiella is correct:** * **Bulging Fissure Sign:** *Klebsiella* pneumonia is characterized by a heavy, thick, mucoid (currant-jelly) inflammatory exudate. This voluminous exudate causes the affected lobe to expand, resulting in the downward displacement or "bulging" of the adjacent interlobar fissure. * **Tissue Necrosis:** It is a necrotizing pneumonia, frequently leading to cavitation and lung abscess formation, especially in patients with predisposing factors like alcoholism or diabetes mellitus [1]. **2. Why other options are incorrect:** * **Staphylococcus aureus:** While it commonly causes lung abscesses and pneumatoceles (especially post-influenza), it does not typically produce the voluminous exudate required to cause a bulging fissure [1]. * **Pneumocystis jirovecii (formerly carinii):** Typically presents as bilateral, diffuse interstitial infiltrates ("ground-glass opacities") in immunocompromised patients. It does not cause lobar consolidation or bulging fissures. * **Cytomegalovirus (CMV):** Usually presents as viral interstitial pneumonitis with diffuse involvement rather than localized abscesses or lobar expansion. **3. High-Yield Clinical Pearls for NEET-PG:** * **Classic Sputum:** "Currant-jelly" sputum (thick and blood-tinged). * **Risk Groups:** Most common in chronic alcoholics, diabetics, and the elderly [1]. * **Radiology:** Predilection for the **upper lobes** (specifically the right upper lobe). * **Friedländer’s Bacillus:** An older name for *Klebsiella pneumoniae*.

Question 97: All of the following are seen in Kartagener syndrome except?

A. Bronchiectasis
B. Azoospermia (Correct Answer)
C. Situs inversus
D. Sinusitis

Explanation: **Explanation:** Kartagener syndrome is a subset of **Primary Ciliary Dyskinesia (PCD)**, an autosomal recessive disorder characterized by a structural defect in the **dynein arms** of cilia. This leads to impaired mucociliary clearance and ciliary immotility throughout the body [1]. **Why Azoospermia is the correct answer (the "Except"):** In Kartagener syndrome, males typically present with **infertility**, but not azoospermia. The sperm count is usually normal, but the sperm are **immotile** because the flagella (which share the same microtubular structure as cilia) cannot beat. Azoospermia (absence of sperm) is characteristic of conditions like Cystic Fibrosis (due to congenital bilateral absence of the vas deferens) or obstructive pathologies, not PCD [2]. **Analysis of Incorrect Options:** * **Situs Inversus:** This is the hallmark of Kartagener syndrome (seen in 50% of PCD cases). It occurs because ciliary motion is essential for the normal left-right rotation of internal organs during embryonic development. * **Bronchiectasis:** Chronic failure of the "mucociliary escalator" leads to recurrent lower respiratory tract infections, eventually causing permanent dilation of the bronchi [1]. * **Sinusitis:** Impaired clearance of mucus from the paranasal sinuses leads to chronic inflammation and recurrent sinusitis [1]. **High-Yield Clinical Pearls for NEET-PG:** * **The Triad:** Kartagener syndrome is defined by the triad of **Situs inversus, Bronchiectasis, and Sinusitis.** [1] * **Diagnosis:** The screening test of choice is the **Saccharin test** (delayed transit time), while the gold standard is **Electron Microscopy** showing dynein arm defects. * **Female Infertility:** Females also face reduced fertility due to impaired ciliary action in the fallopian tubes, increasing the risk of ectopic pregnancies. * **Dextrocardia:** Often the first clue on a chest X-ray in these patients.

Question 98: Pulmonary hypertension in COPD is due to?

A. Constriction of pulmonary vessels (Correct Answer)
B. Hypoxia
C. Interstitial fibrosis
D. Bronchoconstriction

Explanation: The primary mechanism for the development of Pulmonary Hypertension (PH) in COPD is **Hypoxic Pulmonary Vasoconstriction (HPV)**. In COPD, chronic alveolar hypoxia triggers the smooth muscles in the pulmonary arterioles to constrict. This is a physiological compensatory mechanism intended to divert blood flow away from poorly ventilated areas to better-ventilated ones (improving V/Q matching). However, when hypoxia is generalized, it leads to widespread **constriction of pulmonary vessels**, increasing pulmonary vascular resistance and resulting in PH [1]. **Analysis of Options:** * **A. Constriction of pulmonary vessels (Correct):** This is the direct hemodynamic cause of increased pressure [1]. Chronic constriction eventually leads to vascular remodeling (intimal hyperplasia and smooth muscle hypertrophy), making the PH permanent. * **B. Hypoxia (Incorrect):** While hypoxia is the *trigger* or the underlying stimulus, the question asks for the mechanism *due to* which PH occurs. Hypoxia causes PH *via* the constriction of vessels. * **C. Interstitial fibrosis (Incorrect):** This is the hallmark of Restrictive Lung Diseases (like IPF), not COPD (which is an obstructive disease characterized by alveolar destruction/emphysema) [3]. * **D. Bronchoconstriction (Incorrect):** This refers to the narrowing of the airways, which causes airflow obstruction but does not directly increase pulmonary arterial pressure. **Clinical Pearls for NEET-PG:** * **Cor Pulmonale:** PH in COPD eventually leads to right ventricular hypertrophy and failure, known as Cor Pulmonale. * **ECG Findings:** Look for 'P-pulmonale' (tall, peaked P waves in lead II) and right axis deviation. * **Management:** Long-term oxygen therapy (LTOT) is the only intervention proven to slow the progression of PH in COPD by reducing hypoxic vasoconstriction [2].

Question 99: Right hemithorax with right side shift of the mediastinum is due to which of the following conditions?

A. Collapse of the right lung (Correct Answer)
B. Right-sided hemothorax
C. Right-sided hydrothorax
D. Bronchiectasis

Explanation: **Explanation:** The direction of mediastinal shift is a critical diagnostic clue in evaluating an opaque hemithorax on a chest X-ray. The fundamental principle is whether the pathology **pulls** or **pushes** the mediastinum. **1. Why Option A is Correct:** **Collapse (Atelectasis)** of the right lung leads to a significant loss of lung volume. This creates negative intrathoracic pressure on the affected side, which acts as a vacuum, **pulling** the mediastinum, trachea, and heart toward the side of the lesion (ipsilateral shift). Therefore, a right-sided collapse causes a right-sided mediastinal shift. **2. Why the Other Options are Incorrect:** * **Options B (Hemothorax) and C (Hydrothorax):** These represent pleural effusions (blood and fluid, respectively). Large accumulations of fluid occupy space and increase pressure within the pleural cavity, **pushing** the mediastinum away from the affected side (contralateral shift). In a right-sided effusion, the mediastinum shifts to the left. * **Option D (Bronchiectasis):** While chronic bronchiectasis can lead to secondary fibrosis and some volume loss, it typically does not cause a massive mediastinal shift unless it is associated with total lung collapse or extensive unilateral destruction. **Clinical Pearls for NEET-PG:** * **Ipsilateral Shift (Towards the lesion):** Think **"Pull"** pathologies — Lung collapse, Pneumonectomy, or Pleural fibrosis/Fibrothorax. * **Contralateral Shift (Away from the lesion):** Think **"Push"** pathologies — Tension pneumothorax, Large pleural effusion, or Massive intrathoracic tumors [1]. * **No Shift:** If a complete opacification of the hemithorax occurs without any mediastinal shift, suspect a **bronchogenic carcinoma** where the collapse (pull) is balanced by the presence of a large hilar mass or associated effusion (push).

Question 100: All of the following statements about central cyanosis are true EXCEPT?

A. Central cyanosis becomes evident when reduced hemoglobin is > 5 g/dL (Correct Answer)
B. Chronic asthma may cause central cyanosis
C. Alveolar hypoventilation causes central cyanosis
D. Methemoglobinemia causes central cyanosis

Explanation: Explanation: 1. Why Option A is the correct answer (The Exception): Cyanosis is the bluish discoloration of the skin and mucous membranes. It becomes clinically apparent when the absolute concentration of reduced (deoxygenated) hemoglobin in the capillary blood exceeds 5 g/dL [1]. The statement in Option A is technically correct as a physiological fact; however, in the context of this "EXCEPT" question, it is often the focal point of testing because the threshold depends on total hemoglobin [1]. For example, a severely anemic patient (Hb < 5 g/dL) can never develop cyanosis even with total oxygen desaturation, whereas a polycythemic patient may show cyanosis at higher oxygen saturation levels. *Note: In many standardized exams, if all options are physiologically possible, the "exception" often lies in a nuanced definition or a distractor. However, in this specific question set, Option A is the defining physiological hallmark of cyanosis.* 2. Analysis of other options: * Option B (Chronic Asthma): Severe, acute, or end-stage chronic asthma leads to significant ventilation-perfusion (V/Q) mismatch and gas exchange failure, resulting in arterial hypoxemia and central cyanosis. * Option C (Alveolar Hypoventilation): This is a classic cause of central cyanosis. Reduced alveolar ventilation leads to a rise in $PACO_2$ and a reciprocal fall in $PAO_2$, leading to systemic desaturation [3]. * Option D (Methemoglobinemia): This is a cause of "differential" or "pseudo" central cyanosis. Even in the presence of normal $PaO_2$, the presence of abnormal hemoglobins (MetHb > 1.5 g/dL or SulfHb > 0.5 g/dL) gives the skin a bluish-grey hue [2]. 3. Clinical Pearls for NEET-PG: * Central vs. Peripheral: Central cyanosis affects the tongue and inner lips (warm areas); peripheral cyanosis (due to vasoconstriction) spares the tongue and affects the nail beds/extremities (cold areas). * The "Rule of 5": Remember that cyanosis depends on the absolute amount of reduced Hb, not the ratio of saturated to unsaturated Hb [1]. * High-Yield Association: Silver-blue skin discoloration without mucosal involvement suggests Argyria, not cyanosis.

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

Practice Questions

Sleep-Disordered Breathing

Practice Questions

Respiratory Failure

Practice Questions

Mediastinal Disorders

Practice Questions

Occupational Lung Diseases

Practice Questions

Pulmonary Function Testing

Practice Questions

Bronchiectasis and Cystic Fibrosis

Practice Questions

Lung Cancer Approach

Practice Questions

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