Pulmonology — MCQs

Pulmonology Indian Medical PG Practice Questions and MCQs

Question 701: Increased serum amylase in pleural effusion is seen in which of the following conditions?

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

Explanation: **Explanation:** Pleural fluid amylase levels are considered elevated when they exceed 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 effusion. It is typically seen in **Adenocarcinoma of the lung** or ovary. In these cases, the amylase is usually of the **salivary isoenzyme** type, produced by the tumor cells themselves rather than the pancreas [1]. **Analysis of Incorrect Options:** * **A. Rheumatoid Arthritis:** Characterized by very low glucose levels (<30 mg/dL), high LDH, and low pH. Amylase is not typically elevated. * **B. Tuberculosis:** Pleural fluid in TB is characterized by high protein (exudate), high adenosine deaminase (ADA) levels, and lymphocytic predominance, but not elevated amylase. * **C. Pulmonary Embolism:** Usually results in a non-specific exudate or transudate; amylase levels remain normal. **High-Yield Clinical Pearls for NEET-PG:** The differential diagnosis for **Amylase-Rich Pleural Effusion** (mnemonic: **ACID**) includes: 1. **A**cute Pancreatitis [2] (highest levels; pancreatic isoenzyme). 2. **C**arcinoma (Malignancy - salivary isoenzyme). 3. **I**atrogenic/Esophageal Rupture (Boerhaave syndrome; salivary isoenzyme from swallowed saliva). 4. **D**ramatic (Ectopic) Pregnancy rupture. * **Key Distinction:** If the question specifies **salivary amylase**, think Malignancy or Esophageal rupture [1]. If it specifies **pancreatic amylase**, think Pancreatitis [2] or Pancreatic pseudocyst.

Question 702: Pulmonary embolism is most commonly caused by which of the following?

A. Deep vein thrombosis of the leg (Correct Answer)
B. Increase in pulmonary vascular resistance
C. Fracture of the pelvic region
D. Congestive heart failure

Explanation: **Explanation:** **1. Why Option A is Correct:** Pulmonary Embolism (PE) is almost always a secondary complication of venous thromboembolism (VTE) [1]. Approximately **90-95% of all pulmonary emboli** originate from thrombi in the **deep veins of the lower extremities** (Deep Vein Thrombosis). Specifically, thrombi originating above the knee (proximal DVT)—involving the popliteal, femoral, or iliac veins—are the most likely to embolize to the pulmonary arterial tree [1]. **2. Why Other Options are Incorrect:** * **Option B (Increase in pulmonary vascular resistance):** This is a **consequence** of a pulmonary embolism, not a cause. When an embolus obstructs the pulmonary artery, it leads to increased resistance, which can result in acute right heart failure (Cor Pulmonale). * **Option C (Fracture of the pelvic region):** While pelvic fractures are a significant risk factor for DVT (due to immobilization and vessel injury) [1], they are a *predisposing factor* rather than the most common direct source. However, pelvic vein thrombi are the second most common source after leg veins. * **Option D (Congestive heart failure):** CHF is a clinical risk factor (Virchow’s triad: stasis) that increases the likelihood of developing a DVT, but it is not the source of the embolus itself [1]. **3. NEET-PG High-Yield Pearls:** * **Most common source:** Proximal deep veins of the leg (Popliteal and above) [1]. * **Most common symptom:** Sudden onset dyspnea [1]. * **Most common sign:** Tachypnea. * **Gold Standard Investigation:** CT Pulmonary Angiography (CTPA) [2]. * **ECG Finding:** Most common is Sinus Tachycardia; most specific is the **S1Q3T3 pattern** (indicates right heart strain). * **Virchow’s Triad:** Endothelial injury, Stasis, and Hypercoagulability are the three factors leading to VTE.

Question 703: All the following are radiological features of chronic cor pulmonale except?

A. Kerley B lines
B. Prominent lower lobe vessels (Correct Answer)
C. Pleural effusion
D. Cardiomegaly

Explanation: Explanation: Cor pulmonale refers to right ventricular (RV) hypertrophy and failure resulting from chronic pulmonary hypertension caused by primary lung disease. The radiological features reflect the underlying lung pathology and the subsequent strain on the right heart [1]. Why "Prominent lower lobe vessels" is the correct answer: In chronic cor pulmonale (and pulmonary hypertension), there is **pruning** of peripheral vessels. The hallmark is the enlargement of central pulmonary arteries with **tapering or narrowing of peripheral (distal) vessels**. Furthermore, in many underlying lung diseases like COPD, the lower lobe vessels may actually appear smaller or attenuated due to hyperinflation or destruction of the capillary bed. Prominent lower lobe vessels (cephalization) are more characteristic of left-sided heart failure (pulmonary venous congestion), not isolated right heart failure. Analysis of other options: * **Kerley B lines:** These represent thickened interlobular septa. While classic in left heart failure, they can be seen in chronic cor pulmonale if there is significant lymphatic obstruction or associated interstitial lung disease (like asbestosis) causing the cor pulmonale. * **Pleural effusion:** This is a recognized feature of right-sided heart failure due to increased systemic venous pressure and impaired lymphatic drainage [1]. * **Cardiomegaly:** Specifically, RV enlargement is a core feature [1]. On a PA chest X-ray, this manifests as an uplifted cardiac apex and filling of the retrosternal space on a lateral view. NEET-PG High-Yield Pearls: * **Most common cause of Cor Pulmonale:** COPD. * **ECG findings:** Right axis deviation, P-pulmonale (tall peaked P waves in lead II), and R/S ratio >1 in V1 [1]. * **Gold Standard Diagnosis:** Right heart catheterization (showing mean PAP >20 mmHg at rest). * **Westermark Sign:** A focal area of oligemia (lucent area) on CXR, indicating pulmonary embolism, which can cause *acute* cor pulmonale.

Question 704: Which of the following statements is/are true about obstructive lung disease?

A. mMRC dyspnea scale, grade 2 includes shortness of breath when hurrying up inclines.
B. Decreased FEV1/FVC; TLC is increased. (Correct Answer)
C. Normal PEFR and decreased in Lung volume.
D. Roflumilast is introduced in the management of COPD in Group C.

Explanation: ### Explanation **1. Why Option B is Correct:** Obstructive lung diseases (COPD, Asthma, Bronchiectasis) are characterized by an **increased resistance to airflow** due to partial or complete airway obstruction. * **FEV1/FVC Ratio:** This is the hallmark of obstruction [1]. Because the patient cannot exhale air rapidly, the FEV1 (Forced Expiratory Volume in 1 second) decreases significantly more than the FVC (Forced Vital Capacity), leading to a ratio **< 0.70** [1]. * **TLC (Total Lung Capacity):** Due to "air trapping" and hyperinflation (especially in emphysema) [2], the residual volume increases, leading to an **increased TLC**. **2. Why Other Options are Incorrect:** * **Option A:** This describes **mMRC Grade 1**. Grade 2 is defined as walking slower than people of the same age on level ground due to breathlessness or having to stop for breath when walking at own pace [3]. * **Option C:** In obstructive disease, **PEFR (Peak Expiratory Flow Rate) is decreased**, not normal. Decreased lung volumes are characteristic of *Restrictive* lung diseases (e.g., ILD). * **Option D:** According to GOLD guidelines, **Roflumilast** (a PDE-4 inhibitor) is typically considered for patients in **Group E** (formerly Group D) who have an FEV1 < 50% [4] and chronic bronchitis with frequent exacerbations despite dual or triple therapy. **3. High-Yield Clinical Pearls for NEET-PG:** * **Reversibility:** A post-bronchodilator increase in FEV1 of **>12% and >200 mL** suggests Asthma rather than COPD [1]. * **Flow-Volume Loop:** Obstructive disease shows a **"scooped-out"** appearance during the expiratory phase [1]. * **DLCO:** Differentiates types of obstruction; it is **decreased in Emphysema** (due to alveolar destruction) but usually **normal or increased in Asthma**. * **GOLD 2023/24 Update:** Groups C and D have been merged into **Group E** (Exacerbators) [4].

Question 705: Abnormal function of the epithelial chloride channel protein is the cause of which condition?

A. Ehlers Danlos syndrome
B. Marfan syndrome
C. Cystic fibrosis (Correct Answer)
D. Diabetes insipidus

Explanation: **Explanation:** The correct answer is **Cystic Fibrosis (CF)**. **Pathophysiology:** Cystic fibrosis is an autosomal recessive disorder caused by a mutation in the **CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene** located on chromosome 7. The CFTR protein functions as a cAMP-regulated **chloride channel** on the apical surface of epithelial cells [1]. * In the lungs and pancreas, defective chloride transport leads to decreased secretion of chloride and water, resulting in abnormally **thick, dehydrated mucus** [1]. This causes airway obstruction, recurrent infections (e.g., *Pseudomonas*), and pancreatic insufficiency. * In sweat glands, it prevents the reabsorption of chloride, leading to the classic clinical finding of "salty sweat." **Analysis of Incorrect Options:** * **A. Ehlers-Danlos Syndrome:** A group of genetic disorders affecting **collagen synthesis** (e.g., Type V or Type III collagen), leading to joint hypermobility and skin hyperextensibility. * **B. Marfan Syndrome:** An autosomal dominant connective tissue disorder caused by mutations in the **Fibrillin-1 gene** on chromosome 15, affecting the elastic fibers. * **C. Diabetes Insipidus:** Involves either a deficiency of ADH (Central) or resistance to ADH in the kidney tubules (Nephrogenic), primarily affecting **aquaporin-2 channels** or V2 receptors, not chloride channels. **High-Yield Clinical Pearls for NEET-PG:** * **Most common mutation:** ΔF508 (deletion of phenylalanine at position 508). * **Diagnosis:** Sweat Chloride Test (Gold Standard) — Chloride levels **>60 mmol/L** are diagnostic. * **Infertility:** 95% of males are infertile due to **Congenital Bilateral Absence of the Vas Deferens (CBAVD)** [1]. * **Newborn Screening:** Measurement of Immunoreactive Trypsinogen (IRT).

Question 706: Kerley B lines are seen at which location?

A. Apex
B. Cardiophrenic angle
C. Lung fissure
D. Pleural surface (Correct Answer)

Explanation: **Explanation:** **Kerley B lines** are short (1–2 cm), thin, horizontal lines seen on a chest X-ray that represent thickened **interlobular septa**. These lines are most commonly caused by pulmonary edema (fluid accumulation) or lymphatic obstruction. [1] 1. **Why the Pleural Surface is correct:** Kerley B lines are located in the periphery of the lungs. They are oriented perpendicular to the **pleural surface** and extend to reach it. They are most prominent at the lung bases because gravity causes fluid to accumulate in the dependent portions of the lung. 2. **Why other options are incorrect:** * **Apex:** Kerley **A** lines (longer, 2–6 cm) are typically found radiating from the hila toward the upper lobes (apex), not Kerley B lines. * **Cardiophrenic angle:** While Kerley B lines are seen in the lower zones, they are specifically peripheral/lateral rather than localized to the medial cardiophrenic angle. * **Lung fissure:** Fluid in the lung fissures appears as "pseudotumors" or thickening of the fissure itself, but Kerley B lines specifically represent the septa between lobules, not the major or minor fissures. **NEET-PG High-Yield Pearls:** * **Most common cause:** Congestive Heart Failure (CHF) with pulmonary venous hypertension (PCWP >18–20 mmHg). [1] * **Differential Diagnosis:** Mitral stenosis, Lymphangitic carcinomatosis, Asbestosis, and Sarcoidosis. * **Kerley A lines:** Longer, non-branching lines radiating from the hila (central). * **Kerley C lines:** Short, reticular lines found throughout the lungs (least commonly cited).

Question 707: In a normal healthy person, the arterial oxygen saturation (SpO2) is considered satisfactory if it is more than:

A. 80%
B. 85%
C. 90% (Correct Answer)
D. Any of the above

Explanation: The correct answer is **90%** because of the physiological relationship between partial pressure of oxygen ($PaO_2$) and hemoglobin saturation ($SaO_2$), as illustrated by the **Oxyhemoglobin Dissociation Curve** [1]. 1. **The Sigmoid Curve Concept:** The curve is S-shaped. Above an $SaO_2$ of 90%, the curve is relatively flat (the "plateau" phase). This means that even if the $PaO_2$ drops slightly, the hemoglobin remains highly saturated [1]. 2. **The "Critical Point":** An $SpO_2$ of **90%** corresponds roughly to a $PaO_2$ of **60 mmHg**. Below this point, the curve enters the "steep" phase. In this zone, even a tiny decrease in $PaO_2$ leads to a catastrophic drop in oxygen saturation, risking tissue hypoxia. Therefore, 90% is the clinical threshold for "satisfactory" oxygenation. **Why other options are incorrect:** * **80% and 85%:** These values fall on the steep portion of the dissociation curve. At 80% saturation, the $PaO_2$ is approximately 45–50 mmHg, indicating significant hypoxemia and impending respiratory failure. These levels are never considered satisfactory in a healthy individual. **High-Yield Clinical Pearls for NEET-PG:** * **P50 Value:** The $PaO_2$ at which hemoglobin is 50% saturated is normally **26.6 mmHg** [1]. * **Right Shift (Reduced Affinity):** Caused by increased $CO_2$, Acidosis ($H^+$), increased 2,3-BPG, and increased Temperature (Mnemonic: **CADET**, face Right!) [1]. * **Left Shift (Increased Affinity):** Caused by Alkalosis, Hypothermia, and Fetal Hemoglobin (HbF). * **Pulse Oximetry Limitation:** $SpO_2$ can be falsely normal in **Carbon Monoxide (CO) poisoning** because the oximeter cannot distinguish between oxyhemoglobin and carboxyhemoglobin.

Question 708: All of the following are true about Asthma, except?

A. Charcot-Leyden crystals may be seen in sputum.
B. Reversible airflow obstruction is a characteristic feature.
C. Large airways are involved.
D. Small airways are not involved. (Correct Answer)

Explanation: Asthma is a chronic inflammatory disorder of the airways characterized by hyperresponsiveness and reversible airflow obstruction [1]. **Why Option D is the correct answer (The Exception):** In asthma, the inflammatory process is not limited to the large bronchi; it involves the **entire tracheobronchial tree**, including the **small airways** (bronchioles <2mm in diameter) [1]. In chronic or severe asthma, "small airway disease" or "silent zone" involvement is a significant component of the pathology, leading to air trapping and remodeling. Therefore, stating that small airways are not involved is medically incorrect. **Analysis of Incorrect Options:** * **Option A:** Charcot-Leyden crystals are microscopic constituents of sputum in asthmatic patients. They are composed of **eosinophil-derived galectin-10** and signify eosinophilic inflammation. * **Option B:** The hallmark of asthma is **reversible** airflow obstruction (spontaneous or with bronchodilators) [1]. This distinguishes it from COPD, where obstruction is largely irreversible [2]. * **Option C:** Asthma definitely involves the large airways (bronchi), where smooth muscle hypertrophy and mucus hypersecretion are most prominent [1]. **NEET-PG High-Yield Pearls:** * **Curschmann Spirals:** Whorled mucus plugs found in sputum, representing cast-off epithelium from small airways. * **Creola Bodies:** Ciliated columnar epithelial cell clusters found in sputum. * **Diagnosis:** A >12% and >200 ml increase in FEV1 after inhalation of a short-acting beta-agonist (SABA) confirms reversibility [1]. * **Airway Remodeling:** Chronic inflammation leads to subepithelial fibrosis (thickening of the basement membrane), which is a classic histopathological finding.

Question 709: All of the following are recognized predisposing factors for adult respiratory distress syndrome, except?

A. Multiple blood transfusions
B. Septicemia
C. Status asthmaticus (Correct Answer)
D. Toxic gas inhalation

Explanation: **Explanation:** Acute Respiratory Distress Syndrome (ARDS) is characterized by diffuse alveolar-capillary damage leading to non-cardiogenic pulmonary edema [1]. The diagnosis requires the presence of bilateral opacities on imaging, a PaO2/FiO2 ratio < 300 mmHg, and the exclusion of cardiac failure [1]. **Why Status Asthmaticus is the Correct Answer:** While **Status Asthmaticus** is a severe medical emergency, it is primarily a disease of **airway obstruction** (bronchospasm and mucus plugging) rather than alveolar-capillary membrane damage. It does not typically lead to the diffuse inflammatory exudate or hyaline membrane formation characteristic of ARDS. Therefore, it is not a recognized predisposing factor. **Analysis of Incorrect Options (Predisposing Factors):** * **Septicemia (Option B):** This is the **most common** cause of ARDS. Systemic inflammation triggers the release of cytokines that damage the pulmonary endothelium [1]. * **Multiple Blood Transfusions (Option A):** This can lead to **TRALI** (Transfusion-Related Acute Lung Injury), a clinical form of ARDS caused by donor antibodies reacting against recipient leukocytes. * **Toxic Gas Inhalation (Option D):** Direct injury to the alveolar epithelium (e.g., chlorine gas, smoke, or high concentrations of oxygen) triggers an inflammatory cascade leading to ARDS. **NEET-PG High-Yield Pearls:** * **Most common cause of ARDS:** Sepsis (especially Gram-negative). * **Most common cause of ARDS in trauma:** Fat Embolism or Pulmonary Contusion. * **Pathological hallmark:** Diffuse Alveolar Damage (DAD) and Hyaline Membrane formation [1]. * **Berlin Criteria:** Timing (within 1 week), Imaging (bilateral opacities), Origin (not cardiac), and Oxygenation (PaO2/FiO2 < 300) [1]. * **Ventilatory Strategy:** Low tidal volume (6 mL/kg) "Lung Protective Ventilation" is the gold standard.

Question 710: Platypnea is seen with which of the following conditions?

A. Hepato-pulmonary syndrome (Correct Answer)
B. Hepato-renal syndrome
C. Renal artery stenosis
D. Kyphoscoliosis

Explanation: **Explanation:** **Platypnea** is a clinical sign characterized by shortness of breath (dyspnea) that is induced by sitting or standing and relieved by lying flat. It is frequently associated with **Orthodeoxia** (a decrease in arterial oxygen saturation when moving from a supine to an upright position) [3]. **1. Why Hepato-pulmonary Syndrome (HPS) is correct:** HPS is a triad of liver disease, increased alveolar-arterial oxygen gradient, and intrapulmonary vascular dilatations (IPVDs) [3]. These dilatations occur predominantly in the **lower lobes** of the lungs. When a patient stands up, gravity increases blood flow to these dilated basal vessels. This results in a significant **right-to-left shunt** (or ventilation-perfusion mismatch) because the blood bypasses the alveoli without being oxygenated, leading to acute dyspnea and desaturation [3]. **2. Why the other options are incorrect:** * **Hepato-renal syndrome:** This is functional renal failure in the setting of advanced liver disease. While it involves the liver, its primary manifestation is oliguria and rising creatinine, not positional dyspnea. * **Renal artery stenosis:** This typically presents with secondary hypertension (Renovascular hypertension) or "flash pulmonary edema," but not positional platypnea. * **Kyphoscoliosis:** This restrictive lung disease usually causes dyspnea that may worsen with exertion or lying down (orthopnea) due to chest wall mechanics, but it is not a classic cause of platypnea [2]. **Clinical Pearls for NEET-PG:** * **Classic Triad of HPS:** Liver cirrhosis + Hypoxemia + Intrapulmonary vascular dilatations [3]. * **Gold Standard Diagnosis:** Contrast-enhanced echocardiography (Bubble study). Appearance of microbubbles in the left atrium after 3–6 beats indicates intrapulmonary shunting. * **Other causes of Platypnea:** Atrial Septal Defect (ASD) or Patent Foramen Ovale (PFO) with a right-to-left shunt, and large pulmonary emboli. * **Contrast:** Orthopnea (difficulty breathing while lying flat) is most commonly seen in Left Heart Failure and COPD [1], [2].

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

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free