Pulmonology Practice Questions

Q: A 57-year-old male suffering from acute pancreatitis develops sudden onset breathlessness with a CVP < 18 mmHg. The chest X-ray shows bilateral infiltrates. What is the most likely diagnosis?

ARDS. ### Explanation The clinical presentation of sudden onset breathlessness, bilateral pulmonary infiltrates, and a predisposing factor (acute pancreatitis) strongly suggests **Acute Respiratory Distress Syndrome (ARDS)**. **Why ARDS is the Correct Answer:** ARDS is a form of non-cardiogenic pulmonary edema characterized by increased alveolar-capillary permeability [1]. According to the **Berlin Definition**, the diagnosis requires [1]: 1. **Acute onset** (within 1 week of a known clinical insult). 2. **Bilateral opacities** on chest imaging not fully explained by effusions or collapse [1]. 3. **Non-cardiogenic origin:** This is confirmed here by a **CVP < 18 mmHg** (or PCWP ≤ 18 mmHg), which rules out hydrostatic/left heart failure. Acute pancreatitis is a classic "indirect" cause of ARDS due to the systemic release of inflammatory mediators (cytokines and pancreatic enzymes) that damage the alveolar-capillary membrane [4]. **Why Other Options are Incorrect:** * **Congestive Left Heart Failure:** While it causes bilateral infiltrates, it is characterized by **elevated** filling pressures (CVP/PCWP > 18 mmHg) due to fluid backup [2]. * **Myocardial Infarction (MI):** While MI can lead to cardiogenic shock and pulmonary edema, the low CVP makes it an unlikely primary cause for the infiltrates in this scenario. * **Pulmonary Embolism:** Typically presents with a clear chest X-ray (or specific signs like Westermark sign) rather than diffuse bilateral infiltrates [3]. **High-Yield Clinical Pearls for NEET-PG:** * **PaO2/FiO2 Ratio in ARDS:** Mild (200–300), Moderate (100–200), Severe (< 100). * **Management Gold Standard:** Low tidal volume ventilation (6 mL/kg) to prevent volutrauma. * **Most common cause of ARDS:** Sepsis (Direct cause: Pneumonia). * **Radiology:** Characterized by "sparing of costophrenic angles" (unlike CHF).

Q: Superior vena cava (SVC) syndrome is most commonly associated with which of the following conditions?

Lung cancer. Superior Vena Cava (SVC) syndrome results from the physical obstruction of blood flow through the SVC, leading to facial edema, venous distention in the neck, and upper extremity swelling. **1. Why Lung Cancer is Correct:** Historically, infections like syphilis and tuberculosis were the leading causes. However, in modern clinical practice, **malignancy** accounts for approximately 60–90% of cases. Among these, **Lung Cancer** is the most common cause (approx. 75%), with **Small Cell Lung Cancer (SCLC)** being the most frequent histological subtype associated with SVC syndrome due to its central location and rapid growth. Non-Small Cell Lung Cancer (NSCLC), particularly squamous cell carcinoma, is also a significant contributor [1]. **2. Analysis of Incorrect Options:** * **Lymphoma (Option B):** This is the second most common malignant cause (approx. 10–15%), particularly Non-Hodgkin Lymphoma. While significant, it is statistically less frequent than lung cancer. * **Mediastinal Fibrosis (Option A):** This is a rare non-malignant cause, often associated with Histoplasmosis or idiopathic causes. * **Tuberculous Mediastinitis (Option D):** While a common cause of SVC syndrome in developing countries like India in the past, malignancy has now overtaken infectious etiologies in the overall clinical data. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause overall:** Lung Cancer (specifically Small Cell Lung Cancer) [1]. * **Most common non-malignant cause:** Iatrogenic (thrombosis due to indwelling central venous catheters or pacemakers). * **Pemberton’s Sign:** Facial flushing and respiratory distress upon raising both arms; a classic clinical sign of SVC obstruction (often seen in retrosternal goiters). * **Management:** For SCLC and Lymphoma, chemotherapy/radiotherapy is the mainstay. For NSCLC, stenting is often preferred for rapid palliation.

Q: Type II respiratory failure best relates to which of the following?

Alveolar hypoventilation. Respiratory failure is classified based on arterial blood gas (ABG) patterns [1]. **Type II Respiratory Failure** (Hypercapnic Respiratory Failure) is defined by a **PaCO₂ >45 mmHg**, usually accompanied by a PaO₂ <60 mmHg [3]. **Why Alveolar Hypoventilation is Correct:** The primary mechanism of Type II failure is **alveolar hypoventilation** [3]. Carbon dioxide (CO₂) levels in the blood are inversely proportional to alveolar ventilation. When the "pump" (respiratory muscles, chest wall, or CNS drive) fails to move enough air in and out of the lungs, CO₂ cannot be cleared, leading to hypercapnia [1]. Common causes include COPD, neuromuscular disorders (GBS, Myasthenia Gravis), and obesity hypoventilation syndrome [2]. **Analysis of Incorrect Options:** * **Alveolar Flooding (B) & Lung Atelectasis (D):** These conditions primarily cause **Type I Respiratory Failure** (Hypoxemic). They lead to a **V/Q mismatch or shunting**, where blood passes through non-ventilated alveoli [3]. While oxygenation drops significantly, CO₂ levels are usually low or normal because the patient hyperventilates to compensate [1]. * **Hypoperfusion of respiratory muscles (C):** While severe shock can lead to muscle fatigue and eventual failure, it is a secondary contributor rather than the defining pathophysiological mechanism of Type II failure. **High-Yield Clinical Pearls for NEET-PG:** * **Type I:** Hypoxemia with Normal/Low PaCO₂ (Mechanism: V/Q Mismatch) [3]. * **Type II:** Hypoxemia with **High PaCO₂** (Mechanism: Alveolar Hypoventilation) [3]. * **A-a Gradient:** In Type II failure due to extrapulmonary causes (e.g., drug overdose), the **A-a gradient is normal**. If the gradient is increased, it suggests intrinsic lung disease (e.g., COPD). * **Management:** The mainstay for Type II failure is improving ventilation, often via **Non-Invasive Ventilation (NIV/BiPAP)**.

Q: What is the most likely diagnosis?

Pulmonary artery hypertension. ***Pulmonary artery hypertension*** - Classic chest X-ray findings include **enlarged main pulmonary artery** and **right heart enlargement** with prominent right ventricle. - **Peripheral pruning** (oligemia) shows decreased vascular markings in outer lung fields due to elevated pulmonary pressures. *Interstitial lung disease* - Chest X-ray typically shows **reticular opacities** and **honeycombing** in lower zones, not the vascular changes seen here. - Associated with **progressive dyspnea** and **dry cough**, but lacks the cardiac enlargement pattern. *Congestive heart failure* - Presents with **cardiomegaly** and **pulmonary edema** showing **Kerley B lines** and **bat-wing** distribution. - **Bilateral pleural effusions** and **cephalization** of pulmonary vessels are common findings. *Bronchiectasis* - Characteristic **tram-track** and **ring shadows** representing dilated bronchi with thickened walls. - Associated with **recurrent infections** and **productive cough** with purulent sputum, not vascular prominence.

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

Malignancy. **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.

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

Decreased FEV1/FVC; TLC is increased.. ### 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 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 1

A 40-year-old man without a significant medical history presents with a 3-day history of fever, shaking chills, and a 15-minute episode of rigor. He also reports a cough productive of yellow-green sputum, anorexia, and right-sided pleuritic chest pain. Shortness of breath has been present for the past 12 hours. Chest x-ray reveals a consolidated right middle lobe infiltrate, and CBC shows an elevated neutrophil count with many band forms present. Which feature would most strongly support inpatient admission and IV antibiotic treatment for this patient?

Accepted Answer

Respiratory rate of 36/min

Answer

Recent exposure to a family member with influenza

Answer

Recent sexual exposure to an HIV-positive patient

Answer

Purulent sputum with gram-positive diplococci on Gram stain

Question 2

A 57-year-old male suffering from acute pancreatitis develops sudden onset breathlessness with a CVP < 18 mmHg. The chest X-ray shows bilateral infiltrates. What is the most likely diagnosis?

Accepted Answer

ARDS

Answer

Myocardial infarction

Answer

Congestive left heart failure

Answer

Pulmonary embolism

Question 3

Superior vena cava (SVC) syndrome is most commonly associated with which of the following conditions?

Accepted Answer

Lung cancer

Answer

Mediastinal fibrosis

Answer

Lymphoma

Answer

Tuberculous mediastinitis

Question 4

A 25-year-old male smoker presents with high-grade fever, chills, severe right-sided pleuritic chest pain, and cough with expectoration. Physical examination of the patient is likely to show which of the following?

Accepted Answer

Bronchial breath sounds

Answer

Increased percussion sounds

Answer

Decreased vocal fremitus

Answer

Decreased vocal resonance

Question 5

Type II Respiratory failure is characterized by?

Accepted Answer

Low PaO2 / High PaCO2

Answer

Low PaO2 / Low PaCO2

Answer

Normal PaCO2 / Low PaO2

Answer

High PaO2 / Low PaCO2

Question 6

Type II respiratory failure best relates to which of the following?

Accepted Answer

Alveolar hypoventilation

Answer

Alveolar flooding

Answer

Hypoperfusion of respiratory muscles

Answer

Lung atelectasis

Question 7

What is the most likely diagnosis?

Accepted Answer

Pulmonary artery hypertension

Answer

Interstitial lung disease

Answer

Congestive heart failure

Answer

Bronchiectasis

Question 8

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

Accepted Answer

Malignancy

Answer

Rheumatoid arthritis

Answer

Tuberculosis

Answer

Pulmonary embolism

Question 9

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

Accepted Answer

Prominent lower lobe vessels

Answer

Kerley B lines

Answer

Pleural effusion

Answer

Cardiomegaly

Question 10

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

Accepted Answer

Decreased FEV1/FVC; TLC is increased.

Answer

mMRC dyspnea scale, grade 2 includes shortness of breath when hurrying up inclines.

Answer

Normal PEFR and decreased in Lung volume.

Answer

Roflumilast is introduced in the management of COPD in Group C.

Pulmonology — MCQs

Pulmonology — MCQs

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