Pulmonology — MCQs

Pulmonology Indian Medical PG Practice Questions and MCQs

Question 841: Which is the best test to detect pulmonary embolism?

A. D dimer assay
B. MRI
C. Ventilation Perfusion scan
D. CT with IV contrast (Correct Answer)

Explanation: ***CT with IV contrast*** - **CT pulmonary angiography (CTPA)** is the **gold standard** for diagnosing pulmonary embolism due to its high sensitivity and specificity [1]. - It directly visualizes the **pulmonary arteries** and can detect emboli, making it the most definitive imaging test [1]. *D dimer assay* - A **negative D-dimer** can effectively **rule out PE** in low-to-intermediate probability patients, but a positive result is non-specific and requires further investigation. - It is a screening test with **poor specificity** in many clinical situations, such as surgery, trauma, cancer, or pregnancy, where D-dimer levels can be elevated for other reasons. *MRI* - **Magnetic resonance angiography (MRA)** can be used for PE diagnosis, particularly in patients unable to receive iodinated contrast or radiation. - However, it has **lower spatial resolution** and is generally less available and slower than CTPA, making it a second-line option. *Ventilation Perfusion scan* - A **V/Q scan** measures airflow (ventilation) and blood flow (perfusion) in the lungs to detect mismatches suggestive of PE [1]. - While useful, particularly in patients with **renal insufficiency** or **contrast allergy**, it often yields indeterminate results and is less sensitive than CTPA for definitive diagnosis [1].

Question 842: A lady presents with complaints of hemoptysis, and her chest X-ray appears to be normal. What is the next best investigation?

A. Bronchoscopy for airway evaluation
B. High-resolution CT scan of the chest (Correct Answer)
C. Sputum cytology for malignancy detection
D. Pulmonary function tests for lung assessment

Explanation: ***High-resolution CT scan of the chest*** - A **normal chest X-ray** does not rule out significant pulmonary pathology as it can miss small lesions, especially in cases of hemoptysis [1]. - An **HRCT scan** is more sensitive for detecting subtle parenchymal, airway, or vascular abnormalities that could be causing bleeding [1][2]. *Bronchoscopy for airway evaluation* - While bronchoscopy is a critical tool for investigating hemoptysis, performing an **HRCT first** helps localize the bleeding source or narrow down potential etiologies, guiding the bronchoscopist [1]. - Starting directly with bronchoscopy without prior imaging might miss **parenchymal lesions** not visible in the airways and increases procedural risk if the source is unknown. *Sputum cytology for malignancy detection* - **Sputum cytology** has a low sensitivity for detecting malignancy, especially if the lesion is not centrally located or actively shedding cells. - It is often reserved for patients with clear suspicion of cancer and usually follows imaging studies that indicate a suspicious mass [1]. *Pulmonary function tests for lung assessment* - **Pulmonary function tests** assess lung volumes, airflow, and gas exchange but do not diagnose the cause of hemoptysis. - These tests are primarily used for evaluating **respiratory mechanics** and the presence of obstructive or restrictive lung diseases, not acute bleeding.

Question 843: All of the following are direct causes of acute lung injury, except which of the following?

A. Aspiration
B. Lung contusion
C. Cardiopulmonary bypass with heart-lung machine (Correct Answer)
D. Toxic gas inhalation

Explanation: ***Cardiopulmonary bypass with heart-lung machine*** - While **cardiopulmonary bypass** can lead to acute lung injury (ALI)/ARDS in some patients, it is considered an **indirect cause**. [1] - The systemic inflammatory response triggered by bypass rather than direct lung insult typically mediates the injury. [1] *Aspiration* - **Aspiration of gastric contents** is a classic **direct cause** of acute lung injury. [1] - The acidic and particulate matter directly irritates and damages the alveolar epithelial and endothelial cells. *Toxic gas inhalation* - Inhaling **toxic gases** directly causes injury to the airway and alveolar lining. [2] - This direct damage can lead to inflammation and compromise gas exchange, precipitatingALI. [2] *Lung contusion* - **Lung contusion** is a **direct traumatic injury** to the lung tissue. - This physical damage causes hemorrhage and edema within the alveolar spaces, directly impairing lung function.

Question 844: Which of the following auscultatory findings, heard over the lung fields, does the term "Rhonchi" refer to?

A. Coarse, "bubbling" sounds
B. Fine, crackling sounds heard in late inspiration
C. Wheezing sounds during both inspiration and expiration (Correct Answer)
D. All of the options

Explanation: ***Wheezing sounds during both inspiration and expiration*** - **Rhonchi** are continuous, low-pitched, coarse, snoring-like sounds that are often heard during both inspiration and expiration [1]. - They are typically caused by **airflow obstruction** due to secretions, mucus, or foreign bodies in the larger airways. *Coarse, "bubbling" sounds* - **Coarse crackles** (also known as coarse rales) are often described as bubbling or gurgling sounds. - These sounds are generally associated with conditions like **pulmonary edema** [1] or chronic bronchitis, where there is fluid in the smaller airways. *Fine, crackling sounds heard in late inspiration* - These describe **fine crackles** (or fine rales), which are brief, discontinuous, high-pitched sounds. - They are typically heard in conditions like **interstitial lung disease** [2] or early congestive heart failure, indicating the sudden opening of collapsed or fluid-filled alveoli. *All of the options* - Each listed sound (coarse bubbling, fine crackling, and wheezing) represents a distinct auscultatory finding with different underlying physiological causes. - **Rhonchi** specifically refers to the wheezing or snoring-like sounds, distinguishing it from crackles.

Question 845: Which one of the following is not a feature of Kartagener syndrome?

A. Ciliary dyskinesia
B. situs inversus
C. Bronchiectasis
D. Pancreatic insufficiency (Correct Answer)

Explanation: ***Pancreatic insufficiency*** - **Pancreatic insufficiency** is a characteristic feature of **cystic fibrosis**, not Kartagener syndrome [1]. - Kartagener syndrome does not directly affect the exocrine function of the pancreas. *Bronchiectasis* - **Bronchiectasis** is a common feature of Kartagener syndrome due to impaired ciliary clearance leading to recurrent respiratory infections and subsequent airway damage [2]. - It results from the chronic inflammation and infection that dilates the bronchi. *Ciliary dyskinesia* - **Ciliary dyskinesia** is the *underlying defect* in Kartagener syndrome, involving abnormal structure or function of cilia [3]. - This leads to ineffective mucociliary clearance in the respiratory tract and immotile sperm. *Situs inversus* - **Situs inversus** (the complete transposition of major organs) is a hallmark of Kartagener syndrome, affecting about half of individuals with primary ciliary dyskinesia. - It occurs due to the impaired nodal ciliary beating during embryonic development, which is crucial for establishing normal visceral laterality.

Question 846: Which of the following ECG changes is least likely in a patient with left pneumothorax?

A. Electrical alternans
B. Left axis deviation (Correct Answer)
C. Small R wave
D. Inversion of T wave

Explanation: ***Left axis deviation*** - A **left pneumothorax** typically causes a **rightward shift** of the heart's electrical axis due to the collapse of the left lung pushing the mediastinum. - Therefore, **left axis deviation** is an unlikely finding; **right axis deviation** or a **shift towards the right** is more probable. *Inversion of T wave* - **T-wave inversions** can occur in the setting of pneumothorax due to changes in **cardiac position** and altered repolarization, often seen in combination with other low voltage signs [1]. - This is a non-specific but potential finding reflecting myocardial strain or positional changes. *Small R wave* - A **left pneumothorax** increases the distance between the heart and the chest wall, especially on the left side, leading to **attenuation of electrical signals** reaching the electrodes. - This commonly results in **decreased QRS voltage** and **small R waves**, particularly in the precordial leads. *Electrical alternans* - **Electrical alternans** (beat-to-beat variation in QRS amplitude or axis) is often associated with **pericardial effusion** or **cardiac tamponade**, indicating a swinging heart within the fluid. - While not a classic sign of pneumothorax, severe pneumothorax can cause significant mediastinal shift and cardiac compromise that *might* rarely mimic conditions leading to electrical alternans, though it is more typically associated with pericardial issues [1].

Question 847: Paradoxical breathing is seen in:

A. Diaphragmatic palsy (Correct Answer)
B. Severe left ventricular failure
C. COPD
D. Metabolic acidosis

Explanation: Paradoxical breathing is seen in: ***Diaphragmatic palsy*** - In **diaphragmatic palsy**, the weakened or paralyzed diaphragm is drawn *upwards* during inspiration due to negative intrathoracic pressure, leading to **paradoxical inward movement of the abdomen**. [3] - This abnormal movement is a key indicator of **diaphragmatic dysfunction** and results in inefficient breathing. *Severe left ventricular failure* - Patients with severe left ventricular failure often experience **orthopnea** and **paroxysmal nocturnal dyspnea** [2], and may have Cheyne-Stokes respiration, but not typically paradoxical breathing. - Their breathing pattern is characterized by rapid, shallow breaths due to **pulmonary congestion** and decreased lung compliance. *COPD* - Patients with COPD often exhibit the use of **accessory respiratory muscles** and a **barrel-chest** appearance due to air trapping. [1] - While they may have altered breathing patterns, classic paradoxical breathing is not a hallmark feature; rather, they experience **dyspnea** and **wheezing**. *Metabolic acidosis* - Metabolic acidosis leads to **Kussmaul breathing**, which is characterized by deep, labored breathing often associated with a normal or reduced respiratory rate. - This pattern is a compensatory mechanism to blow off CO2 and is distinct from paradoxical breathing.

Question 848: A 25-year-old male presents with recurrent respiratory infections, dextrocardia, and situs inversus totalis. What is the most likely diagnosis?

A. IgA deficiency
B. Aspiration pneumonia
C. Cystic fibrosis
D. Kartagener syndrome (Correct Answer)

Explanation: Detailed Analysis: ***Kartagener syndrome*** - This syndrome is a subgroup of **primary ciliary dyskinesia** characterized by the triad of **situs inversus totalis**, **chronic sinusitis**, and **bronchiectasis** [1]. - **Dextrocardia** and situs inversus in combination with recurrent respiratory infections strongly point towards impaired ciliary function [1]. *IgA deficiency* - This condition is associated with **recurrent respiratory infections** but does not cause structural abnormalities like **dextrocardia** or **situs inversus totalis**. - Patients typically present with increased susceptibility to **bacterial infections**, especially in the respiratory and gastrointestinal tracts. *Aspiration pneumonia* - While it can cause recurrent respiratory infections due to aspiration, it does not explain the presence of **congenital anomalies** such as **dextrocardia** and **situs inversus totalis**. - It results from the inhalation of foreign material into the lungs, often presenting with acute symptoms. *Cystic fibrosis* - This genetic disorder primarily affects **exocrine glands**, leading to thick, viscous mucus that obstructs airways and other ducts [2]. It causes recurrent lung infections and pancreatic insufficiency. - While it causes **recurrent respiratory infections** and can be associated with some congenital anomalies, it typically does not present with **dextrocardia** or **situs inversus totalis** [2].

Question 849: What is the most common symptom of interstitial lung disease?

A. Hemoptysis
B. Dyspnea (Correct Answer)
C. Wheezing
D. Substernal discomfort

Explanation: ***Dyspnea*** - **Dyspnea** (shortness of breath) is the hallmark symptom of interstitial lung disease (ILD), as the progressive fibrosis impairs gas exchange and lung compliance [1]. - It typically starts as **exertional dyspnea** and worsens over time, eventually becoming present even at rest [1], [2]. *Hemoptysis* - While hemoptysis can occur in some lung conditions, it is **not a common or primary symptom** of most forms of interstitial lung disease. - It might point towards other diagnoses like **lung cancer**, **bronchiectasis**, or **tuberculosis**. *Substernal discomfort* - **Substernal discomfort** can be associated with various conditions, including cardiac issues or gastroesophageal reflux disease, but it is **not a classic symptom** of ILD. - Chest pain or discomfort in ILD is usually **pleuritic** if present. *Wheezing* - **Wheezing** is indicative of **airway obstruction** (e.g., asthma, COPD) and is generally **not a feature of interstitial lung disease**. - ILD primarily affects the **parenchymal tissue** rather than the airways, so patients usually do not present with wheezing [1].

Question 850: In an emphysematous patient with bullous lesions, which is the best investigation to measure lung volumes?

A. Body plethysmography (Correct Answer)
B. Helium dilution
C. Trans diaphragmatic pressure
D. DLCO

Explanation: ***Body plethysmography*** - This method measures **total lung capacity (TLC)** by applying **Boyle's Law** and is not significantly affected by **trapped air** in bullae. - It directly measures changes in volume and pressure within a sealed chamber, providing accurate lung volumes even in the presence of **non-communicating air spaces**. *Helium dilution* - The **helium dilution technique** underestimates lung volumes in conditions with **trapped air** or poorly communicating air spaces, such as **bullae**, because helium cannot diffuse into these areas. - This method relies on the equilibration of a known amount of helium throughout the lungs, which is unreliable when significant parts of the lung are not ventilated. *Trans diaphragmatic pressure* - **Transdiaphragmatic pressure (Pdi)** is primarily used to assess **diaphragmatic strength and function**, not for measuring static lung volumes. - It involves measuring the pressure difference between the gastric and esophageal balloons and is unrelated to **total lung capacity** or **residual volume**. *DLCO* - **Diffusing capacity of the lung for carbon monoxide (DLCO)** measures the efficiency of gas transfer from the alveoli to the red blood cells, not lung volumes. - While it is a valuable test in emphysema (typically reduced), it does not provide information about the **absolute volumes of the lung**.

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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