Pulmonology — MCQs

Pulmonology Indian Medical PG Practice Questions and MCQs

Question 791: Which sinus is most commonly affected in sinusitis?

A. Frontal sinus
B. Ethmoid sinus
C. Maxillary sinus (Correct Answer)
D. Sphenoid sinus

Explanation: ***Maxillary sinus*** - The **maxillary sinus** is the largest of the paranasal sinuses and is involved in nearly all cases of acute rhinosinusitis. - Its **ostium** is located superiorly, which makes **drainage against gravity** difficult, predisposing it to infection and inflammation. *Frontal sinus* - The **frontal sinuses** are frequently affected, but less commonly than the maxillary sinus. - They develop later than other sinuses, making them less common in younger children. *Ethmoid sinus* - The **ethmoid sinuses** are involved in many cases of sinusitis, especially in children, as they are present at birth. - However, they are not the most common sinus to be singularly affected in acute sinusitis. *Sphenoid sinus* - The **sphenoid sinus** is the least commonly affected paranasal sinus in sinusitis [1]. - Involvement of the sphenoid sinus often indicates a more severe or chronic infection.

Question 792: A patient with known sarcoidosis presents with dyspnea and a dry cough. A chest X-ray shows bilateral hilar lymphadenopathy. What is the most appropriate next step in management?

A. Bronchoscopy with biopsy
B. Serum ACE levels
C. High-resolution CT scan of the chest (Correct Answer)
D. Immediate initiation of glucocorticoids

Explanation: A high-resolution CT (HRCT) scan provides more detailed imaging of the lungs and lymph nodes, which is crucial for assessing the extent and severity of pulmonary involvement in sarcoidosis [1]. It helps differentiate between various patterns of lung involvement (e.g., ground-glass opacities, nodules, fibrosis) and guides further management, including the need for biopsy or treatment [1]. While a biopsy is definitive for diagnosing sarcoidosis, it is usually reserved for cases where the diagnosis is uncertain or when there is atypical presentation or progression [2]. Given the patient's known sarcoidosis and classic chest X-ray findings [2], a less invasive step to assess disease extent is preferred before considering biopsy.

Question 793: Which ECG pattern is observed in pulmonary embolism?

A. S1Q3T3 (Correct Answer)
B. S3Q3T1
C. S1Q1T3
D. S3Q3T3

Explanation: ***S1Q3T3*** - The **S1Q3T3 pattern** on an ECG is a classic, though not always present, sign of **acute cor pulmonale** due to a large pulmonary embolism [1]. - It describes a **prominent S wave in lead I**, a **Q wave in lead III**, and an **inverted T wave in lead III** [1]. *S3Q3T1* - This pattern is not typically associated with pulmonary embolism. The combination of an S wave in lead III, Q wave in lead III, and T wave in lead I does not point to the characteristic right heart strain. - ECG changes in PE primarily reflect acute right ventricular strain and dilatation, which manifest differently [1]. *S1Q1T3* - This pattern is not a recognized ECG finding for pulmonary embolism. A Q wave in lead I is generally not characteristic of PE. - The classic PE pattern involves specific changes in leads I and III reflecting the acute right heart overload [1]. *S3Q3T3* - While a Q wave and inverted T wave in lead III are part of the classic PE pattern (S1Q3T3), an S wave in lead III alone is not diagnostic for the classic pattern, which requires an S wave in lead I. - The S1 component in lead I is crucial for the full classic S1Q3T3 pattern, indicating right ventricular strain.

Question 794: In a patient with obstructive lung disease, which parameter is typically reduced during spirometry testing?

A. Forced expiratory volume in 1 second (FEV1) (Correct Answer)
B. Residual volume (RV)
C. Forced vital capacity (FVC)
D. Total lung capacity (TLC)

Explanation: ***Forced expiratory volume in 1 second (FEV1)*** - In **obstructive lung diseases**, there is significant airflow limitation, meaning the patient struggles to exhale air quickly [1]. - This leads to a characteristic **reduction in FEV1**, as less air can be forcefully exhaled within the first second [1]. *Residual volume (RV)* - **Residual volume** is typically increased in obstructive lung diseases due to **air trapping**, as patients cannot fully empty their lungs. - An increase in RV reflects the inability to exhale all the air, not a reduction in expiratory flow. *Forced vital capacity (FVC)* - While **FVC** can be normal or slightly reduced in obstructive lung disease, it is its **ratio to FEV1 (FEV1/FVC)** that is consistently low and diagnostic [1]. - An isolated reduction in FVC is more characteristic of **restrictive lung diseases**, where lung volumes are primarily affected. *Total lung capacity (TLC)* - **Total lung capacity** is often normal or even increased in obstructive lung diseases due to **hyperinflation** and air trapping. - An increase in TLC is a compensatory mechanism and does not directly indicate airflow obstruction.

Question 795: Inspiratory stridor is typically associated with which type of airway lesion?

A. Supraglottic lesions (Correct Answer)
B. Subglottic lesions
C. Tracheal lesions
D. Bronchial lesions

Explanation: ***Supraglottic lesions*** - **Inspiratory stridor** occurs due to turbulent airflow during inspiration, which is characteristic of **supraglottic obstruction** as the negative pressure during inspiration causes collapse of the lax tissues above the vocal cords [1]. - Common causes include **laryngomalacia**, epiglottitis, and foreign body aspiration in the pharynx or larynx above the vocal cords [1]. *Subglottic lesions* - **Subglottic lesions** typically cause **biphasic stridor** or expiratory stridor, as obstruction below the vocal cords affects both inspiratory and expiratory airflow. - Examples include **subglottic stenosis** or croup, where turbulent airflow occurs in both phases of respiration. *Tracheal lesions* - **Tracheal lesions** often lead to **biphasic inspiratory and expiratory stridor**, as the trachea is a rigid structure and obstruction affects airflow in both directions [1]. - Conditions like **tracheal stenosis** or tumors in the trachea cause constant airway narrowing [1]. *Bronchial lesions* - **Bronchial lesions** are more likely to cause **expiratory wheezing** or stridor, particularly if they are distal to the trachea. - Obstruction in the bronchi leads to air trapping and restricted outflow during expiration, producing a high-pitched whistling sound.

Question 796: In which of the following conditions is oxygen therapy generally not considered useful?

A. Acute asthma exacerbation
B. Bacterial pneumonia
C. Severe laryngeal obstruction (Correct Answer)
D. Pulmonary fibrosis

Explanation: Directly address the conditions where oxygen therapy is effective or ineffective. ***Severe laryngeal obstruction*** - In cases of **severe laryngeal obstruction**, the primary issue is a mechanical blockage preventing air from reaching the lungs, not impaired gas exchange at the alveolar level [3]. Oxygen therapy alone cannot bypass this physical obstruction. - The immediate and critical intervention for severe laryngeal obstruction is to secure an airway, often through procedures like **intubation** or **tracheostomy**, rather than relying on supplemental oxygen [4]. *Acute asthma exacerbation* - Patients with acute asthma exacerbations often experience **bronchoconstriction** and **airway inflammation**, leading to ventilation-perfusion mismatch and hypoxemia [2]. - Oxygen therapy is crucial in these patients to correct hypoxemia and reduce the work of breathing, improving tissue oxygenation [1]. *Bacterial pneumonia* - **Bacterial pneumonia** causes consolidation and inflammation in the lung parenchyma, impairing gas exchange and leading to hypoxemia [2]. - Oxygen therapy is a standard treatment to maintain adequate arterial oxygen saturation and support respiratory function in patients with pneumonia [1]. *Pulmonary fibrosis* - **Pulmonary fibrosis** involves scarring and thickening of the lung tissue, which impedes the diffusion of oxygen across the alveolar-capillary membrane. - Supplemental oxygen helps overcome this diffusion defect, particularly during exertion, improving hypoxemia and reducing dyspnea [1].

Question 797: A patient presents with symptoms of wheezing, shortness of breath, and a history of asthma. Which of the following conditions does this most likely signify?

A. Normal lung function
B. Obstructive lung disease (Correct Answer)
C. Restrictive lung disease
D. Both

Explanation: ***Obstructive lung disease*** - **Wheezing** and **shortness of breath** in a patient with a **history of asthma** are classic signs of airway narrowing, which is characteristic of obstructive lung diseases [1]. - **Asthma** is a prototypical **obstructive lung disease** where inflammation and bronchoconstriction impede airflow, especially during exhalation [2]. *Normal lung function* - This option is incorrect because the patient is experiencing **symptoms** like wheezing and shortness of breath, which indicate **impaired respiratory function**. - **Normal lung function** would involve unobstructed airflow and the absence of such respiratory distress. *Restrictive lung disease* - **Restrictive lung diseases** typically involve reduced lung volumes due to stiffness of the lungs or chest wall, leading to difficulty **inhaling**. - While shortness of breath can be present, **wheezing** is not a primary symptom and the patient's history of asthma strongly points away from a restrictive process [1]. *Both* - The combination of **wheezing** and a history of **asthma** specifically points to an **obstructive process** rather than a blend of both, as asthma's pathology is rooted in airway obstruction [1]. - While some complex lung conditions can have elements of both, the prominent features described here are characteristic of **obstructive lung disease**.

Question 798: Type IV respiratory failure occurs due to

A. Alveolar flooding
B. Inability to eliminate CO2
C. Hypoperfusion of respiratory muscles (Correct Answer)
D. Lung atelectasis

Explanation: Type IV respiratory failure occurs due to ***Hypoperfusion of respiratory muscles*** - Type IV respiratory failure is specifically defined as **shock-induced respiratory failure** due to inadequate oxygen delivery to the respiratory muscles. - This leads to **respiratory muscle fatigue** and an inability to maintain adequate ventilation, causing both hypoxemia and hypercapnia. *Alveolar flooding* - This condition is characteristic of **Type I respiratory failure** [1], which is primarily hypoxemic and involves impaired oxygenation [2]. - Causes include **pulmonary edema** (cardiogenic or non-cardiogenic ARDS) where fluid fills the alveoli [3]. *Inability to eliminate CO2* - This describes **Type II respiratory failure**, also known as **hypercapnic respiratory failure**, due to inadequate alveolar ventilation [2]. - It results from conditions like **COPD exacerbation**, neuromuscular disorders, or severe airway obstruction, where the primary issue is CO2 retention [1]. *Lung atelectasis* - Leads to **Type I (hypoxemic) respiratory failure** by causing an intrapulmonary shunt, where unventilated parts of the lung are still perfused [2]. - It is the collapse of lung tissue, typically due to **airway obstruction** or compression, but does not directly cause Type IV failure.

Question 799: FEV1/FVC is decreased in:

A. Kyphosis and scoliosis
B. Restrictive lung disease
C. Pulmonary fibrosis
D. Obstructive lung disease such as asthma (Correct Answer)

Explanation: ***Obstructive lung disease such as asthma*** - In **obstructive lung diseases**, there is difficulty with **airflow out of the lungs**, leading to a disproportionate decrease in **FEV1** compared to FVC [1]. - This results in a **reduced FEV1/FVC ratio**, which is a hallmark of conditions like asthma and COPD [1]. *Kyphosis and scoliosis* - These are **restrictive lung conditions** due to chest wall deformities, which typically show a reduced FVC but a **normal or increased FEV1/FVC ratio**. - The primary problem is reduced lung volume, not airflow obstruction. *Restrictive lung disease* - In general, **restrictive lung diseases** are characterized by **reduced lung volumes** (decreased FVC) but **preserved or even increased airflow rates**. - Therefore, the **FEV1/FVC ratio** is usually **normal or elevated**, not decreased. *Pulmonary fibrosis* - **Pulmonary fibrosis** is a type of **restrictive lung disease** where lung tissue becomes stiff and scarred, leading to decreased lung volumes. - While FVC is decreased, the **FEV1/FVC ratio typically remains normal or even increases** because both FEV1 and FVC decrease proportionally, or FEV1 decreases less.

Question 800: Lights criteria is used for

A. Diagnosing pleural effusions (Correct Answer)
B. Diagnosing pericardial effusions
C. Diagnosing ascites
D. Diagnosing increased intracranial tension

Explanation: ***Diagnosing pleural effusions*** - **Light's criteria** is a set of guidelines used to differentiate between an exudative and a transudative **pleural effusion** [1]. - It involves comparing the levels of protein and lactate dehydrogenase (LDH) in pleural fluid to those in serum [1]. *Diagnosing pericardial effusions* - **Pericardial effusions** are typically evaluated using echocardiography and clinical assessment, not Light's criteria. - The focus for pericardial effusions is often on their size, hemodynamic impact, and underlying cause, rather than protein/LDH ratios. *Diagnosing ascites* - **Ascites**, the accumulation of fluid in the peritoneal cavity, is evaluated using the **serum-ascites albumin gradient (SAAG)** to differentiate causes, not Light's criteria. - **Light's criteria** are specific to pleural fluid analysis [1]. *Diagnosing increased intracranial tension* - **Increased intracranial tension (ICT)** is diagnosed by clinical signs, imaging (CT/MRI), and direct intracranial pressure monitoring. - This condition involves brain physiology and is unrelated to effusions or fluid analysis parameters used in Light's criteria.

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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