Respiratory Diseases Practice Questions

Q: Which of the following are features of cystic fibrosis?

Lung normal at birth. **Explanation:** **Cystic Fibrosis (CF)** is a multisystem genetic disorder caused by a mutation in the **CFTR gene**. 1. **Why Option A is Correct:** In patients with CF, the **lungs are histologically and functionally normal at birth**. The respiratory pathology is not congenital but acquired. It begins shortly after birth due to defective chloride transport, leading to dehydrated, viscid endobronchial secretions. This results in a cycle of airway obstruction, chronic inflammation, and recurrent infections (typically by *S. aureus* and *P. aeruginosa*), eventually leading to bronchiectasis. 2. **Why Other Options are Incorrect:** * **Option B (Abnormal sweat chloride):** While this is a hallmark feature of CF (Chloride >60 mEq/L), the question asks for "features," and in the context of standard NEET-PG patterns, Option A is the specific developmental fact often tested. (Note: If this were a multiple-choice question where B is also true, A remains the classic "pathological" starting point). * **Option C & D:** CF follows an **Autosomal Recessive** inheritance pattern (not dominant). The defect is located on the long arm of **Chromosome 7** (not Chromosome 11). The most common mutation is **ΔF508**. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest Manifestation:** Meconium ileus (seen in 15-20% of newborns). * **Gold Standard Diagnosis:** Sweat Chloride test (Pilocarpine Iontophoresis). * **Infertility:** 95% of males are infertile due to **Congenital Bilateral Absence of Vas Deferens (CBAVD)**; females have decreased fertility due to thick cervical mucus. * **Pancreas:** Exocrine insufficiency leads to malabsorption and steatorrhea. * **Vitamin Deficiencies:** Deficiency of fat-soluble vitamins (A, D, E, K) is common.

Q: Which one of the following values is not a feature of acute severe asthma?

PEF of 60 to 70% of expected. **Explanation:** The classification of asthma severity is a high-yield topic for NEET-PG. To identify the correct answer, one must distinguish between **Moderate** and **Acute Severe Asthma** (Status Asthmaticus). **1. Why Option B is the correct answer:** In **Acute Severe Asthma**, the Peak Expiratory Flow (PEF) is significantly reduced, typically **less than 50%** of the predicted or best value. A PEF of 60–70% is characteristic of a **Moderate Exacerbation**. Therefore, this value is "not a feature" of the severe category. **2. Analysis of Incorrect Options (Features of Severe Asthma):** * **Heart rate > 110/min (Option A):** Tachycardia is a physiological response to respiratory distress, hypoxia, and increased work of breathing. In children, the threshold varies by age, but >110 bpm is a standard marker for severity in adults and older children. * **Pulsus Paradoxus (Option C):** This refers to an exaggerated fall in systolic BP (>10 mmHg) during inspiration. In severe asthma, massive negative intrathoracic pressure is required to breathe, which impacts cardiac filling and output. Its presence signifies significant airway obstruction. * **PaO2 < 8 kPa (Option D):** 8 kPa is approximately **60 mmHg**. Hypoxemia (PaO2 < 60 mmHg) without cyanosis is a hallmark of severe asthma. If the PaO2 drops further or PaCO2 begins to rise (normalizing or increasing), it indicates impending respiratory failure. **Clinical Pearls for NEET-PG:** * **Silent Chest:** The most ominous sign in asthma; it indicates such little air movement that wheezing disappears. * **Normal PaCO2:** In an acute attack, a patient should be hyperventilating (low PaCO2). A "normal" PaCO2 (40 mmHg) in a struggling asthmatic is a sign of muscle fatigue and **impending respiratory failure**. * **Life-threatening features:** PEF < 33%, SpO2 < 92%, silent chest, cyanosis, exhaustion, or hypotension.

Q: In a child with a suspected foreign body in the lung, what is the next best step in management?

Rigid bronchoscopy. **Explanation:** The definitive management for a suspected tracheobronchial foreign body (FB) in a child is **Rigid Bronchoscopy**. In pediatric practice, this is considered the "gold standard" because it serves both a diagnostic and therapeutic purpose. Unlike flexible scopes, the rigid bronchoscope provides a stable airway, allows for superior visualization, and has a wider lumen to accommodate various grasping forceps for FB removal. **Analysis of Options:** * **Chest X-ray (Option B):** While often the first investigation performed, a normal X-ray does not rule out a foreign body (most are radiolucent). If clinical suspicion is high (e.g., sudden onset choking, unilateral wheeze), the patient must proceed to bronchoscopy regardless of imaging results. * **Flexible Endoscopy (Option C):** While useful for visualizing the distal airways, it is generally avoided for FB removal in children because it cannot protect the airway as effectively as a rigid scope and lacks the mechanical strength to extract sharp or bulky objects. * **Direct Laryngoscopy (Option D):** This is only useful if the foreign body is lodged in the supraglottic area or larynx. It does not allow for the evaluation of the tracheobronchial tree. **NEET-PG High-Yield Pearls:** * **Most common site:** Right main bronchus (due to it being wider, shorter, and more vertical). * **Most common age:** 1–3 years. * **Classic Triad:** Sudden onset coughing/choking, wheezing, and diminished breath sounds. * **X-ray findings:** Obstructive emphysema (most common), atelectasis, or a mediastinal shift away from the affected side. * **Gold Standard:** Rigid bronchoscopy under general anesthesia.

Q: A young boy developed respiratory distress. On examination, the chest X-ray showed hyperinflation of one lung. Which of the following is the most possible diagnosis?

Foreign body aspiration. ### Explanation The correct answer is **Foreign body aspiration (FBA)**. **Why it is correct:** In pediatric patients, foreign body aspiration often acts as a **"ball-valve" mechanism**. During inspiration, the airways dilate, allowing air to pass the obstruction. However, during expiration, the airways narrow, causing the foreign body to completely occlude the lumen. This results in air-trapping and subsequent **obstructive hyperinflation** of the affected lung. While Congenital Lobar Emphysema (CLE) also causes hyperinflation, FBA is statistically the most common cause of sudden-onset respiratory distress with unilateral hyperinflation in a previously healthy child. **Why the other options are incorrect:** * **Congenital Lobar Emphysema (CLE):** While it presents with hyperinflation, it is typically diagnosed in the **neonatal period or early infancy** (usually <6 months) due to cartilage deficiency. The question implies a "young boy," suggesting an older age group where FBA is more prevalent. * **Atelectasis:** This involves the collapse of lung tissue, which would show **opacity and volume loss** (mediastinal shift toward the lesion) on X-ray, rather than hyperinflation. * **Bronchiectasis:** This is a chronic condition characterized by permanent dilation of bronchi. X-ray findings typically show "tram-track" opacities or cystic changes, not acute unilateral hyperinflation. **Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis/Management:** Rigid Bronchoscopy (for both diagnosis and removal). * **Classic Triad:** Sudden onset of coughing, wheezing, and diminished breath sounds (though only present in ~50% of cases). * **Radiology:** If the X-ray is inconclusive, perform **expiratory films** or lateral decubitus films; the affected lung will fail to collapse.

Q: Which of the following childhood disorders is associated with an omega-shaped epiglottis?

Laryngomalacia. **Explanation:** **Laryngomalacia** is the most common congenital anomaly of the larynx and the leading cause of congenital stridor in infants. It is characterized by an abnormal softening of the supraglottic structures, which collapse inward during inspiration. The classic endoscopic finding is an **"omega-shaped" (Ω) epiglottis**, caused by the lateral folds of the epiglottis curling inward. This is often accompanied by short aryepiglottic folds and redundant arytenoid mucosa. **Analysis of Incorrect Options:** * **Epiglottitis:** This is an acute bacterial infection (typically *H. influenzae* type B) characterized by a "cherry-red," swollen epiglottis. On a lateral neck X-ray, it presents with the **"Thumb sign,"** not an omega shape. * **Subglottic Stenosis:** This involves narrowing of the airway below the vocal cords. It is characterized by the **"Steeple sign"** (subglottic narrowing) on an AP X-ray and is often associated with prolonged intubation. * **Choanal Atresia:** This is a congenital blockage of the posterior nasal passage. It presents with cyclical cyanosis (relieved by crying) and is diagnosed by the inability to pass a catheter through the nose. **Clinical Pearls for NEET-PG:** * **Clinical Presentation:** Inspiratory stridor that worsens when the infant is supine, crying, or feeding, and improves when prone. * **Diagnosis:** Flexible fiberoptic laryngoscopy is the gold standard (shows collapse of supraglottic tissues). * **Management:** Most cases are self-limiting and resolve by 18–24 months. Severe cases (causing failure to thrive or cor pulmonale) require **supraglottoplasty**.

Question 1

A child presents with fever, stridor, and barking cough. An X-ray is provided below. Which of the following is true about the patient?

Accepted Answer

Symptoms are predominantly caused by involvement of the subglottis.

Answer

Antibiotics should be started immediately.

Answer

The X-ray is showing the thumb sign.

Answer

The condition is caused by H. influenzae b.

Question 2

Which of the following is FALSE regarding cystic fibrosis?

Accepted Answer

It is associated with chromosome 7.

Answer

It is associated with the CFTR gene.

Answer

It follows autosomal recessive inheritance.

Answer

It is characterized by recurrent respiratory tract infections.

Question 3

Which of the following are features of cystic fibrosis?

Accepted Answer

Lung normal at birth

Answer

Abnormal sweat chloride tests

Answer

Autosomal dominant

Answer

Defect in Chromosome 11

Question 4

Which one of the following values is not a feature of acute severe asthma?

Accepted Answer

PEF of 60 to 70% of expected

Answer

Heart rate more than 110/min

Answer

Pulsus paradoxus

Answer

PaO2 of less than 8 kPa

Question 5

Which of the following findings are true about bronchiolitis in children?

Accepted Answer

Caused by respiratory syncytial virus, hyperinflation of the chest, and may lead to bronchial asthma later in life

Answer

Hyperinflation of the chest, pleural effusion, and may lead to bronchial asthma later in life

Answer

Caused by respiratory syncytial virus and hyperinflation of the chest

Question 6

In a child with a suspected foreign body in the lung, what is the next best step in management?

Accepted Answer

Rigid bronchoscopy

Answer

Chest x-ray

Answer

Flexible endoscopy

Answer

Direct laryngoscopy

Question 7

A young boy developed respiratory distress. On examination, the chest X-ray showed hyperinflation of one lung. Which of the following is the most possible diagnosis?

Accepted Answer

Foreign body aspiration

Answer

Congenital lobar emphysema

Answer

Bronchiectasis

Answer

Atelectasis

Question 8

A 3-week-old male infant, born to a primiparous mother, presents with noisy breathing. The child is afebrile, sleeping and feeding well, and has a normal clinical examination. What is the recommended management protocol?

Accepted Answer

Reassure and give saline nasal drops

Answer

Begin IV antibiotics

Answer

Give racemic epinephrine

Answer

Order a chest X-ray

Question 9

Which of the following childhood disorders is associated with an omega-shaped epiglottis?

Accepted Answer

Laryngomalacia

Answer

Epiglottitis

Answer

Subglottic stenosis

Answer

Choanal atresia

Question 10

What is the most common contributory factor to respiratory failure in patients with cystic fibrosis?

Accepted Answer

Pseudomonas infection

Answer

Haemophilus influenzae infection

Answer

Associated heart failure

Answer

Hypokalemia

Respiratory Diseases — MCQs

Respiratory Diseases — MCQs

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