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Egyptian Board Thoracic Diseases study materials
Egyptian Board Thoracic Diseases study resources

Egyptian Board Thoracic Diseases practice questions

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Question 1Respiratory Physiology and Pathophysiology

At the end of a quiet expiration, which pressure relationship exists between the alveoli and the mouth in a healthy seated adult?

  1. Alveolar pressure is markedly higher than atmospheric pressure because elastic recoil persists
  2. Alveolar pressure equals pleural pressure because the airways are fully collapsed
  3. Alveolar pressure is lower than atmospheric pressure because the chest wall pulls outward
  4. Alveolar pressure is equal to atmospheric pressure because airflow has ceased Correct answer.

Explanation

At end-expiration airflow stops, so no pressure gradient exists between alveoli and the mouth; alveolar pressure therefore equals atmospheric pressure. Intrapleural pressure remains negative but does not equal alveolar pressure. Elastic recoil is balanced by outward chest wall recoil at functional residual capacity.

Question 2Respiratory Physiology and Pathophysiology

A 30-year-old man has a tidal volume of 500 mL and a respiratory rate of 12 breaths per minute. His anatomic dead space is estimated at 150 mL. What is his alveolar ventilation?

  1. 1800 mL/min
  2. 3600 mL/min
  3. 4200 mL/min Correct answer.
  4. 6000 mL/min

Explanation

Alveolar ventilation equals (tidal volume minus dead space) multiplied by respiratory rate, so (500 − 150) × 12 = 4200 mL/min. Minute ventilation alone would be 6000 mL/min, which overstates gas exchange. Dead space ventilation accounts for the 1800 mL/min difference.

Question 3Respiratory Physiology and Pathophysiology

Which change in lung mechanics is the direct consequence of surfactant deficiency in the alveoli?

  1. Increased airway resistance caused by bronchial smooth muscle hypertrophy
  2. Increased surface tension with a tendency to alveolar collapse at low lung volumes Correct answer.
  3. Reduced lung compliance caused by increased elastic recoil of the chest wall
  4. Reduced surface tension with alveolar hyperinflation and air trapping

Explanation

Surfactant lowers alveolar surface tension and stabilizes alveoli of differing sizes according to the Laplace relationship. Deficiency raises surface tension, promotes alveolar collapse at low volumes, and reduces compliance. The problem lies in the air-liquid interface, not in airway smooth muscle or chest wall elasticity.

Question 4Respiratory Physiology and Pathophysiology

A patient with severe chronic obstructive pulmonary disease has a flattened diaphragm on chest radiography. Which functional consequence is most consistent with this finding?

  1. Increased elastic recoil of the lung because of hyperinflation
  2. Reduced inspiratory pressure generation because the diaphragm is mechanically disadvantaged Correct answer.
  3. Increased inspiratory muscle efficiency because the diaphragm operates at a shorter length
  4. Reduced total lung capacity because of air trapping

Explanation

Hyperinflation flattens the diaphragm and shortens its sarcomeres, placing it at a mechanical disadvantage in the length-tension relationship. The result is reduced capacity to generate inspiratory pressure. Hyperinflation also increases, not reduces, residual volume and total lung capacity.

Question 5Respiratory Physiology and Pathophysiology

Which statement correctly describes the regional distribution of ventilation in an upright healthy lung?

  1. Ventilation is greatest at the base because airway resistance is highest at the apex
  2. Ventilation is greatest at the apex because alveolar compliance is highest there
  3. Ventilation is uniform from apex to base because intrapleural pressure is equal throughout
  4. Ventilation is greatest at the base because alveoli there start from a smaller volume on the compliance curve Correct answer.

Explanation

In the upright lung, gravity makes intrapleural pressure more negative at the apex, so apical alveoli are already partly inflated and operate on the flatter part of the compliance curve. Basal alveoli begin at lower volumes and have greater slope, so they receive more ventilation per unit volume. This is a compliance effect, not a difference in airway resistance.

Question 6Respiratory Physiology and Pathophysiology

In a healthy upright adult, which region of the lung has the highest ventilation-perfusion ratio?

  1. All zones are equal because blood flow is uniform
  2. The mid-zone at the level of the hilum
  3. The lung base
  4. The lung apex Correct answer.

Explanation

Both ventilation and perfusion increase from apex to base, but perfusion increases far more steeply because of gravity. The apex therefore receives relatively more ventilation than perfusion and has the highest ventilation-perfusion ratio, while the base has the lowest. The mid-zone lies between these extremes.

Question 7Respiratory Physiology and Pathophysiology

A patient with a large pulmonary embolism has a region of lung that is ventilated but not perfused. What is the effect on that region's ventilation-perfusion ratio and on physiologic dead space?

  1. The ratio falls and shunt fraction increases
  2. The ratio falls to zero and dead space decreases
  3. The ratio rises toward infinity and dead space increases Correct answer.
  4. The ratio remains unchanged because ventilation adjusts immediately

Explanation

When perfusion ceases but ventilation continues, the ventilation-perfusion ratio approaches infinity because the denominator is zero. Such units behave as dead space, so physiologic dead space rises and gas exchange in that region is wasted. A ratio of zero describes the opposite situation, a true shunt.

Question 8Respiratory Physiology and Pathophysiology

Which statement best explains why oxygen diffusion from alveoli to capillary blood is impaired more than carbon dioxide diffusion in a patient with severe diffuse interstitial lung disease?

  1. Oxygen is more soluble in plasma and therefore diffuses more slowly
  2. Oxygen has a lower diffusion coefficient than carbon dioxide and is more dependent on the diffusion gradient Correct answer.
  3. Carbon dioxide is actively secreted by the alveolar epithelium
  4. Carbon dioxide has a higher molecular weight and diffuses more rapidly

Explanation

Carbon dioxide diffuses about twenty times faster than oxygen through the alveolar membrane because of its much higher solubility. When the membrane thickens, oxygen transfer is therefore affected first, while carbon dioxide is usually cleared until disease is very advanced. This is why hypoxemia precedes hypercapnia in interstitial disease.

Question 9Respiratory Physiology and Pathophysiology

A patient's arterial blood gas shows pH 7.28, PaCO2 60 mmHg, and bicarbonate 27 mmol/L. Which acid-base disturbance is present?

  1. Acute respiratory acidosis Correct answer.
  2. Acute respiratory alkalosis
  3. Metabolic acidosis with respiratory compensation
  4. Chronic respiratory acidosis with full metabolic compensation

Explanation

The low pH with an elevated PaCO2 indicates a primary respiratory acidosis. The bicarbonate is only modestly raised, which is consistent with acute rather than chronic retention of carbon dioxide. Full renal compensation would take days and would raise bicarbonate further.

Question 10Respiratory Physiology and Pathophysiology

A patient with myasthenia gravis develops alveolar hypoventilation. Which arterial blood gas pattern is expected in the absence of coexisting lung disease?

  1. Hypoxemia with hypocapnia
  2. Hypoxemia with hypercapnia Correct answer.
  3. Hyperoxemia with respiratory alkalosis
  4. Normal oxygenation with hypercapnia only

Explanation

Alveolar hypoventilation raises alveolar and arterial carbon dioxide and simultaneously lowers alveolar oxygen according to the alveolar gas equation. The result is hypercapnia with hypoxemia. The hypoxemia of pure hypoventilation is corrected by increasing the inspired oxygen, unlike shunt.

Question 11Respiratory Physiology and Pathophysiology

A patient has hypoxemia that does not improve substantially when the fractional inspired oxygen is raised to 1.0. Which mechanism of hypoxemia is most likely?

  1. Low inspired oxygen partial pressure
  2. Diffusion limitation at rest
  3. Hypoventilation
  4. Intrapulmonary shunt Correct answer.

Explanation

Blood passing through true shunt does not contact ventilated alveoli, so supplemental oxygen cannot reach it and hypoxemia persists. In contrast, hypoventilation, low inspired oxygen, and diffusion limitation usually respond well to a higher inspired oxygen concentration.

Question 12Respiratory Physiology and Pathophysiology

Which statement about the oxyhemoglobin dissociation curve describes the Bohr effect?

  1. An increase in carbon dioxide and hydrogen ion concentration shifts the curve to the right and reduces oxygen affinity Correct answer.
  2. A fall in pH increases hemoglobin oxygen affinity
  3. A rise in temperature shifts the curve to the left and increases oxygen affinity
  4. An increase in 2,3-diphosphoglycerate shifts the curve to the left

Explanation

The Bohr effect describes the rightward shift of the oxyhemoglobin dissociation curve when carbon dioxide and hydrogen ions increase, as occurs in exercising tissue. This reduces hemoglobin oxygen affinity and enhances oxygen unloading where it is needed. A fall in pH has the same rightward effect.

Question 13Respiratory Physiology and Pathophysiology

A patient with chronic anemia has a normal arterial partial pressure of oxygen. Which parameter is most useful for assessing oxygen delivery to tissues?

  1. Arterial oxygen content combined with cardiac output Correct answer.
  2. Arterial oxygen saturation alone
  3. Alveolar-arterial oxygen gradient alone
  4. Arterial partial pressure of oxygen alone

Explanation

Oxygen delivery equals arterial oxygen content multiplied by cardiac output. Arterial oxygen content depends mainly on hemoglobin concentration and saturation, so in anemia the partial pressure and saturation can be normal while delivery is reduced. The alveolar-arterial gradient reflects gas exchange efficiency, not delivery.

Question 14Respiratory Physiology and Pathophysiology

During quiet breathing, which muscles are primarily responsible for inspiration?

  1. The transversus abdominis and external oblique muscles
  2. The diaphragm and external intercostal muscles Correct answer.
  3. The rectus abdominis and internal intercostal muscles
  4. The sternocleidomastoid and scalene muscles alone

Explanation

Quiet inspiration is produced mainly by contraction of the diaphragm, with assistance from the external intercostal muscles. These muscles increase thoracic volume and lower intrapleural pressure. The abdominal and internal intercostal muscles are primarily expiratory, while accessory neck muscles are recruited in distress.

Question 15Respiratory Physiology and Pathophysiology

A patient with a large left-sided pleural effusion is found to have reduced lung volumes on that side. Which mechanism best explains the reduction in ventilation of the affected lung?

  1. Compression atelectasis reduces regional compliance and increases the work of breathing Correct answer.
  2. Airway smooth muscle constriction reduces airway caliber directly
  3. Surfactant production increases and stiffens the alveoli
  4. Pulmonary capillary blood flow increases and reduces alveolar volume

Explanation

A large effusion compresses the underlying lung, producing compressive atelectasis with reduced regional compliance. More pressure is needed to inflate that region, so ventilation falls. The effect arises from mechanical compression rather than from airway smooth muscle or surfactant changes.

Question 16Respiratory Physiology and Pathophysiology

Which statement about closing volume and airway closure is correct?

  1. Small airways close first during expiration because they lack cartilaginous support Correct answer.
  2. Closing volume is independent of age and body position
  3. Closing volume is the volume of air remaining after maximal expiration
  4. Large airways close first because they have the highest compliance

Explanation

Small peripheral airways have little or no cartilage and depend on elastic recoil of surrounding lung tissue for patency. During expiration they close first, particularly at low lung volumes and in dependent regions. Closing volume increases with age and in the supine position.

Question 17Respiratory Physiology and Pathophysiology

A patient with acute severe asthma has an arterial blood gas showing pH 7.30, PaCO2 50 mmHg, and PaO2 60 mmHg. What does the rising carbon dioxide indicate?

  1. A metabolic alkalosis compensating for airway obstruction
  2. Impending respiratory failure with inadequate alveolar ventilation Correct answer.
  3. Normal gas exchange for a patient with asthma
  4. Mild asthma with effective hyperventilation

Explanation

In acute asthma, hyperventilation usually lowers carbon dioxide and produces hypocapnia. A normal or rising PaCO2 signals that the patient can no longer maintain the increased work of breathing, and impending respiratory failure should be considered. This is a warning sign rather than reassuring improvement.

Question 18Respiratory Physiology and Pathophysiology

Which factor most increases the work of breathing in a patient with severe airflow obstruction?

  1. Increased lung elastic recoil requiring greater inspiratory effort
  2. Reduced dead space requiring larger tidal volumes
  3. Increased chest wall compliance requiring greater muscle shortening
  4. Increased airway resistance requiring greater pressure to maintain flow Correct answer.

Explanation

In obstructive disease, airway resistance is elevated, so a larger pressure gradient is needed to achieve the same airflow, increasing resistive work. Emphysema also reduces elastic recoil, which tends to promote dynamic airway collapse and air trapping. Increased elastic recoil and reduced dead space are not features of obstruction.

Question 19Respiratory Physiology and Pathophysiology

What is the physiologic role of the Hering-Breuer inflation reflex in adult humans?

  1. It increases heart rate during inspiration
  2. It controls airway smooth muscle tone independently of breathing
  3. It initiates inspiration when the lungs are deflated
  4. It terminates inspiration when lung inflation reaches a threshold, limiting overinflation Correct answer.

Explanation

Stretch receptors in the airways sense lung inflation and, through vagal afferents, inhibit further inspiration. In adults this reflex is weak at normal tidal volumes but becomes important at large tidal volumes, protecting against overinflation. It does not initiate inspiration or regulate airway tone.

Question 20Respiratory Physiology and Pathophysiology

Which statement correctly describes the pulmonary circulation in response to alveolar hypoxia?

  1. Hypoxia increases bronchial artery flow and reduces pulmonary vascular resistance
  2. Hypoxia causes pulmonary vasodilatation that increases perfusion of poorly ventilated units
  3. Hypoxic pulmonary vasoconstriction diverts blood away from poorly ventilated alveoli Correct answer.
  4. Hypoxia has no effect on pulmonary vascular resistance in adults

Explanation

Alveolar hypoxia constricts the small pulmonary arteries supplying that region, a response unique to the pulmonary circulation. This hypoxic pulmonary vasoconstriction diverts blood toward better-ventilated areas and helps preserve the ventilation-perfusion ratio. Global hypoxia, however, raises pulmonary artery pressure.

Question 21Pulmonary Diagnostic Procedures and Imaging

A 24-year-old man has sudden right-sided chest pain and breathlessness. Chest radiograph shows a thin, visible visceral pleural line with no lung markings beyond it. Which finding on the radiograph most reliably confirms a pneumothorax rather than a skin fold?

  1. Increased radiolucency of the hemithorax
  2. Flattening of the ipsilateral hemidiaphragm
  3. Absence of bronchovascular markings peripheral to the pleural line Correct answer.
  4. Mediastinal shift toward the affected side

Explanation

A true pneumothorax is diagnosed by identifying the visceral pleural line with no lung markings extending beyond it to the chest wall. A skin fold can mimic a pleural line but lung markings continue beyond it, so the absence of peripheral markings is the discriminating feature. Other signs such as hyperlucency or diaphragmatic flattening are supportive but less specific.

Question 22Pulmonary Diagnostic Procedures and Imaging

Which radiographic projection is preferred for detecting a small amount of free pleural fluid that is not visible on a standard erect posteroanterior film?

  1. Lateral decubitus view with the affected side down Correct answer.
  2. Supine anteroposterior view
  3. Apical lordotic view
  4. Expiratory posteroanterior view

Explanation

Free pleural fluid layers out over the dependent hemithorax, so a lateral decubitus film with the affected side down allows as little as a few milliliters to be detected as a band of opacity. The erect PA film requires roughly 200 mL before blunting of the costophrenic angle appears. Supine and expiratory films do not improve sensitivity for small effusions.

Question 23Pulmonary Diagnostic Procedures and Imaging

On a chest radiograph, a homogeneous opacity with a meniscus that rises laterally in the costophrenic angle is most consistent with which finding?

  1. Pleural thickening
  2. Lobar consolidation
  3. Diaphragmatic hernia
  4. Pleural effusion Correct answer.

Explanation

The meniscus sign, in which the opacity is thicker laterally and tapers medially, reflects fluid tracking up the lateral chest wall and is characteristic of a free pleural effusion in an erect patient. Consolidation tends to be bounded by fissures without a meniscus. Pleural thickening is usually non-dependent and does not layer.

Question 24Pulmonary Diagnostic Procedures and Imaging

A patient with suspected pulmonary embolism has a normal chest radiograph. Which investigation is the most appropriate next step to confirm the diagnosis when renal function is normal?

  1. High-resolution CT of the chest
  2. CT pulmonary angiography Correct answer.
  3. Contrast echocardiography
  4. Ventilation-perfusion scintigraphy

Explanation

CT pulmonary angiography directly visualizes thrombus within the pulmonary arteries and is the first-line confirmatory test in hemodynamically stable patients with suspected pulmonary embolism. A normal chest radiograph does not exclude embolism. V/Q scanning is reserved for situations where contrast is contraindicated.

Question 25Pulmonary Diagnostic Procedures and Imaging

Which feature on CT most reliably distinguishes a benign from a malignant solitary pulmonary nodule?

  1. Smooth well-defined margins
  2. Location in the upper lobe
  3. A pattern of diffuse, central, or popcorn calcification Correct answer.
  4. A nodule diameter of 8 mm

Explanation

Diffuse, central, or popcorn-like calcification is characteristic of benign lesions such as granulomas or hamartomas and strongly favors a benign etiology. Size, margin characteristics, and lobar location influence malignancy probability but do not by themselves establish benignity.

Question 26Pulmonary Diagnostic Procedures and Imaging

A patient with a solitary pulmonary nodule is assessed using the Brock model. Which variable is included in this malignancy risk prediction model?

  1. Nodule size Correct answer.
  2. Serum carcinoembryonic antigen level
  3. Serum alpha-1 antitrypsin level
  4. History of tuberculosis

Explanation

The Brock model predicts malignancy risk for pulmonary nodules detected on CT and includes nodule size, nodule type (solid, part-solid, ground-glass), nodule count, spiculation, and upper-lobe location. Serum tumor markers and prior tuberculosis are not part of the model.

Question 27Pulmonary Diagnostic Procedures and Imaging

A patient with a suspected malignant pleural effusion undergoes thoracentesis. Which pleural fluid finding most strongly suggests an exudate by Light's criteria?

  1. Pleural fluid to serum protein ratio of 0.6 Correct answer.
  2. Pleural fluid lactate dehydrogenase below two-thirds of the upper normal serum limit
  3. Pleural fluid pH of 7.45
  4. Pleural fluid glucose of 90 mg/dL

Explanation

Light's criteria classify an effusion as exudative if the pleural fluid to serum protein ratio exceeds 0.5, the pleural fluid to serum LDH ratio exceeds 0.6, or pleural fluid LDH exceeds two-thirds of the upper normal serum limit. A protein ratio of 0.6 satisfies the protein criterion. The other values are not exudative criteria.

Question 28Pulmonary Diagnostic Procedures and Imaging

Which pleural fluid characteristic is most typical of a rheumatoid pleurisy?

  1. Chylomicron-rich milky fluid
  2. Very high glucose with a low protein
  3. Very low glucose with a high rheumatoid factor titer Correct answer.
  4. Predominantly eosinophilic cell count

Explanation

Rheumatoid pleural effusions characteristically show markedly low glucose (often below 30 mg/dL), high LDH, and elevated rheumatoid factor, reflecting intense pleural inflammation. This pattern helps distinguish rheumatoid effusion from other exudates.

Question 29Pulmonary Diagnostic Procedures and Imaging

A 60-year-old smoker has a central lung mass with ipsilateral mediastinal lymph node enlargement. Which procedure provides both tissue diagnosis and mediastinal nodal staging in a single session?

  1. Sputum cytology
  2. Endobronchial ultrasound-guided transbronchial needle aspiration Correct answer.
  3. Transthoracic fine-needle aspiration of a mediastinal node
  4. CT-guided percutaneous core biopsy of the lung mass

Explanation

Endobronchial ultrasound-guided transbronchial needle aspiration samples paratracheal and subcarinal nodes under real-time imaging, providing both cytologic diagnosis and mediastinal staging in one procedure. Percutaneous biopsy of the lung mass does not stage the mediastinum.

Question 30Pulmonary Diagnostic Procedures and Imaging

Which finding on chest radiograph is the classic sign of a large left-sided pneumothorax causing mediastinal shift away from the affected side?

  1. Silhouette sign
  2. Tension shift of the mediastinum to the contralateral side with depressed hemidiaphragm Correct answer.
  3. Deep sulcus sign
  4. Air bronchogram

Explanation

A tension pneumothorax produces contralateral mediastinal shift, depression of the ipsilateral hemidiaphragm, and a large radiolucent hemithorax with absent lung markings. This is a clinical emergency requiring immediate decompression rather than imaging-dependent management.

Question 31Pulmonary Diagnostic Procedures and Imaging

A patient with suspected interstitial lung disease has a chest radiograph showing bilateral reticular opacities. Which imaging modality is most appropriate to characterize the pattern and guide diagnosis?

  1. Ventilation-perfusion scintigraphy
  2. High-resolution CT of the chest Correct answer.
  3. Conventional CT without high-resolution technique
  4. Ultrasound of the chest

Explanation

High-resolution CT with thin sections and a high-spatial-frequency reconstruction algorithm is the standard for evaluating suspected interstitial lung disease, allowing characterization of reticulation, honeycombing, and ground-glass opacity. It guides diagnosis and often obviates surgical lung biopsy.

Question 32Pulmonary Diagnostic Procedures and Imaging

On high-resolution CT, which pattern is most characteristic of usual interstitial pneumonia?

  1. Centrilobular nodules with tree-in-bud opacities
  2. Subpleural, basal-predominant honeycombing with traction bronchiectasis Correct answer.
  3. Diffuse ground-glass opacity with sparing of the subpleural region
  4. Upper-lobe cavitary lesions

Explanation

The usual interstitial pneumonia pattern is defined by subpleural and basal-predominant reticulation, honeycombing, and traction bronchiectasis with minimal ground-glass opacity. This pattern, in the appropriate clinical context, supports a diagnosis of idiopathic pulmonary fibrosis.

Question 33Pulmonary Diagnostic Procedures and Imaging

Which feature on CT best distinguishes a lung abscess from an empyema?

  1. An acute angle with the chest wall and a thick enhancing wall Correct answer.
  2. Presence of an air-fluid level
  3. A split-pleura sign
  4. A smooth inner margin and an obtuse angle with the chest wall

Explanation

A lung abscess typically forms an acute angle with the chest wall and has a thick, irregular wall, whereas an empyema forms an obtuse angle and often shows the split-pleura sign with smooth inner margins. Both may contain air-fluid levels, so that feature does not discriminate.

Question 34Pulmonary Diagnostic Procedures and Imaging

A patient with a suspected malignant pleural effusion undergoes medical thoracoscopy. Which finding is most consistent with malignant pleural disease?

  1. Diffuse uniform pleural erythema
  2. Smooth pleural surface with no biopsy abnormality
  3. Nodular pleural thickening with irregular vascularity Correct answer.
  4. Thin translucent adhesions

Explanation

Medical thoracoscopy allows direct visualization and biopsy of the pleura; nodular thickening with irregular vascularity is characteristic of malignancy and permits targeted biopsy. Smooth surfaces and simple adhesions are more typical of benign inflammatory disease.

Question 35Pulmonary Diagnostic Procedures and Imaging

Which test is the most appropriate initial investigation for a patient with suspected obstructive sleep apnea who is otherwise healthy?

  1. Chest radiograph
  2. Awake arterial blood gas analysis
  3. Spirometry with bronchodilator response
  4. Overnight polysomnography Correct answer.

Explanation

Overnight polysomnography is the reference standard for diagnosing obstructive sleep apnea, quantifying the apnea-hypopnea index and oxygen desaturation. Simplified home sleep testing may be used in selected patients, but full polysomnography remains the diagnostic standard.

Question 36Pulmonary Diagnostic Procedures and Imaging

A patient with a suspected tracheal obstruction has a flow-volume loop showing flattening of both inspiratory and expiratory limbs. What does this pattern suggest?

  1. Small airways disease
  2. Variable extrathoracic obstruction
  3. Variable intrathoracic obstruction
  4. Fixed upper airway obstruction Correct answer.

Explanation

Flattening of both the inspiratory and expiratory limbs of the flow-volume loop indicates a fixed upper airway obstruction, such as tracheal stenosis or a rigid tracheal lesion. Variable lesions produce flattening of only one limb depending on whether they are intra- or extrathoracic.

Question 37Pulmonary Diagnostic Procedures and Imaging

Which finding on bronchoalveolar lavage fluid is most suggestive of alveolar hemorrhage?

  1. Cloudy return that clears with sequential aliquots
  2. Predominance of eosinophils above 25 percent
  3. Presence of asbestos bodies
  4. Progressively bloodier return with increasing aliquots Correct answer.

Explanation

Sequential lavage aliquots that become progressively bloodier indicate ongoing bleeding into the alveolar space, supporting alveolar hemorrhage. A traumatic tap produces bloody return that clears with subsequent aliquots.

Question 38Pulmonary Diagnostic Procedures and Imaging

Which structure is most commonly sampled by transbronchial lung biopsy to diagnose sarcoidosis?

  1. Bronchial cartilage
  2. Peribronchovascular interstitium Correct answer.
  3. Alveolar spaces
  4. Pleura

Explanation

Sarcoidosis produces noncaseating granulomas distributed along the bronchovascular bundles and interlobular septa, so transbronchial biopsy targeting the peribronchovascular interstitium yields high diagnostic sensitivity. Sampling pleura or cartilage is not appropriate.

Question 39Pulmonary Diagnostic Procedures and Imaging

A patient with a peripheral lung nodule undergoes CT-guided percutaneous needle biopsy. Which complication is most common?

  1. Massive hemoptysis
  2. Pneumothorax Correct answer.
  3. Chest wall hematoma
  4. Systemic air embolism

Explanation

Pneumothorax is the most frequent complication of CT-guided percutaneous lung biopsy, occurring in a substantial minority of patients and requiring chest tube drainage in a smaller proportion. Hemoptysis and air embolism are less common but potentially serious.

Question 40Pulmonary Diagnostic Procedures and Imaging

Which finding on chest radiograph suggests left lower lobe collapse?

  1. Elevation of the right hemidiaphragm
  2. Loss of the left hemidiaphragm silhouette with a retrocardiac triangular opacity Correct answer.
  3. Tracheal shift toward the right
  4. Hyperlucency of the left upper zone

Explanation

Left lower lobe collapse produces a triangular opacity behind the heart that obscures the left hemidiaphragm, sometimes with a sail sign. The left heart border usually remains visible because the lingula is spared. Tracheal shift is typically minimal or absent with lower lobe collapse.

Question 41Pulmonary Diagnostic Procedures and Imaging

Which radiographic sign indicates a right upper lobe collapse?

  1. Air bronchogram in the left lower zone
  2. Golden S sign with a displaced minor fissure Correct answer.
  3. Silhouette sign of the left heart border
  4. Deep sulcus sign

Explanation

Right upper lobe collapse elevates the minor fissure and can produce a Golden S sign when a central mass causes convex bulging of the fissure with concave peripheral collapse. This sign suggests an obstructing central lesion.

Question 42Pulmonary Diagnostic Procedures and Imaging

A patient with suspected pulmonary tuberculosis has a chest radiograph showing upper-lobe cavitation. Which sputum examination is the most appropriate initial microbiological test?

  1. Cytology for malignant cells
  2. Acid-fast bacilli smear with culture on solid or liquid media Correct answer.
  3. Gram stain and routine bacterial culture
  4. Fungal culture

Explanation

Sputum acid-fast bacilli smear and mycobacterial culture remain the initial microbiological tests for suspected pulmonary tuberculosis, with molecular testing such as Xpert MTB/RIF increasingly used for rapid detection and resistance screening. Routine bacterial and fungal cultures do not detect mycobacteria.

Question 43Pulmonary Diagnostic Procedures and Imaging

A patient with a history of asbestos exposure has pleural plaques on CT. Which additional imaging feature most suggests progression to malignant mesothelioma?

  1. Diaphragmatic pleural calcification
  2. Bilateral pleural plaques without effusion
  3. Nodular pleural thickening with mediastinal pleural involvement Correct answer.
  4. Circumscribed calcified pleural plaques

Explanation

Malignant mesothelioma typically produces nodular pleural thickening that involves the mediastinal pleura and encases the lung, often with an associated effusion. Simple calcified plaques are markers of asbestos exposure but are not themselves malignant.

Question 44Pulmonary Diagnostic Procedures and Imaging

Which parameter measured during polysomnography defines an apnea?

  1. An arousal lasting 3 seconds
  2. Reduction of airflow by 30 percent for 5 seconds
  3. Oxygen desaturation of 3 percent
  4. Cessation of airflow for at least 10 seconds Correct answer.

Explanation

An apnea is defined as cessation of airflow for at least 10 seconds during sleep, classified as obstructive, central, or mixed according to respiratory effort. A hypopnea requires a partial reduction in airflow with desaturation or arousal rather than complete cessation.

Question 45Obstructive Airway Diseases (Asthma, COPD, Bronchiectasis)

A 24-year-old man with a history of childhood asthma presents with episodic wheeze and cough that occur mainly at night and after exercise. Spirometry shows an FEV1/FVC ratio of 0.78 with a 16% improvement in FEV1 after inhaling salbutamol. Which single finding best confirms the diagnosis of asthma?

  1. Presence of a prolonged expiratory phase on auscultation
  2. A history of atopy with positive skin-prick tests
  3. Reversibility of airflow obstruction after a short-acting bronchodilator Correct answer.
  4. A raised total serum IgE level

Explanation

The diagnosis of asthma is confirmed by demonstrating variable expiratory airflow limitation, most commonly significant bronchodilator reversibility on spirometry. Symptoms and atopy support the diagnosis but are not confirmatory because they occur in other conditions. Demonstrating reversibility establishes the physiological hallmark of asthma.

Question 46Obstructive Airway Diseases (Asthma, COPD, Bronchiectasis)

Which spirometric pattern is characteristic of persistent airflow limitation in a patient with COPD?

  1. Normal FEV1/FVC with a reduced diffusion capacity
  2. FEV1/FVC above 0.80 with reduced total lung capacity
  3. FEV1/FVC below 0.70 after bronchodilator administration Correct answer.
  4. Increased FEV1/FVC ratio with a normal residual volume

Explanation

COPD is defined by persistent airflow limitation, and the accepted spirometric criterion is a post-bronchodilator FEV1/FVC ratio below 0.70. This fixed ratio confirms obstruction that does not fully reverse. Other patterns describe restriction or isolated gas-transfer abnormalities.

Question 47Obstructive Airway Diseases (Asthma, COPD, Bronchiectasis)

A 62-year-old smoker with COPD reports chronic productive cough with large volumes of purulent sputum. Which pathological change most directly explains the sputum production?

  1. Thickening of the pulmonary capillary basement membrane
  2. Hyperplasia of submucosal glands and goblet cells in the large airways Correct answer.
  3. Fibrosis of the pleural membrane
  4. Destruction of alveolar walls distal to the terminal bronchiole

Explanation

Chronic bronchitis, the mucus-hypersecretion component of COPD, results from hypertrophy and hyperplasia of bronchial submucosal glands and increased goblet cells. These changes produce the chronic productive cough. Alveolar destruction underlies emphysema, not sputum production.

Question 48Obstructive Airway Diseases (Asthma, COPD, Bronchiectasis)

Which organism is most frequently isolated from the sputum of adults with stable bronchiectasis in most cohorts?

  1. Mycobacterium tuberculosis
  2. Pneumocystis jirovecii
  3. Haemophilus influenzae Correct answer.
  4. Aspergillus fumigatus

Explanation

Haemophilus influenzae is among the most commonly recovered pathogens in stable bronchiectasis, along with Pseudomonas aeruginosa in more advanced disease. It colonises damaged airways and drives chronic inflammation. The other organisms are associated with specific settings rather than routine stable disease.

Question 49Obstructive Airway Diseases (Asthma, COPD, Bronchiectasis)

A patient with acute severe asthma has an arterial blood gas showing a PaCO2 of 6.5 kPa (49 mmHg) with a normal pH. How should this finding be interpreted?

  1. Reassurance that ventilation is adequate
  2. Evidence that the patient has developed COPD
  3. A sign of life-threatening deterioration requiring urgent escalation Correct answer.
  4. An expected finding in mild asthma

Explanation

In acute asthma, hyperventilation normally lowers PaCO2. A rising or normal PaCO2 indicates the patient is tiring and signals imminent respiratory failure. This mandates urgent escalation of therapy and consideration of ventilatory support.

Question 50Obstructive Airway Diseases (Asthma, COPD, Bronchiectasis)

Which inhaler technique error most reduces lung deposition of a pressurised metered-dose inhaler when used without a spacer?

  1. Shaking the device before each actuation
  2. Activating the canister before the start of inspiration Correct answer.
  3. Exhaling fully before actuation
  4. Holding the breath for ten seconds after inhalation

Explanation

Coordination between actuation and inhalation is critical with a metered-dose inhaler. Firing the canister before inspiration begins causes much of the dose to impact the oropharynx rather than reach the airways. A spacer removes this coordination requirement.