Atelectasis and Acute Lung Injury — MCQs
In acute respiratory distress syndrome (ARDS), which type of cell is primarily damaged?
A male patient is not responding to oxygen therapy and has been diagnosed with ARDS (Acute Respiratory Distress Syndrome). What is the role of IL-8 in ARDS?
Which of the following conditions is characterized by the presence of hyaline deposits in alveolar walls?
All of the following may lead to pneumatocele formation except which of the following?
A patient with a known case of acute pancreatitis develops breathlessness and bilateral basal crepitations on day 4. What is the most likely diagnosis based on the chest radiography image?
What is the most common complication of blood transfusion that can lead to death?
About Transfusion-Related Acute Lung Injury (TRALI), all of the following are true except:
TRALI occurs within how many hours of transfusion?
Blood transfusion associated acute lung injury occurs due to -
Thoracotomy is indicated in all the following conditions except:
Atelectasis and Acute Lung Injury Indian Medical PG Practice Questions and MCQs
Question 1: In acute respiratory distress syndrome (ARDS), which type of cell is primarily damaged?
- A. Type 2 pneumocytes
- B. Type 1 pneumocytes (Correct Answer)
- C. Alveolar macrophages
- D. Bronchial epithelial cells
Explanation: ***Type 1 pneumocytes*** - These cells form an **extensive network of thin cells** that cover approximately 95% of the alveolar surface and are primarily responsible for **gas exchange** [4]. - Their thinness and large surface area make them particularly vulnerable to injury during the **initial inflammatory phase of ARDS**, leading to increased permeability and alveolar edema [1]. *Type 2 pneumocytes* - While important for producing **surfactant** and differentiating into Type 1 pneumocytes during repair, Type 2 cells are generally **more resistant to acute injury** than Type 1 cells [2]. - They play a role in the **repair phase** of ARDS, regenerating damaged alveolar epithelium [2]. *Alveolar macrophages* - These are **immune cells** that reside in the alveoli, primarily responsible for **phagocytosis** of foreign particles and initiating immune responses [3]. - While they are activated and contribute to the inflammation in ARDS, they are not the primary cells damaged in the early stages as the epithelial barrier cells are [1]. *Bronchial epithelial cells* - These cells line the airways (bronchi and bronchioles) and are involved in **mucociliary clearance** [3]. - While severe lung injury can extend to these areas, the hallmark of ARDS is damage primarily to the **alveolar-capillary membrane**, not the larger airways.
Question 2: A male patient is not responding to oxygen therapy and has been diagnosed with ARDS (Acute Respiratory Distress Syndrome). What is the role of IL-8 in ARDS?
- A. Endothelial cell activation
- B. Recruitment of neutrophils (Correct Answer)
- C. Macrophage activation
- D. Promote surfactant production
Explanation: Recruitment of neutrophils - **Interleukin-8 (IL-8)**, also known as **CXCL8**, is a powerful **chemotactic cytokine** that primarily attracts and activates neutrophils [3]. - In **ARDS**, this recruitment leads to an influx of neutrophils into the pulmonary interstitium and alveolar spaces, contributing to inflammation and lung injury [1]. *Endothelial cell activation* - While other **cytokines** and inflammatory mediators can activate **endothelial cells** in ARDS [2], IL-8's primary role is not direct endothelial activation but rather **neutrophil chemotaxis** [3]. - **Endothelial cell activation** leads to increased vascular permeability and leukocyte adherence, which is often a consequence of overall inflammation, not solely IL-8 [4]. *Macrophage activation* - **Macrophages** are activated by various stimuli and other **cytokines**, such as **TNF-alpha** and **IFN-gamma**, as part of the inflammatory response. - While macrophages produce IL-8, its main function is not to activate macrophages themselves but to attract **neutrophils**. *Promote surfactant production* - **Surfactant production** is primarily regulated by **Type II pneumocytes** and is often impaired in ARDS due to damage to these cells [1]. - IL-8 is a **pro-inflammatory cytokine** and plays no direct role in promoting surfactant synthesis; in fact, its inflammatory effects can indirectly worsen surfactant dysfunction. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, p. 681. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, p. 679. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 87-89. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Migration in the tissues toward a chemotactic stimulus, pp. 86-87.
Question 3: Which of the following conditions is characterized by the presence of hyaline deposits in alveolar walls?
- A. Asthma
- B. Hyaline membrane disease (Correct Answer)
- C. Chronic bronchitis
- D. Interstitial lung disease
Explanation: ***Hyaline membrane disease*** - This condition is pathologically characterized by the presence of **eosinophilic (hyaline) membranes** lining the distal airspaces, which are composed of fibrin, cellular debris, and necrotic cells [1]. - These **hyaline deposits obstruct gas exchange** and are a hallmark of **acute lung injury** in neonates due to surfactant deficiency [2]. *Asthma* - Characterized by **bronchoconstriction**, **mucus plugging**, and **airway inflammation**, but not hyaline deposits in alveolar walls. - Pathologically, there is hyperplasia of goblet cells, hypertrophy of bronchial smooth muscle, and eosinophilic infiltration. *Chronic bronchitis* - Defined by **chronic productive cough** due to hypertrophy of mucous glands and increased mucus production in the bronchi, not alveolar hyaline deposits. - It primarily affects the **large airways** and is associated with chronic inflammation and airway obstruction. *Interstitial lung disease* - Involves inflammation and fibrosis of the **interstitium of the lung**, leading to impaired gas exchange. - While it causes architectural distortion, **hyaline deposits** in the alveolar walls are not a defining pathological feature. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 679-681. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, p. 466.
Question 4: All of the following may lead to pneumatocele formation except which of the following?
- A. Staphylococcal pneumonia
- B. Positive pressure ventilation
- C. Hydrocarbon inhalation
- D. ARDS (Correct Answer)
Explanation: ***ARDS*** - **Acute Respiratory Distress Syndrome (ARDS)** is primarily characterized by **inflammatory lung injury**, leading to **alveolar edema**, but does not typically cause pneumatocele formation [1]. - Pneumatoceles are more likely associated with infections or mechanical ventilation, not with ARDS itself. *Staphylococcal pneumonia* - **Staphylococcal pneumonia** can lead to pneumatocele formation due to **necrotizing pneumonia**, where the formation of air-filled cysts occurs from lung tissue damage. - This type of pneumonia is associated with **Staphylococcus aureus** and can cause cavitary lesions. *Positive pressure ventilation* - **Positive pressure ventilation** can increase the risk of barotrauma, leading to the formation of pneumatocele through excess air entering lung tissue. - It is often used in cases of respiratory distress but can inadvertently contribute to pneumatocele development. *Hydrocarbon inhalation* - **Hydrocarbon inhalation** is linked to pneumonitis and can cause lung injury, leading to the formation of **pneumatoceles** as a result of **lung inflammation**. - Such inhalation can create **alveolar damage**, allowing for air-filled spaces to develop.
Question 5: A patient with a known case of acute pancreatitis develops breathlessness and bilateral basal crepitations on day 4. What is the most likely diagnosis based on the chest radiography image?
- A. Bilateral pneumonia
- B. Carcinogenic Pulmonary Embolism
- C. Lung collapse (atelectasis)
- D. Acute Respiratory Distress Syndrome (ARDS) (Correct Answer)
Explanation: ***Acute Respiratory Distress Syndrome (ARDS)*** - The chest radiograph shows **bilateral patchy infiltrates** and **diffuse alveolar opacities** consistent with ARDS, especially in the context of **acute pancreatitis** as a known risk factor. - The development of **breathlessness** and **bilateral basal crepitations** (rales) on day 4 further supports ARDS due to fluid accumulation in the lungs. *Bilateral pneumonia* - While pneumonia can cause bilateral infiltrates, the **symmetrical and widespread distribution** seen on this radiograph, combined with the context of acute pancreatitis, makes ARDS a more likely diagnosis. - Pneumonia typically presents with fever, productive cough, and lung consolidation, which are not specifically highlighted as primary symptoms over the breathlessness. *Carcinogenic Pulmonary Embolism* - Pulmonary embolism typically manifests with **sudden onset dyspnea**, pleuritic chest pain, and sometimes hemoptysis, and chest X-rays are often normal or show subtle findings like a **Westermark sign** or Hampton's hump. - The widespread bilateral infiltrates seen in the image are **not characteristic of pulmonary embolism**. *Lung collapse (atelectasis)* - Atelectasis usually appears as a ** localised area of increased opacification**, often with volume loss (e.g., tracheal deviation, elevated hemidiaphragm), and is often unilateral or segmental. - The **diffuse, bilateral, and often fluffy infiltrates** seen in this image are not consistent with typical atelectasis.
Question 6: What is the most common complication of blood transfusion that can lead to death?
- A. Hyperkalemia
- B. Citrate toxicity
- C. T.R.A.L.I (Correct Answer)
- D. Hypothermia
Explanation: ***T.R.A.L.I*** - **Transfusion-Related Acute Lung Injury (TRALI)** is the leading cause of transfusion-related mortality, characterized by sudden onset of **non-cardiogenic pulmonary edema** within 6 hours of transfusion [1]. - It is thought to be mediated by **donor antibodies** that activate recipient neutrophils in the pulmonary vasculature, leading to capillary leakage [1]. *Hyperkalemia* - Can occur, especially in massive transfusions or rapid infusion of stored blood, but it is less common and typically less lethal than TRALI [1]. - Often manageable with interventions to shift potassium intracellularly or remove it from the body. *Citrate toxicity* - Associated with **massive transfusions** or in patients with **liver dysfunction**, as the liver metabolizes citrate. - Leads to **hypocalcemia** due to citrate chelating calcium, but is rarely fatal and reversible with calcium administration. *Hypothermia* - Can occur with rapid infusion of large volumes of cold blood products, particularly in trauma or surgical settings. - While it can exacerbate coagulopathy and arrhythmias, it is generally preventable with blood warmers and rarely a direct cause of death compared to TRALI.
Question 7: About Transfusion-Related Acute Lung Injury (TRALI), all of the following are true except:
- A. Steroids have a doubtful role in management
- B. Mortality is less than 10%
- C. Signs and symptoms usually subside within 2-3 weeks of onset (Correct Answer)
- D. Supportive care is the mainstay of treatment
Explanation: ***Signs and symptoms usually subside within 2-3 weeks of onset*** - TRALI is characterized by **acute onset**, typically within 6 hours of transfusion, and symptoms often resolve within **48-96 hours**. - A resolution period of **2-3 weeks** is significantly longer than the typical course for TRALI, suggesting a different underlying process. *Supportive care is the mainstay of treatment* - **Supportive care**, including oxygen therapy and mechanical ventilation if needed, is indeed the primary treatment for TRALI. - There is no specific antidote or targeted therapy for TRALI, making symptomatic management crucial. *Steroids have a doubtful role in management* - The use of **corticosteroids** in TRALI management is **controversial** and generally not recommended. - Current evidence does not support their routine use, and they are typically reserved for specific situations or not used at all. *Mortality is less than 10%* - While TRALI is a serious complication, its **mortality rate has significantly decreased** over the years due to improved recognition and mitigation strategies, now typically ranging from 5-10%. - This statement is generally considered true in contemporary medical practice.
Question 8: TRALI occurs within how many hours of transfusion?
- A. 6 hours (Correct Answer)
- B. 48 hours
- C. 72 hours
- D. 12 hours
Explanation: ***6 hours*** - **Transfusion-related acute lung injury (TRALI)** is defined as new acute lung injury occurring during or within **6 hours** after the completion of a blood transfusion [1]. - It is a severe and potentially life-threatening transfusion reaction characterized by **acute respiratory distress**, **hypoxemia**, and **bilateral pulmonary infiltrates** on chest imaging [1]. *48 hours* - While other transfusion reactions or complications may manifest within 48 hours, TRALI has a more **acute onset**, typically within the first 6 hours. - A pulmonary event occurring between 6 and 48 hours post-transfusion might be considered **delayed TRALI** or another diagnosis like **transfusion-associated circulatory overload (TACO)**, but the classic definition refers to the 6-hour window. *72 hours* - Reactions occurring 72 hours after transfusion are generally considered **delayed transfusion reactions**, which include conditions like **delayed hemolytic transfusion reactions** or **post-transfusion purpura**. - This timeframe is too long for the typical presentation of TRALI, which is characterized by rapid onset. *12 hours* - Although 12 hours falls within an acute window, the most commonly accepted and diagnostically crucial timeframe for TRALI is **within 6 hours** of transfusion. - A reaction occurring between 6 and 12 hours would still be considered suspiciously TRALI, but the strict definition emphasizes the earlier onset.
Question 9: Blood transfusion associated acute lung injury occurs due to -
- A. Nosocomial infections
- B. Auto-immune disorder
- C. Genetic susceptibility
- D. HLA-mediated reaction (Correct Answer)
Explanation: ***HLA-mediated reaction*** - Transfusion-related acute lung injury (TRALI) is primarily caused by **antibodies** in the donor plasma (usually anti-HLA or anti-HNA antibodies) reacting with the recipient's **neutrophils** [1]. - This interaction leads to neutrophil activation and sequestration in the pulmonary vasculature, causing **endothelial damage** and increased capillary permeability [1]. *Nosocomial infections* - Nosocomial infections are **hospital-acquired infections** and are not a direct cause of TRALI. - While infections can lead to lung injury, the mechanism of TRALI is distinct and immunologically mediated by donor antibodies. *Auto-immune disorder* - An autoimmune disorder involves the body's immune system attacking its own tissues, which is not the primary mechanism of TRALI. - TRALI is an **alloimmune reaction** where donor antibodies react with host antigens, rather than a pre-existing autoimmune condition. *Genetic susceptibility* - While genetic factors might sometimes play a role in an individual's general inflammatory response or susceptibility to certain conditions, they are **not the direct or primary cause** of TRALI. - The acute lung injury in TRALI is triggered by specific **antibody-antigen interactions** during the transfusion.
Question 10: Thoracotomy is indicated in all the following conditions except:
- A. Rapidly accumulating haemothorax
- B. Massive air leak
- C. Pulmonary contusion (Correct Answer)
- D. Penetrating chest injuries
Explanation: ***Pulmonary contusion*** - **Pulmonary contusion** is a bruise of the lung parenchyma that typically resolves with **supportive care** (oxygen, fluid management, analgesia, respiratory support) [1]. - It is generally *not* an indication for thoracotomy and is managed **conservatively** in most cases [1]. - Surgical intervention is only considered if complicated by other issues such as **uncontrolled hemorrhage**, massive hemothorax, or other injuries requiring exploration. *Penetrating chest injuries* - While approximately **85% of penetrating chest injuries** are managed conservatively with tube thoracostomy alone, **selective indications** for thoracotomy include: - **Cardiac tamponade** or suspected cardiac injury - **Great vessel injury** with hemodynamic instability - **Massive initial hemothorax** (>1500 mL) or persistent bleeding (>200 mL/hr) - **Trans-mediastinal trajectory** with suspected esophageal or major vascular injury - The key is that *specific criteria* determine need for thoracotomy, not the penetrating injury itself. *Rapidly accumulating haemothorax* - A **rapidly accumulating haemothorax** with **>1500 mL initial output** or **>200 mL/hour for 2-4 consecutive hours** indicates significant ongoing intrathoracic bleeding. - This is an **absolute indication** for thoracotomy for **source identification and hemorrhage control** [2]. - Without surgical intervention, such bleeding leads to **hemodynamic instability**, shock, and death. *Massive air leak* - A **massive persistent air leak** from chest tube, unresponsive to initial management, suggests a large **tracheobronchial injury** or major lung parenchymal disruption [3]. - This persistent leak prevents **lung re-expansion** and adequate ventilation. - Thoracotomy is indicated for **surgical repair** of the damaged bronchus, major airway, or extensive lung laceration [2].
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free