Pulmonology Practice Questions

Q: What is the most common cause of pulmonary embolism?

Thrombosis of leg veins. **Explanation:** **1. Why Option A is Correct:** Pulmonary Embolism (PE) is most commonly a complication of **Deep Vein Thrombosis (DVT)** [1]. Approximately 90% of all pulmonary emboli originate from the deep veins of the lower extremities. Specifically, thrombi originating in the **proximal leg veins** (popliteal, femoral, and iliac veins) are the most likely to embolize to the pulmonary arteries due to their large caliber and high blood flow. **2. Why the Other Options are Incorrect:** * **Option B & C:** While thrombosis of the prostatic veins or the Inferior Vena Cava (IVC) can lead to PE, they represent a much smaller percentage of cases compared to leg veins. IVC thrombosis is usually a secondary extension of lower limb DVT rather than a primary isolated cause. * **Option D:** Thrombosis of the internal pudendal **artery** cannot cause a pulmonary embolism. Emboli to the lungs must originate in the **venous system** or the right side of the heart to reach the pulmonary circulation. Arterial thrombi lead to localized ischemia or distal systemic infarction (e.g., stroke), not PE. **3. Clinical Pearls for NEET-PG:** * **Most common site:** Proximal deep veins of the leg (above the knee) are higher risk than calf veins. * **Virchow’s Triad:** The pathophysiology of DVT/PE involves Stasis, Endothelial Injury, and Hypercoagulability. * **Gold Standard Investigation:** CT Pulmonary Angiography (CTPA) is the investigation of choice for PE. * **ECG Finding:** The most common ECG finding is **Sinus Tachycardia**, while the most specific (though rare) is the **S1Q3T3 pattern**. * **Chest X-ray:** Usually normal, but may show **Hampton’s Hump** (wedge-shaped opacity) or **Westermark sign** (focal oligemia).

Q: A 60-year-old hypertensive male had a stroke 2 weeks prior to a sudden attack of dyspnea. The present ECG shows changes of S1 Q3 T3, and the V/Q pulmonary scan shows major areas of reduced perfusion. What is the probable diagnosis?

Pulmonary thromboembolism. ### Explanation **Correct Option: C. Pulmonary thromboembolism (PTE)** The clinical scenario presents a classic triad for Pulmonary Thromboembolism: 1. **Risk Factors:** The patient had a stroke 2 weeks ago, implying prolonged immobilization (Virchow’s Triad: Stasis) [2]. 2. **ECG Findings:** The **S1Q3T3 pattern** (prominent S wave in Lead I, Q wave and inverted T wave in Lead III) is a classic, though non-specific, sign of acute right heart strain seen in massive PTE [1]. 3. **V/Q Scan:** The presence of "major areas of reduced perfusion" with normal ventilation (implied mismatch) is the hallmark of PTE [1]. **Analysis of Incorrect Options:** * **A. Pneumothorax:** While it causes sudden dyspnea, it would typically present with pleuritic chest pain and hyper-resonance on percussion. ECG changes like S1Q3T3 and V/Q perfusion defects are not characteristic [3]. * **B. Congestive Cardiac Failure (CCF):** CCF usually presents with bilateral basal crepitations and orthopnea. A V/Q scan in CCF would show patchy, non-segmental defects rather than major perfusion-specific deficits [3]. * **D. Psychogenic dysfunction:** This is a diagnosis of exclusion. The objective ECG and V/Q scan findings definitively point toward an organic vascular pathology [3]. **High-Yield Pearls for NEET-PG:** * **Most common ECG finding in PTE:** Sinus tachycardia (S1Q3T3 is specific but less common) [1]. * **Gold Standard Investigation:** CT Pulmonary Angiography (CTPA). * **Chest X-ray signs:** Westermark sign (focal oligemia) and Hampton’s Hump (wedge-shaped opacity) [1]. * **Wells Score:** Used clinically to predict the probability of PE before ordering investigations. * **Treatment of Choice:** Hemodynamically stable patients are started on LMWH/Fondaparinux; unstable patients (massive PE) require thrombolysis [2].

Q: A 23-year-old woman presents with wheezing symptoms and shortness of breath on exertion, occurring primarily in the spring and resolving spontaneously. She is a nonsmoker with no personal or family history of atopy or asthma. Physical examination reveals normal vital signs and cardiac findings, with clear lungs on auscultation and no wheezing on forced expiration. What is the most likely mechanism of wheezing in this patient?

Nonspecific hyperirritability of the tracheobronchial tree. ### Explanation The patient presents with symptoms suggestive of **Intrinsic (Non-atopic) Asthma**. The hallmark of all forms of asthma, regardless of the trigger, is **nonspecific hyperirritability of the tracheobronchial tree** [1]. **1. Why Option C is Correct:** In this clinical scenario, the patient lacks a personal or family history of atopy (no eczema, allergic rhinitis, or hay fever) and has normal IgE levels (implied by the absence of atopy). This points toward intrinsic asthma [2]. The underlying pathophysiology in these patients involves an exaggerated bronchoconstrictor response to various stimuli (like cold air, exercise, or seasonal irritants). This "hyper-responsiveness" or "hyperirritability" is the physiological basis of the airway narrowing that leads to wheezing and dyspnea [1]. **2. Why Other Options are Incorrect:** * **Options A, B, and D:** These are all components of **Extrinsic (Atopic) Asthma**. This type is characterized by a Type I hypersensitivity reaction (disordered immediate hypersensitivity) mediated by IgE [2]. In atopic individuals, exposure to specific allergens leads to IgE-mediated mast cell degranulation. Since this patient has no history of atopy, these mechanisms are less likely to be the primary driver of her symptoms. **Clinical Pearls for NEET-PG:** * **Asthma Triad (Samter’s Triad):** Asthma, Aspirin sensitivity, and Nasal polyposis (a classic form of non-atopic asthma) [2]. * **Diagnosis:** The gold standard for diagnosing bronchial asthma is **Spirometry**, showing reversible airway obstruction (increase in FEV1 >12% and >200ml after bronchodilator). * **Methacholine Challenge:** Used when asthma is suspected but spirometry is normal; it specifically tests for the "bronchial hyper-responsiveness" mentioned in Option C [1]. * **Physical Exam:** A normal lung exam does not rule out asthma, as symptoms are often episodic and paroxysmal [3].

Q: A 63-year-old woman presents with acute shortness of breath. She has a recent diagnosis of breast cancer and is undergoing active treatment. Her vital signs are: blood pressure 120/80 mm Hg, pulse 100/min. Cardiac and pulmonary examinations are normal. There are no clinical signs of deep venous thrombosis (DVT). Which of the following investigations is most likely to rule out a pulmonary embolism (PE)?

Normal ventilation-perfusion lung scan. **Explanation:** The patient presents with acute dyspnea and a high-risk factor (active malignancy), raising suspicion for **Pulmonary Embolism (PE)**. In the diagnostic workup of PE, the goal of certain tests is to "rule out" the condition with high negative predictive value. **Why Option C is Correct:** A **Normal Ventilation-Perfusion (V/Q) scan** essentially excludes the diagnosis of pulmonary embolism [2]. It has a very high negative predictive value (nearly 100%). If the distribution of radioactive tracer is uniform throughout the lung fields in both ventilation and perfusion phases, the probability of PE is clinically insignificant, regardless of the pre-test probability [2]. **Analysis of Incorrect Options:** * **A & B (Normal CXR and ECG):** These are frequently normal in patients with PE [1]. A normal CXR is actually a common finding (or may show non-specific signs like atelectasis) [1]. Similarly, the most common ECG finding in PE is sinus tachycardia; a completely normal ECG does not rule out the diagnosis [1]. * **D (Normal Ventilation Scan):** A ventilation scan alone only assesses airway patency. PE is a "perfusion defect" with preserved ventilation (mismatch). A normal ventilation scan does not provide information about the pulmonary vasculature. **NEET-PG High-Yield Pearls:** * **Gold Standard Investigation:** CT Pulmonary Angiography (CTPA) is the current investigation of choice for most patients [2]. * **V/Q Scan Indications:** Preferred in patients with **renal failure** (high creatinine), **contrast allergy**, or sometimes in **pregnancy** (lower fetal radiation dose compared to CTPA) [2]. * **D-Dimer:** Useful only to rule out PE in patients with **low/intermediate clinical probability** (Wells' Score). It has high sensitivity but low specificity. * **ECG Sign:** While sinus tachycardia is most common, the classic (but rare) sign is **S1Q3T3** [1].

Q: Which of the following is NOT a characteristic of ARDS?

Ability to maintain PaO2 on 100% oxygen. **Explanation:** Acute Respiratory Distress Syndrome (ARDS) is characterized by acute-onset respiratory failure resulting from non-cardiogenic pulmonary edema. **Why Option B is correct:** The hallmark pathophysiology of ARDS is a **significant right-to-left intrapulmonary shunt**. In ARDS, alveoli are filled with fluid or have collapsed (atelectasis), meaning blood perfusing these areas never comes into contact with alveolar gas. Because this blood bypasses ventilated units, increasing the Fraction of Inspired Oxygen (FiO2) to 100% fails to significantly improve the partial pressure of arterial oxygen (PaO2). This is known as **refractory hypoxemia**, making the "ability to maintain PaO2" a false statement regarding ARDS. **Why the other options are incorrect:** * **A. Dyspnea:** This is the primary clinical symptom. Patients present with severe respiratory distress, tachypnea, and increased work of breathing due to low lung compliance. * **C. Bilateral crepitations:** On physical examination, diffuse crackles (crepitations) are typically heard due to the presence of alveolar fluid. * **D. Bilateral opacities on X-ray:** According to the **Berlin Criteria**, the presence of bilateral opacities on chest imaging (X-ray or CT) that are not fully explained by effusions, collapse, or nodules is a mandatory diagnostic requirement. **NEET-PG High-Yield Pearls:** * **Berlin Criteria:** 1) Acute onset (within 1 week); 2) Bilateral opacities; 3) Pulmonary edema not explained by heart failure (PCWP <18 mmHg); 4) PaO2/FiO2 ratio <300. * **Severity:** Mild (200–300), Moderate (100–200), Severe (<100). * **Management:** Low tidal volume ventilation (6 mL/kg) is the gold standard to prevent Volutrauma. * **Pathology:** The characteristic histological finding is **Diffuse Alveolar Damage (DAD)** with hyaline membrane formation.

Q: Which of the following is false regarding the CURB-65 criteria used to assess pneumonia severity?

Systolic blood pressure <= 100 mmHg. The **CURB-65 score** is a validated clinical prediction rule used to determine the severity of Community-Acquired Pneumonia (CAP) and guide the site of care (outpatient vs. inpatient vs. ICU) [1]. ### **Why Option C is the Correct Answer (The False Statement)** In the CURB-65 criteria, the threshold for **hypotension** is defined as a **Systolic Blood Pressure (SBP) 7 mmol/L:** This is a correct component (**U**rea) [1]. In mg/dL, this corresponds to > 19 mg/dL. * **B. Respiratory rate ≥ 30 breaths/min:** This is a correct component (**R**espiratory rate) indicating significant respiratory distress. * **D. Diastolic blood pressure ≤ 60 mmHg:** This is a correct component (**B**lood pressure) representing hemodynamic instability. ### **The CURB-65 Breakdown** Each criteria carries 1 point [1]: 1. **C**onfusion (new onset) 2. **U**rea > 7 mmol/L (19 mg/dL) 3. **R**espiratory Rate ≥ 30/min 4. **B**lood Pressure (SBP < 90 or DBP ≤ 60 mmHg) 5. **Age ≥ 65** years ### **High-Yield Clinical Pearls for NEET-PG** * **Management Guide:** * **Score 0-1:** Low risk; consider outpatient treatment [1]. * **Score 2:** Moderate risk; consider short-stay inpatient observation [1]. * **Score ≥ 3:** Severe pneumonia; requires hospitalization (consider ICU if score is 4-5) [1]. * **CRB-65:** A modified version used in primary care settings where urea testing is unavailable. * **Limitation:** CURB-65 does not account for comorbidities or oxygenation (unlike the PSI/PORT score), which are also critical in management decisions.

Question 1

What is the most common cause of pulmonary embolism?

Accepted Answer

Thrombosis of leg veins

Answer

Thrombosis of prostatic veins

Answer

Inferior vena cava thrombosis

Answer

Thrombosis of internal pudendal artery

Question 2

A 60-year-old hypertensive male had a stroke 2 weeks prior to a sudden attack of dyspnea. The present ECG shows changes of S1 Q3 T3, and the V/Q pulmonary scan shows major areas of reduced perfusion. What is the probable diagnosis?

Accepted Answer

Pulmonary thromboembolism

Answer

Pneumothorax

Answer

Congestive cardiac failure

Answer

Psychogenic dysfunction

Question 3

A 23-year-old woman presents with wheezing symptoms and shortness of breath on exertion, occurring primarily in the spring and resolving spontaneously. She is a nonsmoker with no personal or family history of atopy or asthma. Physical examination reveals normal vital signs and cardiac findings, with clear lungs on auscultation and no wheezing on forced expiration. What is the most likely mechanism of wheezing in this patient?

Accepted Answer

Nonspecific hyperirritability of the tracheobronchial tree

Answer

Elevated IgE levels

Answer

Mast cell instability

Answer

Disordered immediate hypersensitivity

Question 4

A 63-year-old woman presents with acute shortness of breath. She has a recent diagnosis of breast cancer and is undergoing active treatment. Her vital signs are: blood pressure 120/80 mm Hg, pulse 100/min. Cardiac and pulmonary examinations are normal. There are no clinical signs of deep venous thrombosis (DVT). Which of the following investigations is most likely to rule out a pulmonary embolism (PE)?

Accepted Answer

Normal ventilation-perfusion lung scan

Answer

Normal chest X-ray

Answer

Normal electrocardiogram (ECG)

Answer

Normal ventilation scan

Question 5

Which of the following is a clinical sign of tension pneumothorax?

Accepted Answer

Tracheal deviation to the contralateral side

Answer

Dullness to percussion

Answer

Increased breath sounds

Answer

Increased tactile vocal fremitus

Question 6

Which of the following is NOT a characteristic of ARDS?

Accepted Answer

Ability to maintain PaO2 on 100% oxygen

Answer

Dyspnea

Answer

Bilateral crepitations

Answer

Bilateral opacities on X-ray

Question 7

Which of the following features would be seen in a patient with suspected aspergillosis?

Accepted Answer

Serum precipitins for Aspergillus

Answer

Elevated serum IgE

Answer

Peripheral eosinophilia

Answer

All of the above

Question 8

Which of the following is false regarding the CURB-65 criteria used to assess pneumonia severity?

Accepted Answer

Systolic blood pressure <= 100 mmHg

Answer

Blood urea nitrogen > 7 mmol/L

Answer

Respiratory rate >= 30 breaths/min

Answer

Diastolic blood pressure <= 60 mmHg

Question 9

What is the major risk factor for the development of a lung abscess?

Accepted Answer

Aspiration

Answer

Pneumonia

Answer

Lung cancer

Answer

Tuberculosis

Question 10

A 25-year-old man presents with a progressive illness of several days' duration characterized by nonproductive cough, fever, and malaise. A lateral view chest radiograph reveals platelike atelectasis. Elevated titers of cold agglutinins are detected. Which of the following is the most likely type of pneumonia in this patient?

Accepted Answer

Interstitial pneumonia, most likely caused by M. pneumoniae

Answer

Bacterial pneumonia, most likely caused by S. pneumoniae

Answer

Hospital-acquired pneumonia, most likely caused by P. aeruginosa

Answer

P. jiroveci (carinii) pneumonia, most likely related to an immunocompromised state

Pulmonology — MCQs

Pulmonology — MCQs

On this page

Practice by Chapter

Want unlimited practice?