Pulmonary Function Testing — MCQs
Which of the following is used for the diagnosis of asthma?
A 60-year-old male with COPD has FEV1 45% predicted, mMRC grade 2 dyspnea, and 2 exacerbations last year. Which GOLD category?
In patients with emphysematous bullae, total lung volume is best determined by?
Which of the following statements about the contraction stress test (CST) is MOST accurate?
Pulmonary plethora in a child presenting with cyanosis, is seen in?
Which of the following is not associated with primary ciliary dyskinesia?
What is a key diagnostic criterion for acute respiratory distress syndrome (ARDS) in a child?
A patient of Scleroderma presents with acute respiratory distress. Chest X-ray shows B/L reticular basilar shadows. What is the next line of investigation in this patient?
A lady presents with complaints of hemoptysis, and her chest X-ray appears to be normal. What is the next best investigation?
Match List-I with List-II and select the correct answer using the code given below the Lists:
Pulmonary Function Testing Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following is used for the diagnosis of asthma?
- A. Measurement of tidal volume
- B. End expiratory flow rate
- C. Total lung capacity
- D. FEV1 (Correct Answer)
Explanation: ***FEV1*** - **Forced expiratory volume in 1 second (FEV1)** is the gold standard spirometric parameter for asthma diagnosis - Key diagnostic criteria include: - Reduced **FEV1/FVC ratio** (<0.70 or <0.75-0.80 in adults) - **Bronchodilator reversibility**: ≥12% and ≥200 mL increase in FEV1 after inhaled short-acting β2-agonist - This reversibility distinguishes asthma from fixed obstructive diseases like COPD - Serial **peak expiratory flow (PEF)** monitoring can also demonstrate variability characteristic of asthma *Measurement of tidal volume* - **Tidal volume** measures the amount of air inhaled or exhaled during normal breathing (typically ~500 mL at rest) - Not a diagnostic parameter for asthma as it doesn't assess **airway obstruction** or **hyperresponsiveness** - May be reduced during acute exacerbations but lacks specificity for asthma diagnosis *End expiratory flow rate* - Not a standard diagnostic parameter for asthma - While **mid-expiratory flow rates** (FEF25-75%) and **peak expiratory flow (PEF)** are assessed, **FEV1** remains the primary diagnostic measure - FEV1 provides better reproducibility and standardization for diagnosis *Total lung capacity* - **Total lung capacity (TLC)** represents total lung volume after maximal inhalation - May be normal or increased in asthma due to **air trapping** and hyperinflation - Not used as a primary diagnostic criterion as asthma diagnosis focuses on demonstrating **reversible airflow limitation**, not lung volumes
Question 2: A 60-year-old male with COPD has FEV1 45% predicted, mMRC grade 2 dyspnea, and 2 exacerbations last year. Which GOLD category?
- A. GOLD A
- B. GOLD D (Correct Answer)
- C. GOLD B
- D. GOLD C
Explanation: Gold D - This patient meets criteria for **GOLD D** due to both high symptom burden (mMRC grade 2 dyspnea) and a high risk of exacerbations (2 exacerbations last year) [1]. - COPD severity in GOLD D is characterized by an **FEV1 < 50% predicted** (in this case, 45%) along with significant symptoms and/or frequent exacerbations [1]. *GOLD A* - **GOLD A** patients have low symptom burden (mMRC 0-1 or CAT < 10) and a low risk of exacerbations (0-1 exacerbations not leading to hospitalization) [1]. - This patient's **mMRC grade 2** and **2 exacerbations** last year exclude him from GOLD A. *GOLD B* - **GOLD B** patients have a high symptom burden (mMRC ≥ 2 or CAT ≥ 10) but a low risk of exacerbations (0-1 exacerbations not leading to hospitalization) [1]. - This patient's **2 exacerbations** last year place him in a higher risk category than GOLD B. *GOLD C* - **GOLD C** patients have a low symptom burden (mMRC 0-1 or CAT < 10) but a high risk of exacerbations (≥ 2 exacerbations or ≥ 1 leading to hospitalization) [1]. - This patient's **mMRC grade 2** indicates a high symptom burden, which is not characteristic of GOLD C.
Question 3: In patients with emphysematous bullae, total lung volume is best determined by?
- A. Spirometry
- B. Any of the above
- C. Helium dilution method
- D. Plethysmography (Correct Answer)
Explanation: ***Plethysmography*** - This method accurately measures **total lung capacity (TLC)**, functional residual capacity (FRC), and residual volume (RV) by determining the **volume of gas in the thorax**. - It is particularly useful in conditions like **emphysema** with air trapping and bullae, as it accounts for **non-communicating air spaces** that other methods miss. *Spirometry* - Spirometry measures volumes of air that can be **exhaled or inhaled forcibly**, such as FVC and FEV1. - It cannot measure residual volume (RV) or total lung capacity (TLC) directly, especially in cases of **air trapping** where trapped air cannot be exhaled. *Helium dilution method* - The helium dilution method measures **communicating lung volumes**, like functional residual capacity (FRC), by assessing the dilution of a known concentration of helium after rebreathing. - In conditions with **emphysematous bullae** and air trapping, it **underestimates total lung volume** because it cannot measure air in non-communicating or poorly communicating spaces. *Any of the above* - Only plethysmography can accurately measure total lung volume in the presence of **emphysematous bullae** due to its ability to measure both communicating and non-communicating air spaces. - Spirometry and helium dilution methods would provide **inaccurate or incomplete measurements** in this clinical scenario.
Question 4: Which of the following statements about the contraction stress test (CST) is MOST accurate?
- A. Invasive method
- B. Detects fetal well being
- C. Negative test is associated with good fetal outcome (Correct Answer)
- D. Oxytocin is never used in the test
Explanation: ***Negative test is associated with good fetal outcome*** - A **negative CST** indicates that there are no late or significant variable decelerations in response to uterine contractions, suggesting the fetus can tolerate labor. - This finding is strongly correlated with **fetal well-being** and a low likelihood of fetal distress in the near future, with a **negative predictive value of approximately 99%**. *Invasive method* - The CST is considered a **non-invasive test**, as it involves external monitoring of fetal heart rate and uterine contractions. - No instruments are inserted into the body, differentiating it from truly invasive procedures like **amniocentesis**. *Detects fetal well being* - While the CST provides valuable information, it specifically assesses **uteroplacental function and fetal oxygenation reserve** during the stress of contractions, rather than comprehensive fetal well-being. - It identifies fetuses at risk for **uteroplacental insufficiency** but does not evaluate other parameters of fetal health. - Other tests like the **biophysical profile** offer a more comprehensive assessment of fetal well-being, including parameters like fetal breathing, movement, tone, and amniotic fluid volume. *Oxytocin is never used in the test* - **Oxytocin** is frequently used to induce uterine contractions if spontaneous contractions are insufficient for the test (oxytocin challenge test or OCT). - Alternatively, **nipple stimulation** can be used to achieve adequate contractions for the CST.
Question 5: Pulmonary plethora in a child presenting with cyanosis, is seen in?
- A. Coarctation of the aorta
- B. Total Anomalous Pulmonary Venous Connection (TAPVC) (Correct Answer)
- C. Tetralogy of Fallot (TOF)
- D. Tricuspid Atresia (TA)
Explanation: ***Total Anomalous Pulmonary Venous Connection (TAPVC)*** - In **non-obstructed TAPVC**, all pulmonary veins drain anomalously into the right atrium (or its tributaries) instead of the left atrium. - This causes **complete mixing of oxygenated pulmonary venous blood with deoxygenated systemic venous blood** in the right atrium → **cyanosis**. - Since an obligatory **atrial septal defect (ASD)** allows blood to reach the left heart, and there is **increased volume load on the right heart**, there is **increased pulmonary blood flow → pulmonary plethora** on chest X-ray. - Key point: **Obstructed TAPVC** causes pulmonary venous congestion and oligemia, NOT plethora. *Coarctation of the aorta* - **Coarctation of the aorta** is an **acyanotic** congenital heart disease involving systemic outflow obstruction. - It does **not cause cyanosis** unless there is differential cyanosis (lower body only) with a PDA and pulmonary hypertension causing right-to-left shunt. - Does not cause pulmonary plethora. *Tetralogy of Fallot (TOF)* - **Tetralogy of Fallot** presents with **cyanosis** due to right-to-left shunting through a VSD. - However, it has **pulmonary oligemia (decreased pulmonary blood flow)** due to right ventricular outflow tract obstruction and pulmonary stenosis. - Chest X-ray shows **boot-shaped heart** with decreased pulmonary vascular markings, NOT plethora. *Tricuspid Atresia (TA)* - **Tricuspid atresia** causes **cyanosis** due to obligatory right-to-left shunting at the atrial level. - Pulmonary blood flow is typically **decreased or normal** (depending on presence of VSD/PDA), NOT increased. - Does not typically cause pulmonary plethora.
Question 6: Which of the following is not associated with primary ciliary dyskinesia?
- A. Sinusitis
- B. Respiratory infection
- C. Sterility in males
- D. Hypothyroidism (Correct Answer)
Explanation: ***Hypothyroidism*** - **Hypothyroidism** is a condition related to the thyroid gland's function and is **not directly associated** with defects in ciliary structure or function. - While other systemic conditions can coexist, there is no known mechanistic link between primary ciliary dyskinesia and thyroid dysfunction. *Sterility in males* - **Sterility in males** is a common manifestation of primary ciliary dyskinesia, as the abnormal cilia impair **sperm motility**, preventing effective fertilization. - The **flagellum of sperm** shares structural similarities with cilia, and its dysfunction leads to **immotile spermatozoa**. *Sinusitis* - **Sinusitis** is a hallmark symptom of primary ciliary dyskinesia due to impaired ciliary clearance in the **paranasal sinuses**. - The inability to effectively clear mucus leads to chronic and recurrent **sinus infections** and inflammation. *Respiratory infection* - **Recurrent respiratory infections**, including bronchitis, pneumonia, and bronchiectasis, are characteristic features of primary ciliary dyskinesia. - Defective ciliary action in the **respiratory tract** prevents proper clearance of mucus and pathogens, leading to chronic infections.
Question 7: What is a key diagnostic criterion for acute respiratory distress syndrome (ARDS) in a child?
- A. Within 7 days of known clinical insult (Correct Answer)
- B. Respiratory failure not fully explained
- C. Left ventricular dysfunction
- D. All of the options
Explanation: ***Within 7 days of known clinical insult*** - A key diagnostic criterion for **Acute Respiratory Distress Syndrome (ARDS)** in children is the onset of respiratory symptoms within **7 days of a known clinical insult**. - This temporal relationship helps distinguish ARDS from other causes of respiratory failure that may have a more chronic or delayed onset. *Respiratory failure not fully explained* - **Respiratory failure not fully explained** by other conditions is a general characteristic but not a specific diagnostic criterion on its own. - ARDS requires the exclusion of cardiac failure as the primary cause of pulmonary edema, indicated by an absence of left atrial hypertension. *Left ventricular dysfunction* - **Left ventricular dysfunction** would suggest **cardiogenic pulmonary edema**, which needs to be excluded for a diagnosis of ARDS. - ARDS is characterized by **non-cardiogenic pulmonary edema**, meaning the fluid in the lungs is not due to heart failure. *All of the options* - This option is incorrect because **left ventricular dysfunction** is an *exclusion criterion* for ARDS, not a diagnostic criterion, as ARDS is defined by **non-cardiogenic pulmonary edema**. - While the other options relate to aspects of ARDS, only one is a key diagnostic criterion as formulated.
Question 8: A patient of Scleroderma presents with acute respiratory distress. Chest X-ray shows B/L reticular basilar shadows. What is the next line of investigation in this patient?
- A. High resolution CT to characterize the lung parenchyma. (Correct Answer)
- B. Pulmonary function tests to assess lung function.
- C. Contrast-enhanced CT scan for vascular assessment.
- D. Echocardiography to evaluate cardiac complications.
Explanation: ***High resolution CT*** - A **high-resolution CT (HRCT) scan** is the gold standard for evaluating **interstitial lung disease (ILD)**, which is commonly seen in **scleroderma** and presents with basilar reticular shadows on chest X-ray. - HRCT provides detailed images of the lung parenchyma, allowing for accurate characterization of the **fibrotic changes** and extent of ILD. *Pulmonary function tests to assess lung function.* - **Pulmonary function tests (PFTs)** provide functional information about lung capacity and gas exchange but do not offer detailed anatomical imaging of the lung parenchyma. - While essential for monitoring disease progression and severity, PFTs are not the primary diagnostic tool to further characterize the **reticular basilar shadows** seen on X-ray in an acute setting. *Contrast-enhanced CT scan for vascular assessment.* - A **contrast-enhanced CT scan** is primarily used to assess **vascular structures** or rule out conditions like **pulmonary embolism**, which is not directly indicated by the description of bilateral reticular basilar shadows. - The primary concern here is **interstitial lung disease**, which is best evaluated by **HRCT** without contrast. *Echocardiography to evaluate cardiac complications.* - **Echocardiography** is used to assess cardiac function and look for complications like **pulmonary hypertension** or **myocardial fibrosis**, which can occur in scleroderma. - However, it does not directly evaluate the **lung parenchyma** or the cause of the reticular basilar shadows.
Question 9: A lady presents with complaints of hemoptysis, and her chest X-ray appears to be normal. What is the next best investigation?
- A. Bronchoscopy for airway evaluation
- B. High-resolution CT scan of the chest (Correct Answer)
- C. Sputum cytology for malignancy detection
- D. Pulmonary function tests for lung assessment
Explanation: ***High-resolution CT scan of the chest*** - A **normal chest X-ray** does not rule out significant pulmonary pathology as it can miss small lesions, especially in cases of hemoptysis [1]. - An **HRCT scan** is more sensitive for detecting subtle parenchymal, airway, or vascular abnormalities that could be causing bleeding [1][2]. *Bronchoscopy for airway evaluation* - While bronchoscopy is a critical tool for investigating hemoptysis, performing an **HRCT first** helps localize the bleeding source or narrow down potential etiologies, guiding the bronchoscopist [1]. - Starting directly with bronchoscopy without prior imaging might miss **parenchymal lesions** not visible in the airways and increases procedural risk if the source is unknown. *Sputum cytology for malignancy detection* - **Sputum cytology** has a low sensitivity for detecting malignancy, especially if the lesion is not centrally located or actively shedding cells. - It is often reserved for patients with clear suspicion of cancer and usually follows imaging studies that indicate a suspicious mass [1]. *Pulmonary function tests for lung assessment* - **Pulmonary function tests** assess lung volumes, airflow, and gas exchange but do not diagnose the cause of hemoptysis. - These tests are primarily used for evaluating **respiratory mechanics** and the presence of obstructive or restrictive lung diseases, not acute bleeding.
Question 10: Match List-I with List-II and select the correct answer using the code given below the Lists:
- A. A→1 B→3 C→2 D→4 (Correct Answer)
- B. A→1 B→2 C→3 D→4
- C. A→3 B→2 C→4 D→1
- D. A→4 B→3 C→2 D→1
Explanation: ***A→1 B→3 C→2 D→4*** - Caroli's disease is characterized by **dilatation of intrahepatic bile ducts**, predisposing to **bile stasis**, stone formation, and recurrent **biliary sepsis** with associated abdominal pain. - Budd-Chiari Syndrome is defined by **hepatic venous outflow obstruction**, leading to symptoms like **ascites**, hepatomegaly, and abdominal pain. - Polycystic Liver Disease involves the presence of **multiple cysts in the liver**, which can cause **hepatomegaly** and **pain** due to the size and mass effect of the cysts. - Primary sclerosing cholangitis (PSC) is a **cholestatic liver disease** causing inflammation and fibrosis of the bile ducts, leading to **abnormal liver function tests** (elevated alkaline phosphatase and bilirubin) and often presenting with **jaundice**. *A→1 B→2 C→3 D→4* - This option incorrectly matches Budd-Chiari Syndrome with Hepatomegaly, Pain and Polycystic Liver Disease with Ascites. - The hallmark of Budd-Chiari is venous outflow obstruction leading to **ascites**, while **hepatomegaly and pain** are more characteristic symptoms of Polycystic Liver Disease due to the expanding cysts. *A→3 B→2 C→4 D→1* - This option incorrectly associates Caroli's disease with ascites and Primary Sclerosing Cholangitis with Abdominal pain, Biliary sepsis. - Caroli's disease is primarily characterized by **biliary complications** like cholangitis, not ascites, and ascites is a key feature of Budd-Chiari, not Polycystic Liver Disease. *A→4 B→3 C→2 D→1* - This option incorrectly links Caroli's disease with Abnormal LFT/jaundice generally and Primary Sclerosing Cholangitis with Abdominal pain, Biliary sepsis. - While Caroli's can cause abnormal LFTs and jaundice secondarily to cholangitis, its primary specific presentation involves **recurrent infection (biliary sepsis)**. Primary Sclerosing Cholangitis directly causes **abnormal LFTs and jaundice** due to cholestasis, but it is not commonly associated with abdominal pain and biliary sepsis.
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