Question
Total lung capacity is decreased in which one of the following conditions?
The correct answer is
Pulmonary fibrosis
Understanding Total Lung Capacity Changes
Total Lung Capacity (TLC) represents the maximum amount of air the lungs can hold after a maximal inhalation. Changes in TLC are key indicators of different lung pathologies.
Obstructive vs. Restrictive Lung Diseases
Respiratory conditions are broadly classified based on airflow limitation:
- Obstructive diseases (like Asthma, Chronic Bronchitis, Emphysema) primarily affect airflow, often leading to increased lung volumes due to air trapping.
- Restrictive diseases (like Pulmonary Fibrosis) primarily affect lung volumes, restricting the ability to inhale fully.
Impact on Total Lung Capacity (TLC)
Let's analyze the effect of each condition on TLC:
- Asthma: Primarily obstructive. TLC is often normal or increased due to air trapping during exacerbations.
- Chronic bronchitis: Obstructive. TLC is typically normal or increased.
- Emphysema: Obstructive. Characterized by alveolar destruction, leading to increased lung compliance and significant air trapping, thus increasing TLC.
- Pulmonary fibrosis: Restrictive. Involves scarring and stiffening of lung tissue, which reduces the lungs' ability to expand. This directly leads to a decrease in TLC.
Therefore, Pulmonary fibrosis is the condition among the options that characteristically decreases Total Lung Capacity.
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Important Questions from COPD
- The distance walked in 6 minutes is an indirect measure of which of the following variables of the 'BODE Index' which is used to assess the prognosis in chronic obstructive pulmonary disease?
- The most common cause of chronic type II respiratory failure is:
- Which of the following are categorised under obstructive lung disease ?
1. Bronchial asthma
2. Bronchiectasis
3. Bronchiolitis
4. Pulmonary sarcoidosis
Select the correct answer using the code given below: - Risk factors for development of COPD include which of the following ?
1. Tobacco smoking
2. Recurrent infection
3. Coal dust exposure
4. High socio-economic status
Select the correct answer using the code given below: - A 65-year-old male smoker has been diagnosed with Chronic Obstructive Pulmonary Disease (COPD). On pulmonary function testing, the $FEV_1/FVC < 0.7$ and $FEV_1 = 42\%$ of predicted. The severity of airflow obstruction in this patient as per GOLD criteria is :
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