Certified Respiratory Therapist Practice Exam

Which pulmonary function testing procedure is recommended to evaluate and follow interstitial lung disease?

1. Forced Expiratory Volume

2. Diffusing Capacity (DLCO)

3. Peak Flow Measurement

4. Static Lung Volume Measurement

The correct answer is: Diffusing Capacity (DLCO)

The recommended pulmonary function testing procedure to evaluate and follow interstitial lung disease is diffusing capacity (DLCO). This test measures how well oxygen and other gases diffuse from the lungs into the blood. In interstitial lung diseases, the alveolar wall thickening and the loss of surface area can significantly affect gas exchange, making the DLCO test particularly relevant. Monitoring DLCO levels can provide insights into the progression of the disease, as a decrease in DLCO often correlates with worsening interstitial lung disease. This is vital for both the diagnosis and management of patients with these conditions, helping healthcare providers assess the severity of lung involvement and guide therapeutic interventions. Other pulmonary function tests, such as forced expiratory volume, peak flow measurement, and static lung volume measurement, do not specifically assess the diffusing capacity of the lungs or the impact of interstitial lung disease on gas exchange, making them less suitable for this purpose.