In obstructive lung disease, a decreased FEV1 is typically associated with which finding?

• A. Increased FVC
• B. Normal FVC
• C. Increased peak flow rates
• D. Decreased peak flow rates

Answer: (D)

In obstructive lung disease, a decreased FEV1 is typically associated with decreased peak flow rates. This relationship stems from the nature of obstructive conditions, such as asthma or chronic obstructive pulmonary disease (COPD), where airflow limitation occurs primarily during expiration due to narrowed airways.

When a patient with obstructive lung disease attempts to exhale forcefully, the maximum volume of air that can be forcefully exhaled in one second (FEV1) is reduced because the obstruction prevents a free flow of air. As a result, peak flow rates, which measure how quickly air can be expelled from the lungs during forced expiration, are also decreased. This indicates that the obstructive process is significant enough to impede both FEV1 and peak flow measurements.

In contrast, other options would not be accurate reflections of the respiratory mechanics in obstructive lung disease. For instance, an increased FVC might suggest that air trapping is occurring, but it does not typically result in an increased FVC. Similarly, a normal FVC does not align with the understanding of obstructive diseases, where FVC may remain normal or be slightly decreased, and increased peak flow rates are not consistent with the pathology seen in obstructive lung conditions. Thus, D