Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which of the following is an abnormal result seen in COPD?

1. Increased FEV1

2. FEV1/FVC ratio below 0.7

3. Normal oxygen saturation

4. Normal lung sounds

The correct answer is: FEV1/FVC ratio below 0.7

In Chronic Obstructive Pulmonary Disease (COPD), an abnormal result characteristic of the condition is the FEV1/FVC ratio being below 0.7. This ratio compares the volume of air a person can forcibly exhale in one second (FEV1) to the total volume of air exhaled (FVC) and is crucial for diagnosing obstructive conditions. In COPD, which is characterized by airflow obstruction, this ratio is reduced due to a greater reduction in FEV1 compared to FVC. Hence, a ratio lower than 0.7 indicates that the patient has significant airflow limitation, which is a hallmark of COPD. Other findings associated with COPD typically include a decreased FEV1 rather than an increase, so the option related to increased FEV1 does not fit with the expected pathological changes. Normal oxygen saturation can occur in mild cases or during stable periods, but abnormal results, particularly during exacerbations, will often show low oxygen saturations. Lastly, normal lung sounds are generally not associated with COPD; instead, abnormal sounds like wheezing or decreased breath sounds are typically heard due to airway obstruction and hyperinflation. Thus, a low FEV1/FVC ratio effectively signifies respiratory impairment consistent with COPD.