DOT Certification Practice Exam

What is the minimum accepted FEV1?

1. 55% of predicted

2. 60% of predicted

3. 65% of predicted

4. 70% of predicted

The correct answer is: 65% of predicted

The minimum accepted FEV1, or Forced Expiratory Volume in one second, is generally considered to be around 65% of the predicted value for patients to be classified as having no significant obstruction or impairment in lung function. This percentage serves as a key threshold in respiratory medicine, particularly in the context of chronic respiratory diseases such as asthma and COPD, where maintaining lung function is critical for overall health and quality of life. When interpreting FEV1 results, values lower than this threshold may indicate varying degrees of obstruction or impairment. It's important to understand that 65% is a clinically relevant marker that guides healthcare professionals in diagnosing and managing respiratory conditions. Using this benchmark helps in assessing the severity of lung disease and making informed decisions about treatment options. The options that suggest percentages lower than 65% may lead to a misclassification of a patient's lung function status. Thus, the distinction of 65% as the minimum accepted value reflects an established understanding in clinical practice regarding the assessment of pulmonary function.