National Registry of Certified Medical Examiners (NRCME) DOT Practice Exam

What is the significance of an FEV1 less than 65% in a driver with COPD?

1. It indicates a need for immediate disqualification

2. It requires additional pulmonary testing

3. It is irrelevant for certification

4. It allows for certification under any circumstances

The correct answer is: It requires additional pulmonary testing

An FEV1 (forced expiratory volume in one second) of less than 65% in a driver diagnosed with chronic obstructive pulmonary disease (COPD) is significant because it signals a potential compromise in lung function that could affect the driver's ability to operate a vehicle safely. In the context of medical certification for commercial drivers, this FEV1 level suggests that the driver may be at increased risk of experiencing breathing difficulties, which could impair their reaction time and overall capacity to respond to driving demands. As such, further evaluation through additional pulmonary testing is warranted to fully assess the severity of the lung impairment and determine the appropriate course of action for certification. This may include tests that measure diffusion capacity or other specific metrics of respiratory function. The results of these additional tests can provide insights into the impact of the COPD on driving safety and help in making an informed decision about certification eligibility. The other options do not align with standard practices for handling cases of significant pulmonary impairment. Immediate disqualification is not automatically warranted based solely on FEV1 levels; rather, further assessment is critical. The assertion that an FEV1 of less than 65% is irrelevant for certification is incorrect because it directly relates to the individual's fitness to drive. Finally, the option stating that