If a driver with COPD shows obvious difficulty breathing at rest, what test is required?

In a scenario where a driver with Chronic Obstructive Pulmonary Disease (COPD) demonstrates significant difficulty breathing while at rest, the most appropriate test required is Pulmonary Function Tests (PFTs). PFTs are specifically designed to evaluate lung function by measuring various aspects of pulmonary health, including airflow, lung volumes, and gas exchange efficiency. These tests can provide critical insights into the severity of the COPD and help determine the driver's ability to safely operate a vehicle.

The results from PFTs guide medical examiners in assessing the driver's respiratory capacity and overall fitness for driving. This evaluation is crucial for ensuring that a driver with compromised lung function is capable of handling the physical demands of driving, which can be affected by inadequate oxygenation and breathlessness.

While other tests like a Chest X-ray or Blood Gas Analysis can provide additional information about the structural aspects of the lungs or specifics about oxygenation and carbon dioxide levels, respectively, PFTs directly assess how well the lungs are functioning in terms of airflow and overall respiratory health, thereby making them the most relevant initial test in this situation. An Electrocardiogram (ECG) would be of lesser priority as it primarily assesses heart function rather than lung capacity, which is the key issue here