A driver with COPD should not be certified if their ABG reveals which of the following?

The primary consideration for certifying a driver with Chronic Obstructive Pulmonary Disease (COPD) lies in ensuring they have adequate oxygenation. In this context, arterial blood gas (ABG) levels, specifically the partial pressure of oxygen (PaO2), are critical indicators of a person's oxygen status.

A PaO2 reading below 65 mmHg is generally problematic, especially for individuals with COPD, as it signifies hypoxemia. This condition implies that the driver may not have sufficient oxygen levels to support safe operation of a commercial vehicle.

The option stating a PaO2 of 64 at an altitude below 5,000 feet indicates a concerning level of oxygenation. Since this reading falls below the threshold of 65 mmHg, it indicates the driver is at risk of inadequate oxygen delivery to vital organs, which could lead to impaired cognitive function, decreased alertness, and ultimately unsafe driving conditions.

In contrast, the other options present PaO2 levels that are either above the critical level or considered acceptable given the altitude. For instance, a PaO2 of 70 at an altitude below 5,000 feet and the other selections show values that, while low, do not fall below the critical threshold at varying altitudes