Field Internship Student Data Acquisition Project. (FISDAP) Airway Practice Exam

What stage of COPD activates the hypoxic drive?

1. Early stage

2. Moderate stage

3. Late stage

4. Terminal stage

The correct answer is: Late stage

In the context of Chronic Obstructive Pulmonary Disease (COPD), the hypoxic drive refers to the body's response to low oxygen levels in the blood as a primary stimulus for breathing, rather than the typical carbon dioxide (CO2) levels. This adaptation tends to occur in the later stages of COPD due to the progressive nature of the disease, which includes substantial lung damage and reduced gas exchange capacity. As the disease advances to the late stage, individuals often develop significant air trapping and decreased lung volume, leading to lower oxygen saturation levels. In these cases, the body begins to rely more on hypoxia as a trigger for respiratory drive. This shift is particularly important because prior to reaching this stage, the body primarily responds to elevated CO2 levels. Thus, during the late stage of COPD, patients may not respond as effectively to hypercapnia (high CO2 levels) because their respiratory center becomes less sensitive to it over time. Consequently, individuals might already have elevated CO2 levels, and the hypoxia becomes the dominating factor that stimulates breathing. This physiological change underscores why the late stage of COPD is when the hypoxic drive becomes significantly activated and is a crucial point for managing patients in respiratory distress.