Final answer:
In patients with COPD, the normal PaO2 can be lower than in healthy individuals.
Step-by-step explanation:
In patients with COPD, the normal PaO2 (partial pressure of oxygen in arterial blood) can be lower than in healthy individuals. This is because COPD leads to impaired lung function and reduced oxygen exchange in the alveoli. As a result, the PaO2 in COPD patients is generally below the normal range of 80-100 mm Hg.