What Happens To PO2 During Hypoventilation?

What Happens To PO2 During Hypoventilation? For example, a decrease in either PO2 of the atmospheric air (changes with altitude) or in alveolar ventilation (hypoventilation) will decrease the amount of fresh air entering the alveoli per unit time. Likewise, an increase in the rate of total body O2 consumption will decrease PO2 in the alveoli.