Which type of hypoxia is caused by reduction of PO2 in the lungs, resulting in inadequate oxygen delivery to arterial blood?

Which type of hypoxia is caused by reduction of PO2 in the lungs, resulting in inadequate oxygen delivery to arterial blood?

• A. Hypoxic Hypoxia
• B. Hypemic Hypoxia
• C. Stagnant Hypoxia
• D. Histotoxic Hypoxia

Answer: (A)

Hypoxic hypoxia occurs when the PO2 in the lungs is reduced, so less oxygen diffuses into the blood. This lowers arterial PO2 and hemoglobin saturation, causing a decrease in arterial oxygen content and, consequently, insufficient oxygen delivery to tissues. This situation is typical with low inspired oxygen or impaired alveolar gas exchange, such as at high altitude or with hypoventilation. The other types involve problems with oxygen carrying capacity (hypemic), oxygen transport despite normal arterial oxygen (stagnant), or cellular inability to use oxygen (histotoxic), which is why the reduction in alveolar PO2 points to hypoxic hypoxia as the correct explanation.

Hypoxic hypoxia occurs when the PO2 in the lungs is reduced, so less oxygen diffuses into the blood. This lowers arterial PO2 and hemoglobin saturation, causing a decrease in arterial oxygen content and, consequently, insufficient oxygen delivery to tissues. This situation is typical with low inspired oxygen or impaired alveolar gas exchange, such as at high altitude or with hypoventilation. The other types involve problems with oxygen carrying capacity (hypemic), oxygen transport despite normal arterial oxygen (stagnant), or cellular inability to use oxygen (histotoxic), which is why the reduction in alveolar PO2 points to hypoxic hypoxia as the correct explanation.