Which hypoxia type results from reduction in total cardiac output or pooling of blood?

Which hypoxia type results from reduction in total cardiac output or pooling of blood?

• A. Stagnant hypoxia
• B. Hypoxic hypoxia
• C. Histotoxic hypoxia
• D. Anemic hypoxia

Answer: (A)

The key idea is that oxygen delivery to tissues depends on blood flow as much as on how much oxygen is carried in the blood. When cardiac output is reduced or blood pools in the venous system, tissues don’t receive enough oxygen even though the blood may be adequately oxygenated. This is stagnation hypoxia, also called circulatory hypoxia, because the bottleneck is delivery due to impaired circulation rather than a lack of oxygen in the blood or the body's ability to use it. In contrast, other types involve the oxygen content or utilization: hypoxic hypoxia is low arterial O2 tension, anemic hypoxia is reduced O2 carrying capacity, and histotoxic hypoxia is cells unable to use O2 due to toxins.

The key idea is that oxygen delivery to tissues depends on blood flow as much as on how much oxygen is carried in the blood. When cardiac output is reduced or blood pools in the venous system, tissues don’t receive enough oxygen even though the blood may be adequately oxygenated. This is stagnation hypoxia, also called circulatory hypoxia, because the bottleneck is delivery due to impaired circulation rather than a lack of oxygen in the blood or the body's ability to use it. In contrast, other types involve the oxygen content or utilization: hypoxic hypoxia is low arterial O2 tension, anemic hypoxia is reduced O2 carrying capacity, and histotoxic hypoxia is cells unable to use O2 due to toxins.