Stagnant hypoxia is caused by an inadequate supply of blood to the brain and can be caused by which factor?

Stagnant hypoxia is caused by an inadequate supply of blood to the brain and can be caused by which factor?

• A. G-forces
• B. Oxygen toxicity
• C. Humidity
• D. High CO2 levels

Answer: (A)

Stagnant hypoxia happens when the brain and tissues don’t get enough oxygen because blood flow to them is reduced, not because the oxygen content of the blood is too low. In flight, high acceleration (G-forces) pushes blood away from the brain toward the lower body, lowering cerebral perfusion. Even with normal oxygen levels in the blood, the brain can be undersupplied if blood flow is compromised, leading to symptoms like lightheadedness or blackout. That’s why G-forces are a classic trigger for stagnant hypoxia. Oxygen toxicity involves too much oxygen, humidity doesn’t directly affect oxygen transport, and high CO2 levels affect breathing control rather than causing stagnation from reduced blood flow. Therefore, the factor that can cause stagnant hypoxia is G-forces.

Stagnant hypoxia happens when the brain and tissues don’t get enough oxygen because blood flow to them is reduced, not because the oxygen content of the blood is too low. In flight, high acceleration (G-forces) pushes blood away from the brain toward the lower body, lowering cerebral perfusion. Even with normal oxygen levels in the blood, the brain can be undersupplied if blood flow is compromised, leading to symptoms like lightheadedness or blackout. That’s why G-forces are a classic trigger for stagnant hypoxia. Oxygen toxicity involves too much oxygen, humidity doesn’t directly affect oxygen transport, and high CO2 levels affect breathing control rather than causing stagnation from reduced blood flow. Therefore, the factor that can cause stagnant hypoxia is G-forces.