A pilot experiencing the effects of hyperventilation should be able to restore the proper carbon dioxide level in the body by which methods?

• A. Slowing the breathing rate, breathing into a paper bag, or talking aloud
• B. Holding the breath until the urge to breathe passes
• C. Increasing the breathing rate rapidly
• D. Drinking carbonated beverages

Answer: (A)

When someone hyperventilates, they blow off CO2 faster than the body produces it, lowering the CO2 level in the blood. That drop causes symptoms like dizziness, tingling, and lightheadedness because the low CO2 narrows cerebral blood vessels and reduces blood flow to the brain. To restore the proper CO2 level, you want to rebreathe some of the exhaled air and slow the breathing down so CO2 can build back up to normal.

Breathing into a paper bag helps because the exhaled air is inhaled again, increasing the CO2 in the fresh breath and raising the blood CO2 more quickly. Slowing the breathing rate reduces ongoing CO2 loss and allows levels to rise back toward normal. Talking aloud can also help by breaking the rapid, shallow breathing pattern and promoting a steadier, slower breathing cadence, which supports CO2 restoration.

Other options don’t fit as well. Rapidly increasing the breathing rate would push CO2 levels even lower and worsen symptoms. Holding the breath can be temporary, but it’s not a reliable or safe long-term fix and can lead to faintness. Drinking carbonated beverages won’t promptly or reliably correct CO2 levels in the blood.