Whta causes hyperventalation and why does breathing into a bag help correct it?

Factual Questions
1

Last night, our marching band’s performance at a football game was rained out, though the game went on. For a while, we had to keep our students on the un-air-conditioned school buses while we worked out what to do next. Since it was raining quite hard, the students kept the windows closed. However, since the weather was still quite warm and the buses were crowded, the temperature and humidity rose sharply.

One 14-year-old female student began to hyperventilate. I took her outside into the cool rain and fresh air and worked on getting her calmed down. I was mostly unsuccessful until a had her place a bag over her face and nose and breath into it / from it. This got almost immediate results. Within about five minutes, the girl’s breathing returned to normal, her color came back, and she was much more herself. All signs of the problem went away within about ten minutes.

The atmosphere inside the school bus was extremely uncomfortable. What about that atmosphere may have triggered hyperventilating in an otherwise healthy girl while other students (some of whom do have health issues) were unaffected? Why does breathing into a bag help?

(Just a few minutes later, we had a more acceptable shelter for the students. Even without the girl’s brief attack, we knew we had an unsustainable situation and were rapidly working toward a solution. We were at a school we hadn’t visited before and we didn’t know the local band director and administrators. Once we got that worked out, all was better.)

2

Hyperventilation is breathing too fast, and is usually caused by panic or anxiety, although it can be a response to elevated carbon dioxide. It’s a problem because it reduces CO[SUB]2[/SUB] below the normal level, which causes an increase in blood pH and all manner of associated symptoms. Going outside just makes it worse; rebreathing air from a bag raises CO[SUB]2[/SUB] and restores normal functioning.

3

Not recommended any more. Some say it is dangerous, and some studies say it is no better than breathing through an open tube.

Cite

The danger lies in misdiagnosing an asthma attack or heart attack as hyperventilation, and thereby depriving the person of oxygen when they need it most.