tell me more

[lang]

I am in the fire service for a couple of years now and have been using positive pressure SCBA quite a number of years. While browsing through the different topics I came across the following comment -

quote:
SCBA's: They were Demand Style, so they did not Force Air into your Lungs when you were Unconscious..

Now I would really like to know more about a positive pressure SCBA set that is delivering enough pressure through the demand valve to actually force air into the lungs of an unconscious person.

Comments????????????

[quint1driver]

I don't think thats right.
1. Does unconscious mean not breathing?
2. And even if it did, there isn't enough pressure to do that. PP only keeps contaminants from entering the mask through a poor seal by increasing the mask pressure to slightly more than atmosphere.
At least thats what I think.

[lang]

quint1driver I agree with you, there is no ways that a PP SCBA can force air into someone's lungs as the positive pressure for most SCBAs are in the vacinity of around 5 to 7 mbar above atmospheric pressure. If the person is breathing but unconscious he would be able to get air from a demand valve set as well.

[postal79]

positive pressure means exactly that, positive pressure like quint said it is slightly higher pressure than you or i walk around with everyday outside, so that (again like quint said) if you dont have a good seal and you have an opening air will rush out of the mask so that contaminants cant come in or at least not as much

[570eck]

I agree with the above posts. I believe what the person you were quoting was thinking about might have been postive pressure "vents?" used by ems. Which do have the ability to force air into lungs thru an unobstructed airway. But postive pressure scba can definitly not, how would you exhale?