We know vamps can take air in so they can speak, but it dawned on me, can they produce oxygen?

Good vampire physiology question.

Did you mean can they produce carbon dioxide?  They take in air to speak, but I'm sure that they exhale the same air.  It probably does go into the blood stream from the lungs since their hearts don't beat and circulate their blood.  Humans need the oxygen for their blood, and it comes out as carbon dioxide after it's processed by the body.  So, if their is no circulation, then there probably isn't any carbon dioxide.

Of course, if vamps' hearts don't beat, and their blood doesn't circulate, then that wouldn't explain how male vamps get erections.  And we know that they must, or Buffy wouldn't have been able to have so much fun with Spike. So, Spike's gotta have some kind of blood flow in the erection direction...

Is it getting hot in here?

Fan yourself, Immortal.  Vampire blood could circulate the way your lymph system does, by body movement.  Spike's a twitchy guy, and he's even more twitchy when Buffy is around, so maybe that explains his abilities in the romance department.

Mmm, yes, it's hot in here,lol.

* put's on thinking cap* Yes, I mean Co2. I was just thinking if Buffy ever needed CPR would it be plausible for Spike to do such an act. But then we get into the whole vamp biology, and I'm thinking if they can eat food, and we know it has to come out some kinda of way same with drink, then maybe they can produce co2. Not as much as humans but maybe a little due to the blood flow that they have to have. Cause I really can't see a demon annimating the body without it having some minor spark of life.

Actually, Spike doing CPR should be even more effective than a human doing it. If his body doesn't do anything to the air he takes in, that air will contain the same amount of oxygen as the stuff that's swirling around; whereas the air a human exhales will contain less oxygen and more carbon dioxide than before. So if a vampire's breathing affects the air the same way a human's does, then the effectiveness of his CPR will be the same too - if on the other hand the air comes out just like it went in, then he will breathe MORE oxygen into you than a human would.

So no matter what happenes to the air, CPR will work just fine.

Thanks Dia. I'm locking this tid bit away for later use. :)

It bugged me when Angel said vampires can't breathe. There was no logic in that.