Allow me to clarify. The amount released by a plant at night is not going to kill you. Not even close. I'm just saying, if you want a restful sleep, it's best to get as much oxygen into your body as possible, anything that deters that will probably make your sleep slightly less so (which is why I'm thinking of making my wife sleep in another room...
)
Here's an article that I found on the subject.
Feng Shui Use of Plants in the Bedroom - Good or Bad Feng Shui?