PS: I do not know if this will help you. I do not even know if you still care enough about wife to try to help her get a better grip on realities of safe BDSM. Or maybe you are at the place of just protecting yourself and the kids.
It is a sad situation.
Subspace description of hormone cascade
Possible sub frenzy symptons
There's ethics to BDSM -- and I don't know your relationship to the dom or if the dom even is a responsible one. But maybe they are not aware of the probs at home?