Since nothing matters if one is not alive, anything goes to save life.
I know that some will bring up instances of vows before God in Scripture, e.g. Jephthah, to kill someone. But in Christianity, such vows should never be made and would probably be invalid if made.
It would still be useful to know what kind of promises are being discussed. And if somebody’s actual life is in play, then by all means, go to someone with authority rather than a bunch of names on a BBS.
God Bless and ICXC NIKA