In order to amputate my right ANYTHING, you'd first have to provide me with something that will allow me to survive the next few minutes of probably and extreme blood-loss. Otherwise, my arm will be sacrificed for nothing. You should never sacrifice something if you can't gain the thing you sacrificed it for. In this case, if your life is even more forfeit because you couldn't stop the bleeding, then it's a desperate act that gambled and lost. And as for me, I don't know if I could unless you really got me in a bind like Ash from the Evil Dead movies, where his own body part is otherwise trying to kill him.