No one should be disfellowshipped for trying to save their life.
But for the record, non-blood medical management is the safest form of treatment if the option is available to you. In part, I am speaking from my own involvement (I played a very small part) in changing health policy throughout a large part of UK. Studies brought to the attention of the health services showed that in relation to certain kinds of cancer, if you did not have a blood transfusion the chances of a better outcome for you were much improved. Moreover, it was cheaper. So much so the military were interested.
The evidence was so overwhelming that clinicians and judiciary approved the change in policy very quickly. If I remember correctly the policy change was to use cell salvage rather than give a transfusion.
Non JW family members have undergone surgery without blood and have come through well. GP friends who at one time felt blood was necessary have changed their minds and would opt to not have a blood transfusion if possible.
But in my case I got df'd for sticking to the words of the prophet Daniel. But there are plenty of things they'll turn a blind eye to when it suits them as Sir82 said.