I asked:
> Such as what? I cannot imagine any such branch. Any medical
> care at all always involves the possibility of complications
> afterward, and such complications could certainly be life-
> threatening. 

R' Moshe Yehuda Gluck suggested:
> Podiatry? Dermatology? Cosmetic surgery?

That's exactly my point. In all of these, isn't there always a chance 
of post-operative infections, or sutures coming loose, or other sorts 
of emergencies which would require the doctor to examine and care for 
his patient? It might not be common, but my point is that there is no 
branch of medicine in which a physician can rest assured that he 
won't have to attend to a patient on Shabbos.

Surely we have an MD on the list who can offer some insight?

Akiva Miller