Yes Shabbos is a challenge faced by many physicians, more so than other professions.
however there are a wide variety of approaches to how this is handled.
Partly depending on specialty
There are some who work (almost) every Shabbos there are others who have never had any call or done any melacha on Shabbos.
and there are many in between.
I am fairly certain this was mentioned already. and I dont really think think there is much to debate on this issue (as far as the metzius)