I think there can be two things that go through the minds of
such nurses :
Either :
- they are pro-euthanasia and strongly believe that due to the low
or no quality of life and the constant suffering the patients go
through, they'll find release and peace in death;
OR :
- they have some underlying psychological issues and are playing
God. 
I'm not making excuses for such action. Just wondering what in the
world could these nurses be thinking! 