They say one ought to learn a new word (or phrase) every day. I did today, courtesy of Radio 4:

Compassion fatigue

Now I know what gets us in the end
The back aches, rounded shoulders slump, while 
The corners of mouths droop to the chin
And forget, completely, how to smile

Yet another shift has been too long
And the rain clouds have blackened our sky
We’re stressed and, frankly, too tired to care,
That’s when words from our sharpened tongues fly

But don’t fret – no need to say sorry
To patients when we’re not on the ball 
Because, now, the condition’s explained
It’s compassion fatigue, folks, that’s all!