well it depends what type of nurse, a doctor nurse or hospital nurse, i think a hospital nurse would be hard to let 'people go' when they die, you see their family cry and stuff...
not killing the patient
The most challenging thing is surgery.
I always found the most challenging thing in photography was the next think I was going to photograph. What I had done was in the past and behind me, the future was always a challenge.
the most challenging thing is getting everything right! you get one thing but then another just slips away.
the most challenging thing i had expereinced in my life was when i got drunk it was not that easy because i wasa not prepared.
probably the babies dying would be the hardest part of that paticular job
Paper writing.
If you have your own practice, the most challenging thing would probably be dealing with the insurance companies because in today's world you will have to really jump on insurance companies when trying to get their payments. If you don't have your own practice, it would probably be very worried parents. :)
Leaving my boss breathing.
Pain is a very subjective thing, This would depend on the individual undergoing the procedure. and the skill or possibly luck of the surgeon doing the job.
The most challenging trail at Whistler Blackcomb is the Couloir Extreme. Another famously challenging trail is the Big Bang. The most challenging trails are these two.
Your doctor knows all about your history and would be aware of most of your risks. They would be the best start to being able to recommend a heart surgeon or specialist.
You think that the most challenging part of this unit will be?