When all else fails, turn on the water works.
My daughter was very lucky that early on in her career she spent 5 years as an ambulance-driving EMT. This experience steeled her constitution for all the gore and heartache. Then, when she got her BSN and CEN to work as an emergency room nurse, she knew how to handle these kinds of things.
There was one time when she was working in a downtown Richmond ER that 2 kids had been shot; they were riding ponies at a birthday party while in a nearby basketball court some punks shot each other up in an argument. Stray bullets made it to where the kids were. The 11-year old brother died on the way to the hospital. My daughter held the hand of the surviving sister and comforted the 8-year old while they removed the bullet from her chest.
I asked her how she managed. She said “you learn to be caring, professional and helpful, but you’ll go nuts if you let it get to you.”