We have used lots of different strategies. Our DS has had four heart surgeries and many stays in hospt - and he is only four.

We have had trouble with trauma in hospt before and have used the following;
# story books can be useful
# seeing child physcologist to get some help on the best thing to say to your child - BTW we never tell him to be brave, its like telling him to lie to us that it doesnt scare him
# asking for the play therapist to do a consult with us around distraction and self calming techniques that son can use
# having play therapist there for tests/procedures to assit us and our son (and the nurses!)
# talking with any regular nurses/professions about what the triggers are and how we want things done - we have very regular blood tests (weekly at the moment) which caused him so much distress that we had to really work hard to get anything done
# drugs, we actually had to use Midazolam (sedation) for our son each day for 10 days in hospt to be able to do procedures without increasing his trauma recently
# providing medical play options at home, we have a blank doll and canula, bandage, syringe, gas mask etc for DS to choose to act out procedures if he wants. It has been great to get him to tell us how dolly is feeling and what dolly needs us to do to help her etc.
# getting a Captain Starlight to meet us for appointments and procedures to provide fun and distraction. We only get them to meet us every second time or so now just to show DS that it is ok if Capt S isnt there too.
# repeating the same phrases each time; Mummy is here, not long now, nearly finished, good yelling (not trying to get him to hush and be brave)
# asking him what he needs us to do - he wants us to hold him on my lap and hide his eyes when the needles come etc.

Wow, thats a long list isnt it?? Phew.

Hope that helps, happy to answer any more qu's if you need.

Rachel