Escape Room

I am creating an escape room experience for trauma education and I was wondering if anyone has done this before and has any suggestions for successful puzzles. I have several puzzles already that generate a number or alpha code which will be used as a combo for a lock. For example, I have a photo of a trauma room and want them to pick the 4 things that are missing from the room. There will be a word bank of options. They will pick the correct items and put them in alphabetical order; the first letter of each word will be the combo for the lock. Like if the four things that were missing were Airway Cart, Monitor, Suction, Crash cart- the code for the lock would be ACMS.  This lock will open a cart or lockbox which will have the next clue. I am using this same kind of thing a few times, at least once with an number code. 

My issue is that I don't want spend a lot of time on intricate puzzles that have no bearing on the actual scenario or contribute to the learning itself. Decoding ciphers etc may be too time consuming. 

Any suggestions are appreciated! Thanks!