During Chapter 8, you must not shoot any of your weapons to get the "Item Management" trophy. You can equip your weapons, but you are not allowed to use them. The only tough part is at the very beginning where there are several enemies roaming the area. You need to use a crank to open a gate, but there are two enemies in front of it. You have to lure them away to the other end of the cave. Just let them see you, and slowly walk away (not too fast or they will lose you and return to their original positions). Once you have lured them away, run back to the gate as quickly as possible and open it. The rest of the chapter is easy. Simply run past all the enemies to complete the chapter in a few minutes.