Son won't fall asleep without a pacifier. If there are no nipples in h…

Son won't fall asleep without a pacifier. If there are no nipples in hand, it's chaos - he won't sleep. As soon as he falls asleep, I take it out, and he searches for her with his hands through sleep and wakes up if I don't give him back. We're on IV. Before bed when I give him a bottle of formula, he doesn't fall asleep until he gets the pacifier. How can you stop this? I'm afraid that it will be harder to stop later.