I Have A Cupple Questions,my Brother Is In Hospital And

I have a cupple questions,my brother is in hospital and I'm curious about some things that worry me...he just had surgery because he had a bone replacement on his head and everything went well and he now is in the ICU recovering going on 3rd day but hes given the small dose for pain of Tylenol and it's his third day and since he can't talk or react I'm his voice...my question is he supposed to have that low of pain meds cause I've had surgery myself and I even remember crying and being in a lot of pain and Tylenol wasn't strong enough...