I am definitely on the side of "case by case". Having worked in ICU, step-down, cardiac, neonatal, and even peds, I have seen it all. I am definitely not in favor of unrestricted 24-hour open visitation; that leads to way too many people and way too many problems. Been there, seen that. In peds, one parent, grandparent, adult relative, or a sibling over 16 was expected to stay with the patient at all times. Occasionally this meant there was a party in the room, not always appreciated by the patient! Fortunately we could kick out non-relatives after 9 pm, which helped some. But in other hospitals where they had 24 hour open visitation, it could get pretty raw. Big urban ones are definitely the worst...and can be scary too. Inappropriate family members were the least of our problems. Thank goodness for security, although there were never enough of those sometimes. In smaller hospitals where the occasional "dignitary" is treated like royalty you can really have major problems if you have open visitation. I remember one prominent politician who was a patient in a smaller, but still urban hospital in our cardiac unit, whose family took *full* advantage of 24 hour open visitation even when it wasn't standard for everyone else, and demanded to be waited on even though he didn't. They frustrated attempts to get him up and moving, and when he crashed post-op, as open hearts often do, they were totally in the way, screaming and crying and carrying on. After they took him back to CVICU the charge nurse had to bar them for awhile until they settled down, and they went to management, but the man himself, when he got better, spoke up on the nurse's behalf (to his credit--that doesn't always happen!). I could tell a lot more stories, but I'll stop for now.
When my dad went to the hospital with pneumonia at 90, my brothers and I stayed with him. He was in PCU and was DNR/DNI, but otherwise was being treated pretty aggressively, which we later recognized as probably not the best course. He had dementia and CHF and we took shifts so there was always at least one of us with him. I'm a nurse and one of my brothers is an internist so we knew pretty much what was going on and could help the nurses as well as explain to the doctors, and we tried to stay out of the way as much as possible. I've been in the hospital with my kids and my mother as well and generally try to be of assistance because I know how things are on the other side. On balance, how I feel about 24 hour visitation is that the nurse needs to have the discretion to set parameters and say no without fear of reprisals from management, and that families/visitors need to be told what the rules are and that if they can't follow them, they are OUT, period.