General hospitals are difficult places for people with dementia, since they are overwhelmingly busy places (even for people without dementia!). Even given the shortage of time, nurses will find it in the long run pays off to just spend that bit of time to establish a relationship with the patient with dementia who may well feel overwhelmed and confused given they are in an unfamiliar environment. Acknowledging someone as a person and communicating that does not take a lot of time. Also, do not assume that everything the person says or does is nonsense. Try to observe and tune into the non-verbal cues to help you work WITH rather than AGAINST patient. Both the verbal and the non-verbal communication from the person can help you understand what they need and what they are trying to communicate.
It's hard to see in the current healthcare climate that hospitals can change very much in terms of environment. In the aged care field, there are suggestions that nursing homes keep people in place wherever possible so that they remain in a familiar environment (very important for people with dementia) and an environment that is more suited to their needs.
I totally recognise the difficulties for nurses who are working in frantic, dementia-unfriendly environments, but would recommend looking beyond medical texts about the physiology of dementia and turning to texts which give the philosophy of person-centred approaches to dementia and some very practical tips for being with a person with dementia.