Chrissa, this is actually good news that they are doing tests and keeping him under surveillance, because this time last week, you were telling us that he was planning to discharge himself! - good job then that he didn't, I am glad for you.
Drinking is so important - my dad had cirrhosis but nobody realised it (his was too much of drinking the wrong stuff tho) - but my mum was in hospital for a couple of weeks when she was in her nineties, and she too went very strange, almost "hospital fever" as someone said - I rang her up one day, she was very lucid, then told me that fishermen with nets had just arrived on the ward... very hard to handle if you don't realise what's happening, but it's not unusual as bednobs says. I wish you both well!