What to expect from 68 year old man diagnosed with mild vascular dementia in 2009? He had open heart surgery in 2007 with a 3x by-pass and sophisticated tests show vascular issues. Now in 2016 he is becoming very irritated and grouchy. He is on a CPAP mask at night and 24 hour oxygen but last year refuses to use the oxygen during the day unless driving. We do not have most meals together nor much conversation. He sleeps many hours a day.