If it was OHS, it isn't exactly "normal" to be in the ICU for 4 days, but, it isn't abnormal, either. It is, on the other hand, not unusual for a heart surgery patient to require blood. In any case, talk to his surgeon to get an update on what's going on, what's slowing his recovery, and about anti-nausea medication. He probably can't ingest anything, but there are some patches that can be placed behind a patient's ear, that can help curb nausea.
If it was bypass surgery, it doesn't sound normal in my experience. but it depends on what's going on. everyone is different. talk to his doctor.