My 89 Year Old Father Had Surgery I Think He

My 89 year old father had surgery I think he had a intestine ripped and they had to remove part of his colon. He had the surgery 5 days ago and has breathing tubes. Doctors can not remove the tubes until he wakes up. His vital signs are very good however he is not waking up completely. He opens and closes his eyes and turns his head but has not completely awaken. How long does has it every taken a patient to completely wake up after this type of surgery?