My dad is 79 yrs old, and has a defibrillator. One week agao, he had a four hour complicated surgery for removal of a gangrene gall bladder . He has no energy, not eating and is not moving or has use of his legs. Is this normal given the type or surgery and his age and heart. Should we consider a rehab center to asist him in getting him back on his feet. ( He was active before the surgery). Thank you.