I don t have many details, but here is what I have. This is a 75 year old black male successfully underwent quadruple bypass surgery along with atrial fibrillation repair 10 days ago. He has kidney disease, however, is not on dialysis. At this point, he hasn t gained enough strength to leave the hospital permanently. He is very weak and doesn t have much of an appetite. My question is what are some possible reasons that could delay his recovery up to this point to where he is unable to leave the hospital, immune issues?