My 61 yr old father went into a coma on Monday due to Sepsis. Is there hope for a full recovery?

My 61 yr old father had a quadruple bypass and valve replacement in late December, and on Saturday he came in for an out patient procedure to remove the liquid in his lungs. However, they discovered he had a fever, so they admitted him and kept him for observation. On Sun they removed the liquid, and they gave him a transfusion due to being low and anemic on Mon 2/7. Within a few hours he went into some sort of shock. They rushed him into ICU and they performed CPR 2 times. They had difficulty stabilizing him, and they put him on full life support. His Dr said he probably wouldn't make it through the night but by some miracle and his will to survive he is still with us. He is completely off the heart pump but is still on the breathing machine (his breathing has significantly improved, so they plan to wean him off the ventilator). They discovered that the blood infection was due to an infection from his valve replacement surgery. He was diagnosed with Sepsis. Dr say he is fighting the infection, but is still in a comatose state. His nurse said his pulse was low but not stopped when they did CPR. The neurologist requested a CAT scan, and there were not signs of stroke or clots in his brain. However, he is still unconscious. He opens and closes his eyes and makes facial expressions as if he is in pain, bites down on breathing tube, and pupils are reactive, but does not obey commands. He also reacts to stimuli on his feet if tickled. In Nov when he had his heart attack they did not expect him to make it and just the same with his open heart. His will to survive has continued to prove everyone wrong. He is a fighter! My question to you: is it unreasonable to expect him to recover and come back to us? If so will he be normal? Thank you.