What Are The Chances Of Regaining Consciousness After Being Freezed Due To Breathing Problem?

Hi, I wonder if my brother will ever be conscious again. He is in a ventilator. He has lung infection. The doctors freeze his lungs and give him steriods. He had trouble breathing so they revived him. His other organs are working ok except he cannot breathe on his own. What are the chances that he will wake up. It s been 3 days now. Any answers will be appreciated. Thank you.