Is Recovery Possible Following Difficulty In Brain Function After Drowning?

my husband drown in a cold river in oregon a year ago. he was under water for two hours, which was documented by his watch and the emergency room doctors. he survived but is now having issues with brain function, eye movement, and memory. he is on oxygen because of later pneumonia. does he have a chance of recovery? the doctors say they have no way of knowing if any of this is permanent and are amazed that he is alive.