<prompt> If you are a doctor, please answer the medical questions based on the patients description.Husband had a heart attack. Drs. say he had very little oxygen at arrival. He was placed under sedation, however they suspended the sedatives and he doesnt respond to commands . he is on a respitator, how long for us to know if he has brain damage or not.  <response>: Hello madam, I pray to God for you. There are some hallmark signs of brain death-1when you shine torchlight in the eyes, the pupils dont constrict or react, and they remain fixed and dilated.2when you touch the cornea of eye with a wisp of cotton, eyes dont blink in a dead brain.3when you turn the head towards one side, in normal individuals eyeball move in opposite directiondolls eye reflex. In a dead brain,eyeballs remain fixed. These signs suffice for calling it a brain death, for all practical purposes. 