A couple weeks ago, my cousin was injured in a car accident. Trauma to the head and other injuries. My aunt emailed this morning and said
Hi, I had gone through your question and understand your concerns. If your cousin is diagnosed with brain death (there are examinations that determine it, EEG, cerebral and brain stem reflexes absent, etc.) then his heart can beat for an indefinite time if there is medical support, if no heart will stop soon. The time that human brain resists without oxygen is 3 to 5 minutes, beyond this time (without blood and oxygen) happens brain death and if the diagnosis is correct there is nothing to do to help him. Sorry I have to say this. Hope this answers your question. If you have additional questions or follow-up questions then please do not hesitate in writing to us. I will be happy to answer your questions.