Time is very important when an unconscious person is not breathing. Permanent brain damage begins after only 4 minutes without oxygen, and death can occur as soon as 4 to 6 minutes later.
No. Resuscitation after cardiac arrest longer than 4 to 6 minutes at normal body temperature typically results in irreversible brain injury, coma, or death. Therefore there is a popular belief that the brain “dies” after 4 to 6 minutes without oxygen.
A full recovery from severe anoxic or hypoxic brain injury is rare, but many patients with mild anoxic or hypoxic brain injuries are capable of making a full or partial recovery. Furthermore, symptoms and effects of the injury are dependent on the area(s) of the brain that was affected by the lack of oxygen.
By nine minutes, severe and irreversible brain damage is likely. After 10 minutes, the chances of survival are low. Even if a person is resuscitated, eight out of every 10 will be comatose and sustain some level of brain damage. Simply put, the longer the brain is deprived of oxygen, the worse the damage will be.
This leads to asphyxiation ( death from lack of oxygen ) without the painful and traumatic feeling of suffocation (the hypercapnic alarm response, which in humans arises mostly from carbon dioxide levels rising), or the side effects of poisoning.
Blood circulation can be stopped in the entire body below the heart for at least 30 minutes, with injury to the spinal cord being a limiting factor. Detached limbs may be successfully reattached after 6 hours of no blood circulation at warm temperatures. Bone, tendon, and skin can survive as long as 8 to 12 hours.
Brain death (also known as brain stem death ) is when a person on an artificial life support machine no longer has any brain functions. A person who’s brain dead is legally confirmed as dead. They have no chance of recovery because their body is unable to survive without artificial life support.
Now UBC researchers have evidence that some people may still be able to hear while in an unresponsive state at the end of their life. This research, published recently in Scientific Reports, is the first to investigate hearing in humans when they are close to death.
Does an individual feel any pain or suffer after brain death is declared? No. When someone is dead, there is no feeling of pain or suffering.
It is possible for the brain to heal itself, with new brain cells growing to replace damaged ones, but much of the ‘recovery’ we experience is actually due to the brain ‘re-wiring’ itself and finding new pathways to bypass recently-broken connections.
Symptoms usually fall into four categories:
|Thinking/ Remembering||Physical||Emotional/ Mood|
|Difficulty thinking clearly||Headache Fuzzy or blurry vision||Irritability|
|Feeling slowed down||Nausea or vomiting (early on) Dizziness||Sadness|
|Difficulty concentrating||Sensitivity to noise or light Balance problems||More emotional|
Some conditions are easily treated with medication and therapy. For example, millions of people with mental disorders live perfectly normal lives. Other disorders, like neurodegenerative diseases and some traumatic brain injuries, have no cure.
A person who is brain dead is dead, with no chance of revival. Coma: A state of profound unresponsiveness as a result of severe illness or brain injury. Patients in a coma do not open their eyes or speak, and they do not exhibit purposeful behaviors. Some patients need ventilators while others do not.
For most people, it’s safe to hold your breath for a minute or two. Doing so for too much longer can decrease oxygen flow to the brain, causing fainting, seizures and brain damage. In the heart, a lack of oxygen can cause abnormalities of rhythm and affect the pumping action of the heart.