Brain death (also known as
But without a ventilator to keep blood and oxygen moving, this beating would stop very quickly, usually in less than an hour, Greene-Chandos said. With just a ventilator, some biological processes — including kidney and gastric functions — can continue for about a week, Greene-Chandos said.
Occasionally, a person's limbs or torso (the upper part of the body) may move, even after brain stem death has been diagnosed. These spinal reflex movements are generated by the spinal cord and don't involve the brain at all.
Brain death is often confused with other conditions that seem similar, such as coma and vegetative state. Brain death: Irreversible cessation of all functions of the entire brain, including the brain stem. A person who is brain dead is dead, with no chance of revival.
The three essential findings in brain death are coma, absence of brain stem reflexes, and apnea. An evaluation for brain death should be considered in patients who have suffered a massive, irreversible brain injury of identifiable cause. A patient properly determined to be brain dead is legally and clinically dead.
Of the 38 patients, 15 had these motor movements. In all cases, the movements were seen in the first 24 hours after brain death diagnosis, and no movements were seen after 72 hours. Some of the movements occurred spontaneously; others were triggered by touch.
It is irreversible. Once brain tissue dies, there is nothing that can be done to heal it.
Agonal breathing or agonal gasps are the last reflexes of the dying brain. They are generally viewed as a sign of death, and can happen after the heart has stopped beating.
Variability in the diagnosis of brain death has the potential to lead to misdiagnosis. Even in the clearest circumstances, families may have difficulty accepting a diagnosis of brain death when they see their loved one's heart still beating and feel their body warm to the touch.
“Our data shows that a dying brain can respond to sound, even in an unconscious state, up to the last hours of life.”
As the blood pools, patches appear on the skin within 30 minutes of death. About two to four hours postmortem, these patches join up, creating large dark purplish areas towards the bottom of the body and lightening the skin elsewhere. This may be less apparent on darker skin. This process is called livor mortis.
These movements were observed mainly within the first 24 hours after declaration of brain death and consisted of spontaneous jerks of the fingers, undulating toe flexion, triple flexion, unilateral facial myokymia, "Lazarus sign," upper limb pronation/extension reflex, and flexor plantar response.
In the hours before death, most people fade as the blood supply to their body declines further. They sleep a lot, their breathing becomes very irregular, and their skin becomes cool to the touch. Those who do not lose consciousness in the days before death usually do so in the hours before.
Pupils dilate
When people die, their bodies relax. This impacts your eyes just as much as the rest of your body. As soon as the muscles that control your eye movement relax, the pupils dilate. This happens over a progression of several hours after death.
Brain death is not the same as coma, because someone in a coma is unconscious but still alive. Brain death occurs when a critically ill patient dies sometime after being placed on life support. This situation can occur after, for example, a heart attack or stroke.
Choosing to remove life support usually means that the person will die within hours or days. The timing depends on what treatment is stopped. People tend to stop breathing and die soon after a ventilator shuts off, though some do start breathing again on their own.
Twenty-five percent of all unconscious patients can hear, understand, and emotionally respond to what is happening in their external environment. However, because of their medical condition, they are incapable of moving or communicating their awareness.
They won't normally respond to sound or pain, or be able to communicate or move voluntarily. Someone in a coma will also have very reduced basic reflexes such as coughing and swallowing. They may be able to breathe on their own, although some people require a machine to help them breathe.
Also, spontaneous motor activity (excluding spinal reflexes), shivering, seizures, and any response to painful stimuli must be absent. Because many other disorders can affect these functions, additional clinical evaluation is essential to establish brain death.
Often before death, people will lapse into an unconscious or coma-like state and become completely unresponsive. This is a very deep state of unconsciousness in which a person cannot be aroused, will not open their eyes, or will be unable to communicate or respond to touch.
The higher brain standard of death identifies key aspects of what makes us persons, and then identifies the death of the source of those aspects as the death of the person. The higher brain account thus functions by identifying our personal identity with the cerebral hemispheres in some way.
The UDDA in combination with the DDR assures patients, families, physicians, and other health professionals that a patient who is brain dead is in fact dead, making removal of organs for life-saving transplantation legally and ethically acceptable.
Brain dead patients look asleep, but they are not. They do not hear or feel anything, including pain. This is because the parts of the brain that feel, sense, and respond to the world no longer work. In addition, the brain can no longer tell the body to breathe.