But without brain function, the body eventually shuts down, unless there is medical intervention. Someone on a ventilator may appear to be breathing, but cannot breathe on their own. While the heart usually stops within 72 hours, it could continue beating for “a week or so,” Varelas said.
The heart continues to beat while the ventilator delivers oxygen to the lungs (the heart can initiate its own beating without nerve impulses from the brain) but, despite the beating heart and warm skin, the person is dead. Since the brain has stopped working, the person won't breathe if the ventilator is switched off.
Several years ago, the autopsy report of a totally brain-dead patient named TK who was kept on life support for nearly twenty years was published in the Journal of Child Neurology. He remains the individual kept on life support the longest after suffering total brain failure.
Brain death is legal death
It can be confusing to be told someone has brain death, because their life support machine will keep their heart beating and their chest will still rise and fall with every breath from the ventilator. But they will not ever regain consciousness or start breathing on their own again.
Recently, two cases of reversible “brain death” have been reported from academic tertiary hospitals (Joffe et al. 2009; Webb and Samuels 2011). In addition to the above-mentioned dramatic, spontaneous full recovery from “brain death,” there are also many well-documented cases of “brain-death” survivors.
The first organ system to “close down” is the digestive system. Digestion is a lot of work! In the last few weeks, there is really no need to process food to build new cells. That energy needs to go elsewhere.
Patients may be misdiagnosed as “brain dead” if their doctors fail to order the necessary tests to determine whether or not they are aware of their condition and unable to communicate. Individuals who have suffered severe brain injuries need to be accurately diagnosed to receive the best possible care and treatment.
When a patient dies, doctors stop treatment and instead focus on organ viability. The body is kept on life-support machinery if the patient was a registered organ donor or while the family makes decisions about organ donation.
If there's no sign of brain activity, doctors sometimes test again 6 to 24 hours later to make sure the person again shows no response. After testing twice with no response, doctors know that the person is brain dead.
There is no rule about how long a person can stay on life support. People getting life support may continue to use it until they either recover or their condition worsens. In some cases, it's possible to recover after days or weeks of life support, and the person can stop the treatments.
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.
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.
One blood flow study was considered to have yielded a false-negative result. No patient recovered or survived. Conclusions: The clinical diagnosis of brain death is highly reliable when made by experienced examiners using established criteria. In this study, the accuracy was 100%.
A variety of reflex movements have been reported in patients with brain death, such as plantar responses, muscle stretch reflexes, abdominal reflexes, and finger jerks (2). Because the aforementioned reflexes are spinal reflexes, the existence of such reflex movements does not preclude the diagnosis of brain death.
They Know They're Dying
Dying is a natural process that the body has to work at. Just as a woman in labor knows a baby is coming, a dying person may instinctively know death is near. Even if your loved one doesn't discuss their death, they most likely know it is coming.
This stage is also one of reflection. The dying person often thinks back over their life and revisits old memories.4 They might also be going over the things they regret.
Your loved one may become restless and pull on bed linens or clothing, hallucinate, or even try to get out of bed, due to less oxygen reaching their brain. Repetitive, restless movements may also indicate something is unresolved or unfinished in the person's mind.
There are a number of criteria for diagnosing brain death.
a person must be unconscious and fail to respond to outside stimulation. a person's heartbeat and breathing can only be maintained using a ventilator. there must be clear evidence that serious brain damage has occurred and it cannot be cured.
Two senior doctors must perform separate tests at the bedside to determine whether the brain is working or not. These doctors check to see if the cranial nerves that pass through the brain stem and control all vital reflexes are working. They also check to see if the person: has any response to pain.
Brain death results from swelling in the brain; blood flow in the brain ceases and without blood to oxygenate the cells, the tissue dies. It is irreversible. Once brain tissue dies, there is nothing that can be done to heal it.
The study only reported on brain activity recorded over a period of about 15 minutes, including a few minutes after death. In rats, experiments have established that after a few seconds, consciousness is lost. And after 40 seconds, the great majority of neural activity has disappeared.
Brain death diagnosis requires presence of 3 conditions: persistent coma, absence of brainstem reflexes, and lack of ability to breathe independently. Coma is confirmed when a painful stimulus causes no eye opening, no verbal response, and no limb movement in a patient.
Permanent brain damage begins after only 4 minutes without oxygen, and death can occur as soon as 4 to 6 minutes later. Machines called automated external defibrillators (AEDs) can be found in many public places, and are available for home use.
The withdrawal of life supports is always discussed with and agreed by the family (and patient if possible) and this decision is made prior to and independently of any consideration of donation. Only when this decision has been made, is there any consideration of donation.