It is under these circumstances that families are asked to understand that their loved one has died. It is also under the same scenario that organ donation is presented as an option in order to give life to others. Brain death occurs when a person has an irreversible, catastrophic brain injury, which causes total cessation of all brain function the upper brain structure and brain stem. Brain death is not a coma or persistent vegetative state.
Brain death is determined in the hospital by one or more physicians not associated with a transplantation team. When someone is brain dead, it means that the brain is no longer working in any capacity and never will again. Other organs, such as the heart, kidneys or liver, can still work for a short time if the breathing machine is left in place, but when brain death is declared, it means the person has died.
Death of the brain can occur from accidental injuries or illness. High blood pressure can also cause bleeding in the brain and result in death. A brain infection, a brain tumor or a traumatic injury may cause the brain to swell and lead to death as well. Doctors examining the patient will conduct a battery of tests to determine whether any brain activity is present.
If all brain activity is absent, the patient is dead. The heart is part of the autonomic nervous system and thus has the ability to beat independently of the brain as long as it has oxygen. The heart will eventually stop beating as all bodily systems begin to stop working shortly after brain death.
Although they can grieve for dead offspring and companions, there is no credible evidence that apes, dogs, crows and bees have minds sufficiently self-aware to be troubled by the insight that one day they will be no more.
Thus, these defense mechanisms must have arisen in recent hominin evolution, in less than 10 million years. Teachings from religious and philosophical traditions have long emphasized the opposite: look squarely into the hollow eyes of death to remove its sting.
Daily meditation on nonbeing lessens its terror. As a scientist with intimations of my own mortality, my reflections turn toward understanding what death is. Anyone who undertakes this quest will soon come to realize that death, this looming presence just over the horizon, is quite ill defined from both a scientific as well as a medical point of view. Throughout history, everyone knew what death was. When somebody stopped breathing and his or her heart ceased beating for more than a few minutes, the person was, quite simply, dead.
Death was a well-demarcated moment in time. All of this changed with the advent of mechanical ventilators and cardiac pacemakers in the middle of the 20th century. Modern high-tech intensive care decoupled the heart and the lungs from the brain that is responsible for mind, thought and action.
In response to these technological developments, in , the famous Report of the Ad Hoc Committee of the Harvard Medical School introduced the concept of death as irreversible coma—that is, loss of brain function.
This adjustment was given the force of law by the Uniform Determination of Death Act in This document defines death as either irreversible cessation of circulatory and respiratory functions or irreversible halting of brain function. Quite simply, when your brain is dead, you are dead. This definition is, by and large, in use throughout most of the advanced world.
The locus of death shifted from the chest to the brain and from public view into the private sphere of the hospital room , with the exact time of actual brain death uncertain. This rapid and widespread acceptance of brain death, reaffirmed by a presidential commission in , is remarkable when compared with the ongoing controversy around abortion and the beginning of life.
It may perhaps be reflective of another little noticed asymmetry—people agonize about what happens in the hereafter but rarely about where they were before being born!
The vast majority of deaths still occur following cardiopulmonary cessation, which then terminates brain functioning as well. Neurological death—specified by irreversible coma, absence of responses, brain stem reflexes or respiration—is uncommon beyond the intensive care unit, where patients with traumatic or anoxic brain injury or toxic-metabolic coma say, following an opioid overdose are typically admitted. Brain death may be the defining factor, but that does not simplify clinical diagnosis—biological processes can persist after the brain shuts down.
For the grieving relatives and friends, it is challenging to understand what is happening. When visiting the ICU, they see the chest moving in and out, they feel a pulse, the skin pallor looks normal, and the body is warm. Looking healthier than some of the other denizens of the ICU, their beloved is now legally a corpse, a beating-heart cadaver. The body is ventilated and kept suspended in this quasi-living state because it is now a potential organ donor.
If permission has been obtained, the organs can be harvested from the cadaver to help the living who need a heart, kidney, liver or lung, which are always in short supply. Brain-dead bodies can continue to grow fingernails, to menstruate, with at least some working immune function that allows them to fight off infections.
There are more than 30 known cases of pregnant brain-dead mothers placed on a ventilator to support gestation of a surviving fetus, born weeks or months in one case days after the mother became brain-dead. In a widely discussed story in the New Yorker , a young woman, Jahi McMath, was maintained on ventilation in a home care setting in New Jersey by her family following her brain death in a hospital in California.
To the law and established medical consensus, she was dead. To her loving family, she was alive for close to five years until she died from bleeding associated with liver failure.
Despite technological advances, biology and medicine still lack a coherent and principled understanding of what precisely defines birth and death—the two bookends that delimit life. Aristotle wrote in De anima more than two millennia ago that any living body is more than the sum of its parts. He taught that the vegetative soul of any organism, whether a plant, animal or person, is the form or the essence of this living thing.
The essence of a vegetative soul encompasses its powers of nutrition, growth and reproduction that depend on the body. The sensitive soul mediates the capacities of both animals and humans to sense the world and their bodies. Of course, this is now increasingly mimicked by artificial-intelligence algorithms. The modern emphasis on machine learning, genomics, proteomics and big data provides the illusion of understanding what the vegetative soul is.
Yet it obscures the depth of our ignorance about what explains the breakdown of the vegetative soul. How can one precisely delimit this body in space are clothing, dental implants and contact lenses part of the body? In the absence of a precise conceptual formulation of when an organism is alive or dead, the concept of irreversibility depends on the technology du jour , which is constantly evolving. What at the beginning of the 20th century was irreversible—cessation of breathing—became reversible by the end of the century.
Select personalised ads. Apply market research to generate audience insights. Measure content performance. Develop and improve products. List of Partners vendors. When I tell people that I'm a paramedic, there are usually some follow-up questions. The most common is, "What's the worst call you've ever had? However, there is a catch. The patient can't be too dead. This is a question of survival, not about zombies or chanting at the full moon.
It begins with whether we're discussing clinical death or biological death. Both mean the patient is technically dead, but each term refers to a different level of permanency. One is fixable; the other is not. First comes clinical death, which is when breathing and blood flow stop.
Clinical death is the same as cardiac arrest ; the heart has stopped beating and blood has stopped flowing. Technically, clinical death requires both the heart and the breathing to stop, but that's just semantics. Breathing and consciousness will cease within a few seconds of the heart stopping. Clinical death is reversible.
Researchers believe there's a window of about four minutes from the moment of cardiac arrest to the development of serious brain damage as you can probably imagine, that's a pretty hard statistic to validate through a random control trial.
If blood flow can be restored—either by cardiopulmonary resuscitation CPR or by getting the heart pumping again—the patient could come back from clinical death. It's not a sure thing; success rates for CPR are pretty dismal.
Those are not good odds for coming back from clinical death. Before we get too morbid here, it's important to note that the application of CPR and of an automated external defibrillator AED increased the chances of survival significantly.
All is not lost with clinical death, but you must act quickly. Biological death, on the other hand, is brain death, and there's no turning back from brain death. That is irreversible death.
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