Does brain dead mean dead? Does it mean just their brain is dead and not their body? Are they really dead or just likely to become dead? Clearly all the recent news about a brain dead teenager in California has broken open this misunderstood wound. Even NBC News adds to the confusion with irresponsible headlines like: “Brain-dead Teen to Remain on Life Support”. Really? Life support for a dead person?
To answer the questions let’s start with the root of the problem: ventilators. Without ventilators there wouldn’t be these questions. A ventilator is a relatively new tool in medicine. For all intents and purposes it simply breaths for a person. When a patient is not breathing, is ineffectively breathing, or unable to protect their airway (i.e. might choke on their own vomit due to a head injury), a doctor will put a plastic tube through the patients mouth and into their lungs. This tube is attached to a ventilator which regulates the flow of oxygen and the number of times a patient gets a breath. Patients placed on ventilators are severely injured or ill and dying. Without the ventilator giving their body—especially their heart—oxygen, they would die. And that is where the confusion begins. (Video of Mechanical Ventilator)
In some cases the patient does die even while on a ventilator. Without a ventilator it would be simple to see and tell they are dead because without oxygen their heart would quickly stop beating. But with a ventilator the heart can keep beating. In fact, the heart actually beats independently as long as it gets enough oxygen and nutrients. The heart does not need the brain to keep beating.
Anyone that has seen or touched a dead body knows it isn’t hard to distinguish them from a living person: they are cold and well, lifeless. But someone touching a (brain) dead body on a ventilator that is warm, has a heartbeat and a chest rising and falling could hardly be blamed for thinking them alive. Obviously the question becomes: can you tell if someone is really alive or dead on a ventilator because some people do “wake up” after being on a ventilator while others have the “plug pulled” and die, or were they already dead?
You don’t want a dead body hooked up to a ventilator for weeks. It costs a lot of money not to mention being unethical. Of course you also don’t want to turn off a ventilator if a person isn’t really dead. It turns out that it isn’t really complicated to determine if a brain has stopped functioning. While extremely complex the brain can be (please forgive me Tim, my neurologist friend) simply divided into two functional components: conscious and automatic. If you can “show” or determine that these two parts aren’t working than the brain is dead. If the brain is dead the person is dead and the ventilator is only working to help the heart keep beating.
Consciousness may be the fodder of philosophers but for our simplistic discussion it is basically the mind thinking and acting. A living, conscious (brain functioning) person, even on a ventilator should be able to respond to external stimulus – like “blink your eyes”. Additionally, the functioning conscious brain emits energy that can be recorded by an EEG machine. So while consciousness is incomprehensibly complex, determining if a patient has any degree of consciousness is quite simple.
The automatic portion of the brain keeps things happening in the body even without any consciousness. You don’t think (consciousness) about blinking, breathing, digesting or adjusting your blood pressure. These functions are automatic. It turns out that testing to see if the automatic part of your brain is working or indeed dead is easy with a series of bedside tests like seeing if the eye blinks when touched and if a breath is taken as oxygen and carbon dioxide levels change. This is not guess work and it is not subject to change. Once the automatic functions of the brain are determined to be non-functioning, they do not come back. (Criteria for determining Brain Death)