It’s been awhile since I’ve posted but I will try to write more this year! I am alive and that’s the topic I’ll be writing about.
Some days working in a hospital you see awful things that you wouldn’t see elsewhere. Our brains – the seats of our consciousness and basis of personality – can be damaged beyond repair and yet the patient has still not completely ceased bodily functions. These cases stick with me because it looks like limbo between life and death. The burning question is, if you are brain dead, are you closer to one than the other?
The Right-to-Die Court Battle
It is hard to come to grips with life and death especially if it is not cut and dry. Many of us remember Terry Shiavo’s case in the US which culminated in a court battle for the right-to-die. She had been found face down and unconscious having suffered cardiac arrest in February of 1990. This was the result of drinking liquids most of the day (about 10-15 glasses of iced tea). They found she had hypokalemia, otherwise known as low potassium levels. Electrolytes are vital for the heart where imbalances such as hypokalemia can cause severe heart abnormalities. Hypokalemia can be caused by excessive fluids or vomiting which can be often found in bulimic patients. She was diagnosed as being in a permanent vegetative state after a year -where the person is unconscious but there are responses to stimuli such as light. Involuntary movement such as teeth grinding, facial movements and even yawning may occur. After several months to a year the chances of recovering from such a state is very low. Eventually, after many court battles the feeding tube was removed and she died in March 2005. There has been controversy regarding the cause of her initial medical incident, but the autopsy nonetheless found her brain to have suffered severe hypoxia.
Brain Death!
Let’s turn to brain death. According to the American Academy of Neurology, the brain can no longer function at all. Medication will help the heart to keep going and a ventilator will allow the patient to receive oxygen. You can support the body this way for days or even weeks – but brain death is permanent. They will not wake up. It is important to note that there may be different terminologies regarding brain death. For brain death only involving the cerebrum, the brain stem may be mostly intact, and breathing can continue as well as the heartbeat – unaided. If the brain death involves the brain stem, then external assistance is required to keep the bodies metabolic processes going.
What are the Criteria?
There is a lot of criteria for diagnosing brain death and although it may vary the majority will be the same.
The person must be in a permanent coma. The causes of coma can be many, including diabetes – blood sugar that’s too high or too low. It could also be hypoxia where there is a shortage of oxygenated blood to the brain. A person may suffer from hypoxia if they have had a heart attack or almost drowned. CPR is essential as soon as an event occurs to help circumvent this. Infections can also cause coma such as encephalitis and meningitis that may cause inflammation of the brain, spinal cord or surrounding tissues. Stroke can cause blood flow to be stopped to parts of the brain through either a blood clot or burst blood vessel. This can create the results we are more familiar with like speech impairment, paralysis, memory problems and sometimes coma. Drug overdoses, toxins, carbon monoxide and other drugs can cause brain damage and coma as well. Traumatic brain injuries are the obvious cause of comas with violence or vehicular accidents damaging the brain.
Scales Used to Assess Coma
There are scales to assess the severity of a coma such as the AVPU scale which stands for: Alert Vocal stimuli Painful stimuli Unconscious. Another scale used regularly is the Glasgow Coma Scale. http://www.glasgowcomascale.org/. These look at how the patient acts and reacts to a list of criteria with results ranging from mild to severe coma. Some comas may be induced by doctors giving a drug such as propofol to get the brain time to heal.
Reflexes
The brainstem is key in assessing brain death. They look to see if these brainstem reflexes no longer work. The brain stem is one our most ancient parts of the brain which has three parts: the pons, the midbrain, and the medulla oblongata. When people talk about the reptilian part of the brain this is what they’re talking about.
It controls messages from the body to the brain., such as breathing, swallowing, heart rate, blood pressure, and consciousness. The following are some of the reflexes that are used to assess brain death. Electroencephalography or EEG is often done in conjunction to see the electrical activity of the brain during these tests by placing electrodes on the scalp.
Apnea testing is done as well to see the respiratory efforts of the patient and can be seen by temporarily disconnecting them from their ventilator while being monitored.
These test the brainstem but there are reflexes not found in the brainstem such as the kneejerk reflex. That is housed in the spinal cord – nothing to do with the brain. This can lead to false hope when seeing someone with brain death. The Lazarus sign conjures up images of Jesus bringing someone back from the dead. Its appearance is something to behold but it does not indicate anything about a functioning brain. The following video shows an example of how just because a patient is moving, it doesn’t signify they are alive.
A Prisoner in Your Own Home
These tests may not be enough. Why is that? Well, what if it’s uncertain. If the brainstem is partially damaged for example or if there is massive facial trauma that would not let you to properly assess the tests. Some places in the world can require additional tests to confirm it. There is a terrifying reason that I support additional tests and that is called Locked-In Syndrome. This condition which comes from the brainstem being selectively damaged (particularly the pons), paralyzes most facial muscles although some eye movement may remain. The patient may initially be in a coma but then regain consciousness even though they cannot express it. The thought of being trapped in my body with little to no ways of communicating is one of my worst nightmares and it might be one of yours now too.
Light at the End of the Tunnel
Neuroimaging provides much more information to confirm brain death. In Canada, we accept two neuroimaging procedures to assist in the diagnosis. These are cerebral angiography and nuclear medicine perfusion studies.
Cerebral angiography uses the injection of contrast media. The confirming sign is the absent or minimal filling of intracranial arteries at the entry to the skull. Absent flow is expected in the parenchymal and venous phases of the angiogram. The downside to these studies is that the contrast media may cause damage to the organs remaining if they are to be transplanted.
Once someone is brain-dead the body can survive for a few days to around a week or so but once you are brain-dead, you’re actually considered legally dead.
The diagnosis is important for people awaiting organ transplants. Many countries are desperate for organ donors. The following shocking article shows that drug addicts are sometimes being used as donors – even when they have died of overdose. People are desperate for transplants.
http://www.telegraph.co.uk/news/uknews/1572091/Organs-from-drug-addicts-used-in-transplants.html
But what about the chances of someone coming back to life after being diagnosed as brain dead? Should we hold off on the organ transplants until then? Unfortunately, brain death is death. There have never been any cases of someone coming back. It is irreversible. It is final. You’re gone. You’re done. Finito.
References
1. Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014“. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436
2. Brain Death Dr Gita Nath Consultant Anaesthetist – ppt video online download. (2019). Retrieved from https://slideplayer.com/slide/4762077/
3. Brain death presentation. (2019). Retrieved from https://www.slideshare.net/SolomonAlemu2/brain-death-presentation
4. Understanding Brain Death « Finger Lakes Donor Recovery Network. (2019). Retrieved from http://www.donorrecovery.org/learn/understanding-brain-death/
5. Zuckier, L., & Kolano, J. (2008). Radionuclide Studies in the Determination of Brain Death: Criteria, Concepts, and Controversies. Seminars In Nuclear Medicine, 38(4), 262-273. doi: 10.1053/j.semnuclmed.2008.03.003