Doctors declare patients dead when they either have “‘irreversible cessation of circulatory and respiratory functions’, or ‘irreversible cessation of all functions of the entire brain, including the brainstem’” (Powell, 2014). The first criteria categorizes heart and organ failure, while the second describes brain failure-–or brain death.
Scientists distinguish death in these two ways as a result of the advancement of modern medicine and research. For instance, when the ventilator was introduced, it became possible for someone to evade this first criteria, and created the need to distinguish brain death from cardiac death. In his presentation “What is the Difference Between Death and Brain Death,” Dr. Joesph Vukov states that due to ventilators and like-machines, people appear to be asleep, even though they are brain dead, because technology keeps circulating their blood, making them warm to the touch. Furthermore, loved ones claim that a brain dead person still senses and reacts to them. The person looks and feels alive; however, despite these appearances, the person’s brain is not capable of any function. By the second criteria, they are dead. The advancement of the ventilator and like-machines affectively blurred the line between dead and alive. Thus, as technology continues to develop, the definition of death needs to further develop as well.
One example of advancing technology challenging the current definition of death is from researchers at Yale School of Medicine, where they successfully returned circulation and electrical activity to dead pig brains. Four hours after death, researchers placed the brains into BrainEx, a machine in which computers controlled the pumping and filtration of special blood into the brains. Two hours later, the scientists observed that the cells in which the blood flowed to maintained important structural features, while the cells that received no blood nourishment showed normal signs of decay. The cells receiving blood took nutrients, like glucose and oxygen, and then secreted carbon dioxide. Both of these processes are signs of larger metabolic activity. Additionally, the cells conducted small-scale electrical activity. However, researchers did not observe any large-scale activity, meaning that there were no any signs of revived consciousness. In fact, the researchers stood by BrainEx with techniques to stop any large-scale electrical activity, immediately. Consciousness was not the goal of their study, for operating on a conscious brain enters into a whole set of ethical issues that they were already pushing. Researchers stressed that these tests were not an attempt to bring the brains fully back to life, but rather they were interested in new therapies for stroke and heart attack victims, as well as other traumatic events in which the brain is deprived from blood and oxygen.
On the other hand, neuroscientists disconnected from the study commented on how these techniques may apply to human brains. Human and pigs’ brains resemble each other by their complexity and size, making these suggestions relatively possible. If this technology advances and applies to humans, the definition of death will need to change once again. BrainEx may be a technique in which the second criteria of death could be evaded. Vukov suggests that death may not be as black and white as it is defined right now, and this Yale research supports his suggestion. It will be interesting to see how the definitions for death–brain and circulatory–adapt as our medicine advances.
Also, I must note that this connection to human brains is extremely dangerous as people read about this study. With brain death already so misunderstood, these suggestions will most likely further peoples’ confusion. At first glance, loved ones may believe that it is possible to fully revive the brain, but in fact researchers state that they are not close to this reality. Vukov states that some confusion surrounding brain death stems from miscommunications between doctors and family members. In response to this study, it is imperative that doctors are now even more precise and clear as they explain the tragic and complicated concept of brain death.
References
Greshko, M. (2019, April 17). Pig brains partially revived hours after death-what it means for people. Retrieved April 28, 2019, from https://www.nationalgeographic.com/science/2019/04/pig-brains-partially-revived-what-it-means-for-medicine-death-ethics/
Powell, T. (2014). Brain Death: What Health Professionals Should Know. American Journal of Critical Care, 23(3), 263- 266. doi:10.4037/ajcc2014721
This article is from our assigned class readings.
Ritter, M. (2019, April 17). Scientists Restore Some Brain Activity in Slaughtered Pigs. Retrieved April 28, 2019, from http://time.com/5572612/pig-brain-activity-science/
Vukov, J. (2019, April 2). What is the Difference Between Death and Brain Death? Lecture presented at Loyola University Neuroscience Seminar in Loyola University Chicago, Chicago.
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