How might life replay before death? Many survivors of near-death experiences have told stories about how every stage of life flashed before their eyes. These visions have ranged from moral evaluations of how their life was lived to highlights of their achievements and regrets. Until now, these were just stories—recounts from one person to another. However, Sam Parnia, an NYU Langone Medical Centre Associate Professor of Medicine, and his lab recently found support for this concept of consciousness before death.
Parnia and his colleagues conducted a seven-year-long study in the US and UK which involved 567 patients who received CPR following cardiac arrest. Out of these patients, fifty-three survived and twenty-eight completed interviews. Eleven of these patients reported memories and perceptions that were suggestive of consciousness during cardiac arrest. In addition to interviewing these patients, the study also collected recounts of near-death experiences from other cardiac arrest survivors in the community. One of the main challenges was the low survival rate of patients, a tragic circumstance that limited the interviews that could be collected.
In the study, resuscitated patients exhibited signs that they were conscious during experiences of death. “I could see what was going on. […] I stood next to the bed. It was very odd,” one patient said. “I remember seeing my dad,” another patient said. In line with this, one of the key discoveries Parnia’s lab presented was how the brain remained robust and active thirty-five to sixty minutes after starting CPR. They detected brainwaves well into CPR that suggested normal brain activity.
This discovery redefined current assumptions about brain activity after oxygen deprivation. “The brain dying after five to ten minutes due to oxygen deprivation is incorrect,” Parnia said. The study challenged the conventional wisdom that the brain is severely damaged after five to ten minutes without oxygen—a claim that implied CPR should not be performed for more than ten minutes because the patient would be in a vegetative state if revived. This study suggests potential for the development of medicine that preserves the brain after resuscitation and brings back patients with full consciousness in the future.
Not only is Parnia’s project interesting to the field of consciousness in cardiac arrest,
but it is also intriguing to the wider public. The lab categorized patient recollections based on themes to further support recounts that have simply been passed by word of mouth. The study presents itself as a leap forward in modern medicine as it fosters an understanding of the relationship between death and consciousness.
An understanding of the relationship between consciousness, life, and death could build solid foundations for end-of-life care. “Just because a patient cannot respond to the stimuli or show signs of awareness, we should not always assume that the patient does not sense or hear what we are doing or talking about,” said Linh Tran, a physician involved in the study.
“We’d like to explore in more detail in real time what happens to the brain across the
entire spectrum as well as consciousness for ever longer periods of time between life and
death,” Parnia added. Ultimately, understanding the role of consciousness in life and death is the next step to understanding human existence—the journey that Parnia and his lab have begun to explore.