Cardiac arrest patients may experience “new dimensions of reality” once they are revived by performing CPR up to an hour after their hearts stop, suggests a new study.
Recent research on the brain activity of dying people has shed light on the dream-like state some individuals appear to experience before they expire.
These studies, including one published in February last year, seem to provide explanations for reports of people vividly recalling their lives in near-death experiences.
Now, a new study, published in the journal Resuscitation, adds more evidence that people may experience life’s memories flash before their eyes during the near-death experience following cardiac arrest.
The research, led by those from the New York University Grossman School of Medicine, assessed reports from survivors of cardiac arrest who described lucid death experiences that occurred while they were seemingly unconscious.
Fewer than 10 per cent of the 567 patients studied, who received CPR in the hospital, recovered sufficiently to be discharged, scientists said.
Four in 10 patients who survived, however, recalled some degree of consciousness during CPR that could not be captured by standard measures.
In a subset of these patients, about 40 per cent had brain activity that almost returned to normal from a “flatline” state at points even an hour into CPR.
EEG scans of these patients reveal gamma, delta, theta, alpha and beta brain waves associated with higher mental function, indicating they may be having a recall of memories.
Cardiac arrest survivors have long recalled having heightened awareness and powerful, lucid experiences.
In popular literature, this has included “out of body” experiences, observing events without pain or distress, as well as a meaningful evaluation of their past actions and relationships.
The new study finds these experiences of death could be different from hallucinations, delusions, illusions, dreams or CPR-induced consciousness.
Researchers suspect the brain’s processes in such people during this state may be opening access to “new dimensions of reality”, including a lucid recall of all stored memories from early childhood to death.
These new dimensions, according to the study, include experiences of people’s deeper consciousness such as all their memories, thoughts, intentions and actions towards others “from a moral and ethical perspective”.
The latest findings, according to scientists, “opens the door to a systematic exploration of what happens when a person dies”.
“Although doctors have long thought that the brain suffers permanent damage about 10 minutes after the heart stops supplying it with oxygen, our work found that the brain can show signs of electrical recovery long into ongoing CPR,” said study author Sam Parnia from NYU.
“This is the first large study to show that these recollections and brain wave changes may be signs of universal, shared elements of so-called near-death experiences,” Dr Parnia said.
These near-death experiences can provide a glimpse into a real, yet little-understood dimension of human consciousness that becomes uncovered with death.
Researchers said such experiences may also guide the design of new ways to restart the heart or prevent brain injuries and also hold implications for transplantation, raising questions related to the timing of organ donation.
However, scientists agree that research until now has “neither proved nor disproved” the meaning of patients’ experiences and claims of awareness in relation to death.
They called for further studies on the recalled experience surrounding death and the need to further study psychological outcomes emerging out of cardiac arrest as part of the broader post-intensive care syndrome.
“The recalled experience surrounding death now merits further genuine empirical investigation without prejudice,” scientists wrote in the study.