A new study suggest that too much CO2 in the blood during heart attacks is the likely cause of the so-called Near-Death Experience:
In the new study, researchers investigated whether different levels of oxygen and carbon dioxide—the main blood gases—play a role in the mysterious phenomenon.
The team studied 52 heart attack patients who had been admitted to three major hospitals and were eventually resuscitated. Eleven of the patients reported near-death experiences.
During cardiac arrest and resuscitation, blood gases such as CO2 rise or fall because of the lack of circulation and breathing.
“We found that in those patients who experienced the phenomenon, blood carbon-dioxide levels were significantly higher than in those who did not,” said team member Zalika Klemenc-Ketis, of the University of Maribor in Slovenia.
The article goes on to mention that other factors such as age, sex, religious belief, drugs used during resuscitation or how long it took to revive them had no impact on whether or not patients reported an NDE.
The study didn’t speculate on how excessive CO2 would result in an NDE, just that it appears to be the cause. This isn’t too surprising given the fact that people at high altitudes without a pressure suit or who have inhaled a lot of CO2 report NDE-like effects as well.
It’s certainly not conclusive yet, but it is a good start into investigating the phenomena.