Carbon Dioxide a Clue in Near-Death Experiences

High Levels of Carbon Dioxide During Cardiac Arrest May Cause Patients' Strange Sensations, Researchers Say

Medically Reviewed by Laura J. Martin, MD on April 07, 2010
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April 7, 2010 -- There may be a sound scientific explanation behind the strange near-death experiences reported by many people who go into cardiac arrest.

A new study suggests a buildup of carbon dioxide in the blood during cardiac arrest may cause the sensations of life flashing before the eyes, feelings of peace and joy, and encounters with mystical entities associated with near-death experiences.

Researchers say about a fifth of people who survive cardiac arrest report near-death experiences.

During cardiac arrest, the heart ceases to function properly and dangerous levels of carbon dioxide build up in the blood, but researchers say the association between carbon dioxide and near-death experiences (NDEs) has never been reported before.

"Our study adds new and important information to the field of NDE phenomena,” researcher Zalika Klemenc-Ketis of the University of Maribor in Slovenia, says in a news release. “We found that in those patients who experienced the phenomenon, blood carbon dioxide levels were significantly higher than in those who did not."

In the study, published in Critical Care, researchers examined 52 cases of cardiac arrest where the patient survived. Eleven (22%) reported a near-death experience.

The results showed people who reported a near-death experience had much higher concentrations of carbon dioxide in their blood than the others.