Brian, Thanks for the interesting question. Near death experiences have figured prominently in many fiction books (such as Bliss) and movies (such as Flatliners), as well as in non-fiction memoirs (such as Dying To Be Me). In your particular story, you’ll want your character to have a swift demise, and a rapid recovery to a near healthy state. If you are far from medical help, you’ll need a condition that can be easily reversed by the intervention of a non-physician, a Good Samaritan. The key to a near death experience is lack of oxygen supply to the brain, causing disorderly firing of brain cells, neurons. Scientifically, the sensations experienced at near death, such as “moving toward the light” can be explained as brain cell shutdown phenomenon related to internal, cellular suffocation. Metaphysically, these sensations have been experienced and interpreted as having all sorts of personal, religious, and cosmic explanations.

An allergic reaction, known as anaphylaxis, could set the scene for your character. Up to 2% of the population will get anaphylaxis during their lifetime. Away from medical help, you character could get a bee sting or eat a peanut to set off a series of allergic events. Anaphylaxis is a rapid, hyper-immune, inflammatory response to a substance in contact with the body. It starts with itching and rash, and can progress rapidly to low blood pressure, fainting, and unconsciousness. A cascade of toxic substances released from white blood cells, and mast cells in body tissue, attack every organ system at once. Tissue swelling is dramatic, especially of the head and neck. Ultimately, swelling causes blockage of air passages in the throat (airway edema) and suffocation. Partial airway blockage can cause several minutes of mild oxygen deprivation in the brain, where brain cells start to shut down, but do not die. Complete airway blockage causes total oxygen starvation in the brain, followed by brain death 5 minutes later. Once complete airway blockage starts, you’ve got less than 5 minutes to administer a cure. And the cure is an injection of adrenaline (epinephrine), easily administered by a passerby who (not uncommonly) happens to be carrying an EPI-pen, a unit dose injector, pen-like device for treatment of severe allergic reactions. Many people known to be at high risk of allergic reactions carry EPI-pens as a precaution. One quick stab with the EPI-pen will cause almost immediate, dramatic reversal of the allergic reaction, the anaphylaxis, so your character lives to tell the story of their near death experience.

H.S. Clark, MD