I recently had a patient who experienced hypoxemia rapidly upon the removal of his supplemental oxygen. He described a near death experience similar to those reported by individuals who have been clinically dead or near death and then revived. He described a flash of light and a person who told him that he had to go back. By this time his oxygen status had improved and he was fully alert and orientated.
I’ve previously thought that near death experiences were the perview of the (legitly) dying person and would have refuted the concept that neurochemicals and oxygen deprivation would form the basis of such experiences. I had always thought of it as a mystical journey of a person preparing to enter heaven (or hell as is sometimes reported by converts to Christianity) rather than a symptom of biochemistry. It’s a logical explanation to why people perceive ‘the light’ before they die, but leaves other questions looming larger. How does this explain the religious experiences (meeting Jesus or God and seeing heaven) people have, the perception of floating above and seeing their own body, and the differences in time as experienced by the dead person vs. those around the death-bed? This is the great mystery of death. You won’t know the answer until it happens to you.