Near-death and brain chemicals… best way give character a strong hallucination before dying?

I’m working on a short story involving inner, personal experiences during the few moments before death, connected to the release of neurotransmitters at the moment of death. Basically, the entire story takes place in a time-dilation hallucination caused by that last surge of chemicals in the brain.

If my character experiences a traumatic brain injury, I’m assuming that they will not experience the same near-death hallucinations compared to other deaths (from like a shot to the gut). I’m also assuming that taking drugs prior to death would alter the experience.

Does anyone know if there is a type of death that would maximize the release of these “trippy chemicals” in the final moment? Or any specific types of deaths that I should avoid?