[exDemMom]

Maybe they should never have done away with the Guillotine. It was quick, and worked every time it was tried. To keep it humane, they just needed to keep the blade sharp.

A guillotine allows for the possibility that the exécutée remains conscious for a few seconds after beheading, before lack of oxygen kicks in. To be more humane, the exécutée would need to be anesthetized prior to the beheading.

Animal researchers use guillotines. They always anesthetize the animals first.

I once had a guillotine in my office. Finally, after I complained several times, some animal caretakers removed the guillotine. The huge hammers, however, remained in my office until I left.

[Nea Wood]

...the exécutée remains conscious for a few seconds after beheading

I once read an account by someone who witnessed a guy get beheaded in an accident. He said the victim's face saw his headless body and looked horrified for a moment before he died.