If somebody cuts a nonimportant artery in their neck, how long would it take to lose 2 pints of blood, and for a stroke to happen? How long would a person have to be lying there?
A few minutes, if the cut in the neck includes cutting carotid artery.
This varies depending on the circumstances of the patient. If someone is in a coma, it can take months for someone to wake up from a coma.