As Chip193 has said it really depends on what combination the Doctor or Anaesthesiologist decides to use to sedate or anaesthetize the patient.
Propofol also called Diprivan slows the activity of your brain and nervous system. It used to help you relax before and during general anesthesia for surgery or other medical procedures as well as to sedate a patient who is under critical care and needs a mechanical ventilator. Can also be used in combo with Ketamine.
It works very fast , within seconds and you go complete unconscious. It is given intravenously in combination with an opiate like fentanyl some people experience a cold or tingly feeling as it is inject .
As Chip193 stated people do feel euphoric with everything feeling a bit ‘floaty’, as if you are intoxicated on alcohol. However you do wake up with a "bang" alert and orientated.
With drugs like Midazolam or Versed ( benzodiazepines) is used more for conscious sedation but it can be used to induce general anesthesia or for sedation for mechanical ventilation in combination with an opiate for analgesia.
The purpose of conscious sedation is to produce a state of relaxation and/or pain relief by using benzodiazepine-type and narcotic medications, to facilitate performing a procedure such as a biopsy, radiologic imaging study, endoscopic procedure, radiation therapy, or bone marrow aspiration.
It is a bit slower acting than propofol achieving sedation within one to five minutes and peaking within 30 minutes. The effects of Midazolam typically last one hour but may persist for six hours (including the amnesic effect). You simple go into a hypnosis-like compliance but Paradoxical reactions including anxiety, delirium and aggression can occur. Some patients report a "creepy obedience" overcoming them.