Fentanyl Is actually an effective sedative used every day in hospitals across the country to lightly put people under for surgeries that don’t require going deep under.
Of course it’s used while being monitored by trained anesthesiologists.
I am a retired Nurse Anesthetist. We used high Dose fentanyl for open hearts. Used moderate dose fentanyl for vascular cases. Excellent cardiovascular vascular stability. Fentanyl does not provide amnesia. Often we used versed with fentanyl for cases requiring mild sedation