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
The reason I know is I overheard the anesthesiologist and fentynal was said and I joked “I hope y’all bought it from a reliable dealer”
The room laugh and I went to sleep.