The risk of myocardial events is greater with opioids. Pain pumps are usual after whipple. I can only guess that you were at some risk which even in pain and if knowing you wouldn't want to take.
Then again hospital care can be fraught.
I was caring for someone in a hospital where the nurses could complete continuing education units while on shift. Otherwise they would have to return on the days off. The resented being interupped from their ed unit completion for patient care. They were all working 12 hour shifts and could be quite grouchy. It was a struggle to get attention for anything.
I'm sorry that you had the experience. You may be experiencing post traumatic stress.