TBH, when things are that serious, they don’t have too much time to hang about doing the explanation bit.
When I was in ICU I was fully awake the whole time even though I begged for sedation and was told I couldn’t have it because of how low my BP was, I had neck lines in, several of them, one for drugs of some sort, some kind of tube to take blood, tubes connected to the filter machine, and they were all held in place by some bloody great frame thing which went over the top of my head.
A debrief would be a good idea IMO.
In my case, every traumatic thing which happened to me was then followed by something more traumatic, which then eliminated the previous thing... So prior to going into ICU I crashed and had to be defibrilated, I remember feeling the defibrillator on my chest, although nothing before and after. Then I was taken to ICU and I had all these lines inserted and stayed there for nine days. Then I was moved, and a few days later I sat up one night, felt dizzy, rang the bell and then the crash team arrived. I distinctly remember the consultant saying to me “can you open your eyes for me?” On a couple of occasions, and then talking to the nurse about putting the pads on. Remarking that my heart rate had dropped to ten BPM, and then starting compressions and me begging him to stop. And then oblivion and waking up the next morning in ICU having had a temporary pacemaker inserted and spending the night on a ventilator.I actually thought I was going to have to seek therapy to come to terms with that one, but interestingly it was seeing the crash teams going to other patients on the wards which made things far more easy to deal with. I went from having a complete anxiety attack the first time the crash team came to the patient in the bed next to me, to being extremely awed and fascinated (if that’s not too crass) by just how slick the crash team is. And the fact they seemingly appear from nowhere. one minute all is quiet, and the next about fifteen people seemingly teleport from all directions. 
I did have some quite disturbing dreams in the aftermath, where I was in a gameshow where you jumped into a 300 ft deep swimming pool and the last one not to drown was the winner, 
and pushing up to the top of the pool so as to win, and I think the fact I spent six weeks in hospital was helpful because I went from that level of trauma to the surgery which improved my life quality and then moving down the wards to out, so it was like a process.
I still have some mild triggers, like if my DP leans over me in any way to give me a hug or similar, so we do things differently now, and initially the face masks we now have to wear, but I just had to think of other things to get through that one.
Don’t be afraid to ask for help. Lots of people need it.