First, as far as I know (obviously, I haven't watched every other clinical instructor in action), we (clinical instructors) would never put students on the spot in front of a client and her/his family, just as we would never do that with a colleague (as much for the well-being/confidence of the client and family as the colleague -- don't want someone to have to lie in bed worrying that the people caring for her/him don't know what they're doing!
everyone in healthcare makes an effort to avoid making each other look bad in front of clients/families, for the simple reason that "what goes around, comes around" -- once you start that sort of thing, where does it end?) Simple "do you know what you're supposed to know/are you clear on how to do what you're about to do" questions get asked outside the client rooms and away from hospital staff. If the instructor is in a room with a student and sees the student apparently about to do something questionable/dangerous, you calmly stop what you're doing and ask the student to step out of the room with you (inventing a reason, if necessary) so you can speak in private. So you probably (unless you have a v. unusual clinical instructor) don't have to worry about being put on the spot in front of clients/families or even the hospital staff. The kind of "quiz" questions you're talking about get asked in private or, at worst
, in front of your classmates only (so the whole group can participate in & benefit from the discussion).
Second, yes, we are aware that students are nervous in clinicals and might be more likely to freeze up when asked a question. Unless it's a "how to" question about a procedure you're just about to do, it's usually okay to say, "Ooooh, I know that but I'm drawing a blank at the moment." (Assuming that's true, of course -- if you don't
know and you're BSing the instructor, s/he will figure that out in due time.) We were all nursing students at one time, too, you know!
BTW, one "trick" that I have found helpful over the years in that kind of situation (sudden brain freeze) is to start
talking in very general terms about whatever the topic of the question is, and, once you're talking, the answer you're looking for is likely to occur to you (assuming that it's in there somewhere to begin with). Sort of jump-starts or reboots your brain ...
One other little tip: I would definitely not
say, "If you ask me again later, I'll have an answer ..." I would promptly go find the answer and take it to the instructor
on my own, instead of waiting for her/him to approach me again.
Good luck with your studies and clinical!