Pupil Response in Pain Management

[BabyRN2Be]

I had posted this on another thread in here, but since the other thread was very old, I wasn't too sure that anyone would read it. So, if you all don't mind, I'd like to post it here.

My very close cousin had a CDH baby a few years ago. When they did the surgery, the left the epidural in for pain control for a few days. When the epidural came out, the nurse said that she was monitoring him very closely for pain control. She mentioned something about his pupillary(?) response and that he probably needed some medication at the time.

For my own education, what type of response was she looking for? Do the pupils become sluggish? I've been wondering about it and I thought that I'd ask you all.

I appreciate all your answers and patience with my questions! :)