Hmmmm. You're one of a lucky few, I guess, seeing as how most ICUs don't employ/utilize CNAs at all since the nurses doing the nursing care are doing exclusively primary nursing! If you're in ICU, expect to become ambidextrous in your equipment manipulation (i.e. lines, multiple is putting it mildly), while turning, repositioning, bathing, etc. the icu pts.
So, being skilled in that dept would certainly help. You're going to be busy giving mostly baths, linen changing, pericare, hs care, that sort of thing. Emptying lots of garbage from rooms/dept., emptying foley cath bags after measuring output very carefully and properly documenting/or reporting it to the nurse. I cannot stress how important I & O is in the ICU...lots of intake from IVs, the output is important because it is reflective of how well the kidneys are functioning, the color, odor, consistency, etc. of the urine, so be sure to note those characteristics, also. They may train you in emptying additional lines of output, they will certainly be giving you specialized inservice/orientation on how and what to do....good luck! Oh, and probably will teach you to do fsbs, as well.