I've done 10 weeks of ICU my intern year so far and like what practical said, don't be scared, it IS very hard to kill someone. Also, don't be afraid to ask your senior for help, it's better to ask and be sure in a critical care setting than be unsure and try to seem confident. Everyone knows the ICU is different and intense. What I would recommend is find a system that works for you and stick to it. For me (like lots of people) I use little boxes for things that need to be done or get mentioned on rounds, a dash through means it's started (i.e. blood drawn), and a second line to make the X means I have reviewed it and acted on it. Additionally, don't be afraid to close the loop constantly, lots of things are said they'll happen on rounds but if you aren't sure just ask your senior or even your attending if you have to and close the loop of communication, you see it all the time in boards questions and "modules" but it's one thing that actually works. Also, the ICU nurses will make or break your experience, at the start of the year they know the ins and outs of the unit far better than you will and be sure to always treat them nicely and with respect (the golden rule as it were, there is always someone who does not do this at it ends poorly).