It really depends on the program.
Generally, the smaller and more sporadic the volume of patients, the more you will be on call-- if that makes sense.
Big players (in major metro areas) are running acute patients around the clock, 24/7/365. Those larger facilities often schedule RN's on shift-work, like any other position. And, with more RN's, the call time is therefore spread out.
I was fortunate that my call time was usually limited to one day a week, and one Sunday every four to five weeks.
Yes, call stinks in dialysis. Someone above mentioned the "sickening feeling." The only thing worse is to get home after a 13 hour day; collapse on the pillow, and then have the phone ring.
However, I loved acutes. It is one of the last autonomous RN positions in the hospital.
A lot of people hate it because in my estimation, they're simply afraid. It takes a while to feel comfortable. I hated it at first, but grew to love it.
Same with a coworker who was forced by circumstance to work acutes non-stop for three months. She hated acutes, and avoided it all costs. But, by the end of that time, she decided acutes was way better than outpatient and she never looked back. The autonomy, knowledge gained, and getting to collaborate with so many departments, docs, and RN's throughout the hospital is wonderful.
Love love love acutes!