If you are stable and know how to manage your condition (i.e. take your meds that work religiously, avoid alcohol, caffeine and other stimulants and drugs, get enough sleep, eat well, have the right supports in place etc) then you'll be okay. Plenty of people live and function well with Bipolar Disorder, including nurses.
The risk would be if you were unstable in your condition and attempting to care for others. There is no way on earth that you should be attempting to work whilst manic, seriously depressed, ultra-rapid cycling or in a mixed state. You'd put your patients and colleagues at risk because as I'm sure you know, someone in any of these states can be extreme, impulsive and sometimes down right dangerous. You can't care for others until you can care for yourself. But that's not impossible, either!