How long is too long to return to ICU?

So I am working back in psych where I have a state pension (not 401k, 403b, etc), but I just left neuro ICU where I worked for 3 years.  So my question to all of you is how long can a nurse be out of the ICU and working in psych before the nurse is seen as "just a psych nurse" and not a good candidate for the ICU anymore?  Thank you all in advance!

To clarify I came back to psych for the pension, it is not my passion.  I was hoping to build some more in my pension fund but don't want to lose my medical skills.  So I am hoping some of you out there will have some insight into this.  Thank you in advance.

I would keep your foot in the door of an ICU setting by picking up a PRN position. Then you won't have to worry about it.

You could start by applying to your former ICU job if they have any job postings. If the manager still remembers you, and your reputation was good, that would be your best bet.

thank you both for the replies... I'm considering the prn option!