Don't be so quick to doubt your critical care experience. You now work in an ICU and that is all you need to get in a program.
Try to learn all you can on how to manage your patients and know the why in what you are doing.
I just got done doing a research article in class on admission criteria for CRNA schools
and it listed SICU as the 58% of apps accepted to school but there is still the other 42% of the other units and areas that were accepted.
I had my experience from CCU and the ER. I do not feel that having SICU would have made any difference on my performance in CRNA school. I got all the drips,vents,swan lines,codes experience needed.
However I believe that my ER experience put me ahead of those that did not have ER when it came to peds. I had already had much experience handling peds from working ER and this allowed me to excel with peds cases in anes school. Most of my classmates were terrified when it came to doing peds for they had only worked with adults in the units. I also had some experience with occ. OB doing ER which is something else you don't get in the unit.
If you did anything I would go to a peds ER and add to your hands on experience, you've already got the critical care experience.
Hope this helps, Lee.