If your undergraduate GPA was 3.0 or less, unless schools see clear evidence elsewhere of strong academic ability, you will probably not be offered an interview. You may be able to overshadow a GPA that is slightly below standard if you have accumulated other evidence of academic ability subsequent to your undergraduate work (such as through graduate work, repeating undergraduate sciences {if needed}, outstanding leadership roles, and by being very active within the community).
Unfortunately, it comes down to CRNA programs are very competitive. For every previously unfocused person, there are numerous more who were, and who shows up with a transcript attesting to strong academic ability. It is a definite advantage in the selection process. So, how can you escape the stigma of this GPA? The best way to do so would be to demonstrate your academic ability as it is now.
A good place to start would be with anesthesia prerequisite courses if you have not taken them in your undergraduate education. The prerequisites usually consist of courses in statistics, chemistry, or possibly physics. These can be at the undergraduate level, but if you desire to demonstrate your academic ability, it may make more of an impression if you do any coursework at this point at the graduate level. If your prerequisites are completed already, then think about taking some graduate courses. I always advise that you reach out to your program for guidance on which courses would be the most beneficial based on your transcripts. This is also where CSPA services can come in. Program faculty Richard Wilson can review your Transcript and give you guidance.
Performance in sciences such as pharmacology, pathophysiology, or chemistry is good ways to demonstrate your ability in technical graduate courses. You may also take some of the courses from the regular anesthesia curriculum, such as theory and research (if this is allowed, varies from program to program), without being admitted to the program.
If you need to demonstrate your academic ability, consider the quality of the work you do at this point, as well. If you take nursing theory and achieve less than an A in the course, you may not be making the impression you need to. Likewise, if you challenge yourself to more rigorous coursework (such as advanced pathophysiology or pharmacology course), a good performance would speak towards your abilities.