Anesthesia Coding

We currently have CRNA's working under the supervision of an Anesthesiologist in our ASC. We bill with the appropriate QK and QX modifers. If the anesthesiologist is performing his own anesthesia and not supervising he will be billed with AA modifier. The CRNA's will be supervised by the surgeon during this time. Do I still bill with the QX modifier for the CRNA? This is a 50% cut in reimbursement.