The last time I researched this, I could not find a single commercial carrier to reimburse a surgical assist who was not a physician, PA, NP, or clinical nurse specialist. Physician with -80 modifier. PA, NP or CNS with -AS modifier. Even finding payors willing to pay for CNS assist was not easy, and (at least in my area) CNS who are certified RNFA are hard to come by, and expect a salary about matching an NP.
Each state determines scope of practice meaning what tasks a licensed healthcare professional may or may not perform. Whether or not your surgical nurse is permitted to legally perform the task is up to your state. The state's nursing board, or education dept or similar is the best place to check whether based on specific credentials what the "surgical nurse" may perform.
Payment is a completely separate issue and is determined by each carrier.
When we had a surgical suite in our office, if it was medically necessary, then a PA would assist. Procedures that the physician did not require a true "assistant at surgery", there would be a LPN, RN, surgical tech or other appropriately trained personnel in the room to prepare instruments, position patient, do counts, document times, etc. We billed and received payment only for cases where a PA assisted and the code allowed for an assist. Having a PA (or NP) there also allows the NPP to write discharge orders, prescriptions, etc. which even an RN cannot do.