Anesthesia Coding Alert

Question: We have a two-surgery claim for a patient, with the payer denying the second procedure. We billed 00942 (Anesthesia for vaginal procedures [including biopsy of labia, vagina, cervix or endometrium]; colpotomy, vaginectomy, colporrhaphy, and open urethral procedures) for the primary procedure. She experienced post-op bleeding and returned to surgery several hours later, for 55 minutes. A different anesthesiologist from our group participated in the second procedure and billed 00400 (Anesthesia for procedures on the integumentary system on the extremities, anterior trunk and perineum; not otherwise specified) with modifier 78 (Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period). The payer denied the second surgery with the reason "when multiple procedural codes are reported for a single anesthetic administration, only the code with the highest anesthesia base unit will be considered." Are [...]