Usefulness of Stepwise Implementation of Multimodal Analgesia for Postoperative Pain after Simultaneous Anteroposterior Spinal Fusion with Oblique Lateral Interbody Fusion

Postoperative pain after simultaneous anteroposterior spinal fusion involving oblique lateral interbody fusion can be substantial because the procedure involves both anterolateral and posterior surgical fields. This retrospective comparative study evaluated postoperative analgesic outcomes after the stepwise implementation of a multimodal analgesia protocol developed by a multidisciplinary team including pharmacists. The protocol was sequentially expanded from intravenous patient-controlled analgesia (IV-PCA) alone to IV-PCA plus flurbiprofen axetil (FA) and then to IV-PCA plus FA and ropivacaine (ROP) local infiltration analgesia. Patients who underwent surgery between January 2025 and March 2026 were classified by implementation period: IV-PCA alone (n = 15), IV-PCA plus FA (n = 25), or IV-PCA plus FA and ROP (n = 11). The primary outcomes were numerical rating scale (NRS) scores on the day of surgery and postoperative day 1. Secondary outcomes included the number of patients receiving rescue analgesia, the number of rescue analgesic administrations, perioperative changes in creatinine clearance, and postoperative nausea and vomiting. Compared with the IV-PCA group, the IV-PCA plus FA and ROP group had significantly lower NRS scores on the day of surgery and postoperative day 1 and fewer rescue analgesic administrations on the day of surgery. Creatinine clearance did not change significantly perioperatively in the FA-treated groups, and the incidence of postoperative nausea and vomiting did not differ significantly among the groups. Stepwise implementation of the protocol incorporating FA and ROP was associated with better early postoperative analgesic outcomes.