Pre-emptive coinfiltration of dexamethasone palmitate emulsion with ropivacaine for postoperative pain in patients undergoing major spine surgery: a study protocol for a prospective, randomised controlled, multicentre trial.

Introduction: Patients undergoing major spine surgery usually experience moderate-to-severe postoperative pain. It has been shown that dexamethasone as an adjunct to local anaesthesia (LA) infiltration presented a superior analgesic benefit compared with LA alone in various types of surgeries. However, a recent meta-analysis reported that the overall benefits of dexamethasone infiltration were marginal. Dexamethasone palmitate (DXP) emulsion is a targeted liposteroid. Compared with dexamethasone, DXP has a stronger anti-inflammatory effect, longer duration of action and fewer adverse effects. We hypothesised that the additive analgesic effects of DXP on local incisional infiltration in major spine surgery may have better postoperative analgesic effect, compared with local anaesthetic alone. However, no study has evaluated this so far. The purpose of this trial is to determine whether pre-emptive coinfiltration of DXP emulsion and ropivacaine at surgical site incision will further reduce postoperative opioid requirements and pain scores after spine surgery than that with ropivacaine alone.

Methods And Analysis: This is a prospective, randomised, open-label, blinded endpoint, multicentre study. 124 patients scheduled for elective laminoplasty or laminectomy with no more than three levels will be randomly allocated in a 1:1 ratio into two groups: the intervention group will receive local incision site infiltration with ropivacaine plus DXP; the control group will receive infiltration with ropivacaine alone. All participants will complete a 3 months follow-up. The primary outcome will be the cumulative sufentanil consumption within 24 hours after surgery. The secondary outcomes will include further analgesia outcome assessments, steroid-related side effects and other complications, within the 3 months follow-up period.

Ethics And Dissemination: This study protocol has been approved by the Institutional Review Board of Beijing Tiantan Hospital (KY-2019-112-02-3). All participants will provide a written informed consent. The results will be submitted for publication in a peer-reviewed journals.

Trial Registration Number: NCT05693467.