Pre-Emptive Incision-Site Infiltration with Ropivacaine Plus Dexamethasone for Postoperative Pain After Supratentorial Craniotomy: A Prospective Randomized Controlled Trial

BACKGROUND: Incision-site infiltration with local anesthetics prevents pain on incision site, but pain relief is limited to the first few postoperative hours. Dexamethasone as an adjuvant to local infiltration successfully achieves better postoperative pain relief; however, this has not been studied in craniotomy patients yet. STUDY DESIGN AND METHODS: This is a prospective, single-center, blinded, randomized, controlled trial included patients aged between 18 and 64 years, ASA physical status of I–II, scheduled for elective supratentorial tumor craniotomy under general anesthesia. We screened patients for enrollment from April 4, 2019 through August 15, 2019. The final study visit of the last patient was conducted on February 13, 2020. We randomly assigned eligible participants (1:1) to either the dexamethasone group who received incision-site infiltration of 0.5% ropivacaine plus 0.033% dexamethasone (N=70) or the control group who received 0.5% ropivacaine alone (N=70). Primary outcome was the cumulative sufentanil consumption (μg) within 48 hours postoperatively. Primary analysis was performed based on the modified intention-to-treat (MITT) principle. RESULTS: Baseline characteristics were similar between the groups (p>0.05). Sufentanil consumption during the first 48 hours postoperatively was 29.0 (10.7) μg in the dexamethasone group and 38.3 (13.7) μg in the control group (mean difference −9.3, 95% CI −13.4 to −5.1; p<0.001). There was no serious adverse effect directly associated with incision-site infiltration or local dexamethasone use. CONCLUSION: The addition of dexamethasone to pre-emptive incision-site infiltration with the local anesthetic can reduce about 27% of opioids consumption and the postoperative pain scores within 72 hours after craniotomy. TRIAL REGISTRATION: ClinicalTrials.Gov (NCT03618264).