Does Perineural Dexamethasone Prolong the Time to First Rescue Opioid Analgesia Compared With Intravenous Dexamethasone in Pediatric Hip Surgery? A Randomized Blinded Trial

Background The pericapsular nerve group (PENG) block is an increasingly utilized regional anesthesia technique for pediatric hip surgery. Dexamethasone prolongs the duration of peripheral nerve blocks and can be administered either intravenously or perineurally; however, the comparative pediatric evidence on postoperative analgesia and metabolic effects with these two routes is limited. Questions/purposes (1) Does perineural dexamethasone prolong the time to first rescue opioid analgesia compared with intravenous dexamethasone when used as an adjunct to PENG block in pediatric hip surgery? (2) Does perineural dexamethasone reduce postoperative opioid consumption and pain intensity? (3) Does the route of dexamethasone administration influence postoperative inflammatory markers and blood glucose levels? (4) Is perineural dexamethasone associated with an increased risk of neurologic complications? Methods This randomized, blinded trial was conducted at a single urban tertiary university referral center in Poznań, Poland, providing subspecialty pediatric orthopaedic care. Parents and caregivers, treating anesthesiologists, surgeons, and outcome assessors were unaware of group allocation. Between February 2025 and March 2026, we assessed 72 children scheduled for elective reconstructive hip surgery. Children age 3 months to 6 years with developmental dysplasia of the hip or neurogenic hip displacement associated with cerebral palsy were considered potentially eligible. Of the 72 children assessed, 92% (66) met the eligibility criteria. Nine percent (6 of 66) of these children were not enrolled because four families declined participation and two declined regional anesthesia. The remaining 83% (60 of 72) were randomized. No participants were lost during the 48-hour in-hospital follow-up or had incomplete outcome data, and all 60 were included in the analysis. The perineural and intravenous groups had mean ± SD ages of 4.8 ± 1.2 and 5.2 ± 1.1 years, respectively; 47% (14 of 30) and 50% (15 of 30) were boys, and 70% (21 of 30) and 73% (22 of 30) had developmental dysplasia of the hip. The remaining children had neurogenic hip displacement associated with cerebral palsy. There were no clinically important between-group differences in these baseline characteristics. All patients received standardized spinal anesthesia and multimodal postoperative analgesia consisting of paracetamol 15 mg/kg and metamizole 15 mg/kg every 6 hours, ibuprofen 10 mg/kg every 8 hours, and rescue nalbuphine 0.1 mg/kg for Face, Legs, Activity, Cry, Consolability (FLACC) scores of ≥ 4. The primary endpoint was time to first rescue opioid analgesia within 48 hours. Secondary endpoints included total opioid consumption, postoperative pain scores, inflammatory markers (neutrophil-to-lymphocyte ratio [NLR] and platelet-to-lymphocyte ratio [PLR]), blood glucose levels, and peripheral nerve injury assessed at 12, 24, and 48 hours. Results We found no difference between the perineural and intravenous dexamethasone groups in time to first rescue opioid analgesia after adjustment for age, body weight, and duration of surgery (HR 0.56 [95% confidence interval (CI) 0.28 to 1.08]; p = 0.08). Perineural dexamethasone reduced total opioid consumption during the first 48 postoperative hours (mean ± SD 0.131 ± 0.048 versus 0.225 ± 0.053 mg/kg morphine milligram equivalents (MMEs), mean difference -0.095 mg/kg [95% CI -0.121 to -0.068]; p < 0.001), corresponding to approximately 42% lower mean opioid consumption and an absolute difference of approximately 1.9 mg MME for a child weighing 20 kg. No differences were observed in NLR or PLR between groups, whereas mean ± SD blood glucose levels were lower in the perineural dexamethasone group at 12 hours (112 ± 17 versus 139 ± 20 mg/dL; p < 0.001) and 24 hours (112 ± 14 versus 134 ± 25 mg/dL; p < 0.001). No neurologic complications occurred in either group during the 48-hour follow-up period. Conclusion After adjustment for age, body weight, and duration of surgery, we found no difference between perineural and intravenous dexamethasone in time to first rescue opioid analgesia. Perineural dexamethasone was associated with lower opioid consumption and lower early postoperative blood glucose levels. Larger multicenter studies are needed to evaluate these findings in pediatric regional anesthesia. Level of Evidence Level I, therapeutic study.