Dexamethasone as a perineural adjuvant to a ropivacaine popliteal sciatic nerve block for pediatric foot surgery: a randomized, double-blind, placebo-controlled trial.

Background: This study assessed the effect of perineural dexamethasone on block duration, opioid requirement, blood glucose levels, and stress response to surgery as measured by the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), following pediatric foot and ankle surgery.

Methods: In this parallel, double-blinded randomized controlled trial, 90 children (ages 2-5 years, >5 kg) scheduled for foot or ankle surgery under spinal anesthesia with ultrasound-guided single-shot popliteal sciatic nerve block were randomized into 3 groups: 0.5% ropivacaine with saline (control), 0.5% ropivacaine plus dexamethasone 0.1 mg/kg (DEX0.1), and 0.5% ropivacaine plus dexamethasone 0.05 mg/kg (DEX0.05). Primary outcome was the time to first rescue opioid analgesia. Secondary outcomes included motor block duration, pain scores, NLR, PLR, and blood glucose levels.

Results: Time to first rescue opioid analgesia was significantly longer in the DEX0.1 group compared with the DEX0.05 group (18.4 hours, SD 2.6 hours vs 16 hours, SD 2.8 hours), with a mean difference of 2.2 hours (95% CI 0.7 to 3.6), p<0.01; and the control group (8.5 hours, SD 1.5 hours), with a mean difference of -9.9 (95% CI -11.4 to -8.4), p<0.001. Motor block was significantly longer in the DEX0.1 group (17.3 hours, SD 2.5 hours) compared with the DEX0.05 (15.2 hours, SD 2.7 hours; p<0.01) and control groups (7.8±1.1, p<0.001). Total opioid consumption was significantly lower in the DEX0.1 group compared with the control group (p=0.01). NLR, PLR, and glucose levels did not differ significantly between the groups at baseline, 24 hours, and 48 hours post surgery.

Conclusions: Perineural dexamethasone significantly prolonged postoperative motor block duration and did not influence blood glucose, NLR, or PLR levels.

Trial registration number: NCT06086418.