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.