Document resource
Background and Aims Maintaining neuromonitoring integrity is crucial in scoliosis surgery. This study examines the effects of perineural dexamethasone and dexmedetomidine on motor-evoked potentials (MEPs), sedation, and analgesia in pediatric patients receiving erector spinae plane block (ESPB).Methods This study was approved by the Bioethics Committee at Poznan University of Medical Sciences (protocol 538/23) and registered at ClinicalTrials.gov ( NCT06086431). Written informed consent was obtained from all caregivers before enrollment. Ninety pediatric patients undergoing posterior spinal fusion were randomized to receive ESPB with ropivacaine alone (Control), ropivacaine + dexamethasone (DEX, 0.1 mg/kg), or ropivacaine + dexmedetomidine (DEM, 0.1 µg/kg). MEP amplitude, latency, TES stimulus strength, BIS index, postoperative analgesia, and opioid consumption were assessed.Results Dexamethasone significantly increased MEP amplitude (p=0.04) and reduced TES stimulus strength (p=0.04), suggesting improved neuromonitoring conditions. Dexmedetomidine did not alter MEP parameters but resulted in the lowest BIS scores (p=0.05), indicating deeper sedation, as seen in table 1. The time to first rescue analgesia was significantly prolonged in both DEX (12.96 ± 2.03 h) and DEM (11.65 ± 2.95 h) compared to Control (5.15 ± 1.69 h; p<0.0001). Total opioid consumption was significantly lower in the DEX and DEM groups (p<0.0001), with similar reductions in postoperative pain scores (NRS). No significant differences were found in inflammatory markers or blood glucose levels. However, DEM caused 11 cases of bradycardia and 5 cases of hypotension, while no hemodynamic instability was observed in the DEX or Control groups. No nerve injuries occurred, as seen in table 2.Conclusions Dexamethasone enhances neuromonitoring while providing prolonged analgesia and opioid-sparing benefits. Dexmedetomidine offers similar pain relief but is associated with hemodynamic instability, limiting its suitability in pediatric scoliosis surgery. The choice of adjuvant should consider both intraoperative neuromonitoring requirements and patient cardiovascular stability.Abstract OP01 Table 1Changes in cumulative anesthesia, transcranial electrical stimulation, and motor-evoked potential parameters were recorded from the tibialis anterior muscle before and after the surgical correction procedures in three groups of scoliotic patients injected with different pharmacological agents. Mean values and standard deviations are presented. p < 0.05 determines significant statistical differences marked bold.Abstract OP01 Table 2Secondary outcomes. Values are means