Comparison of different concentrations of ropivacaine in epidural anesthesia for percutaneous transforaminal endoscopic discectomy: a randomized controlled trial

Background This study investigated the optimal concentration of ropivacaine epidural anesthesia for clinical use in percutaneous transforaminal endoscopic discectomy (PTED) by comparing the effects of different concentrations. Methods Seventy patients scheduled for their first PTED procedure were enrolled in this randomized controlled trial. Patients were randomized to receive ropivacaine at varying concentrations (0.3% or 0.4%). Primary outcome measures included the numeric rating scale (NRS) and hip extension level (HEL). Secondary outcome measures included intraoperative fentanyl dosage and postoperative complications. ResultsOne patient withdrew due to severe postoperative complications. The remaining 69 patients were allocated to the 0.3% (n = 34) and 0.4% (n = 35) groups, respectively. Baseline characteristics showed no significant differences between the two groups (P > 0.05). The NRS score was significantly lower in the 0.4% group than in the 0.3% group (P < 0.01), whereas the HEL score was significantly higher (P < 0.001). The average fentanyl dose in the 0.4% group was significantly lower than that in the 0.3% group (P < 0.01). Postoperative complications occurred in five and two patients in the 0.3% and 0.4% groups, respectively. Conclusion Although 0.4% ropivacaine (20 mL) impacts muscle strength, it does not impede PTED surgery. Given its effective analgesic properties and few postoperative complications, 0.4% ropivacaine can be considered a preferred dose for PTED.