Erector Spinae Plane Block at Two Volumes vs. Standard Analgesia for Retrograde Intrarenal Surgery: A Randomised Controlled Trial.

Abstract

Objective: To evaluate whether a T11 erector spinae plane block (ESPB) administered at two different volumes reduces postoperative tramadol consumption following retrograde intrarenal surgery (RIRS).

Study design: A randomised, single-blind controlled trial. Place and Duration of the Study: Department of Urology, Kahramanmaras Sutcu Imam University Health Practice and Research Hospital, Kahramanmaras, Turkiye, between September 2023 and July 2024.

Methodology: Sixty patients with American Society of Anesthesiologists (ASA) physical status I-II, aged 18-65 years and undergoing RIRS, were randomised into three groups (n = 20 each): a control group (no block; intravenous tramadol 1 mg/kg), an ultrasound-guided erector spinae plane block (ESPB) group receiving 20 mL, and an ESPB group receiving 30 mL, all using 0.5% bupivacaine diluted to the volume. ESPB was performed preoperatively at T11 under ultrasound guidance. All patients received tramadol via patient-controlled analgesia. The primary outcome was 24-hour tramadol consumption. Secondary outcomes included visual analogue scale (VAS) scores, rescue analgesia, nausea/vomiting, and haemodynamics. Continuous variables were analysed using the Kruskal-Wallis test; categorical variables were analysed using the chi-square test (p <0.05).

Results: Groups were comparable. Total tramadol consumption differed significantly among the groups (p <0.001). Post hoc analysis showed that both the ESPB-20 and ESPB-30 groups had significantly lower tramadol consumption than the control group, whereas no significant difference was observed between the ESPB groups. VAS scores, rescue analgesia, and adverse effects were similar. No complications occurred.

Conclusion: Preoperative T11 ESPB reduces opioid consumption after RIRS, with 20 mL appearing sufficient.

Key words: Erector spinae plane block, Retrograde intrarenal surgery, Postoperative pain, Tramadol, Regional anaesthesia.