Ultrasound-guided erector spinae plane block versus thoracic paravertebral block on postoperative analgesia after laparoscopic nephroureterectomy: study protocol of a randomized, double-blinded, non-inferiority design trial

Introduction: Erector spinae plane block (ESPB) is a novel inter-fascial plane block, which is applied more and more in postoperative pain control, especially in chest surgery. Regional block is advocated in order to decrease opioid consumption and improve analgesia in urological surgery. Therefore, we aimed to explore whether ESPB would have similar analgesia compared with thoracic paravertebral block (TPVB) in laparoscopic nephroureterectomy. Methods and analysis: This prospective, randomized, double-blinded, non-inferiority trial will enroll 166 patients undergoing laparoscopic nephroureterectomy. Participants will be randomly assigned 1:1 into receiving ESPB or TPVB before surgery. Both ultrasound-guided ESPB and TPVB will be performed with an injection of 0.375% ropivacaine 0.4 ml/kg before anesthesia induction. Standardized patients controlled intravenous analgesia (PCIA) will be applied for each patient. The primary endpoint is the joint of cumulative 24 h opioid (sufentanil) consumption and average pain score via numeric rating scale (NRS) at 24 h after surgery. Secondary endpoints include rescued analgesic demand, cumulative opioid consumption, and pain NRS scores at different preset timepoints within 48 h after surgery. Other predefined outcomes include clinical features of blockage, quality of recovery, subjective sleep quality, time to ambulation and diet, and adverse events, as well as length of stay in hospital and anesthesia cost. Discussion: Previous studies investigating the analgesic efficacy of ESPB only concentrated on a single endpoint for postoperative pain evaluation, while studies focusing on the direct comparison between ESPB and TPVB in urological surgery are still lacking. Our study is the first trial in non-inferiority design of comparing ESPB and TPVB in patient undergoing laparoscopic nephroureterectomy, and the primary outcome is the joint endpoint of opioid consumption and pain NRS score.