The anesthetic efficacy of ultrasound-guided lumbar plexus combined with quadratus lumborum block with Shamrock approach in total hip arthroplasty: study protocol for a randomized controlled trial

INTRODUCTION: The lumbar plexus originates from multiple segments of the spinal cord. Both single-level lumbar plexus block (LPB) and transmuscular quadratus lumborum block (TQLB) are commonly used to provide analgesia for the patients undergoing total hip arthroplasty (THA). However, neither of them can completely cover the lumbar plexus. Multiple-level LPB is also not recommended since this expert technique involves more potential risks. To achieve a better anesthetic effect and avoid risks, we propose to combine ultrasound-guided LPB with TQLB with Shamrock approach. We aim to assess the anesthetic efficacy of this combination technique and expect it will be an ideal alternative for conventional LPBs in THA. METHODS AND ANALYSIS: In this prospective randomized controlled trial, 84 patients schedule for THA will be enrolled. The patients will be randomly assigned at a 1:1:1 ratio to receive LPB at L3 level (P group), T12 paravertebral block combined with LPB at L3 and L4 levels (TP group), or LPB combined with TQLB at L3 level (PQ group). Each method will be evaluated in terms of the successful rate of sensory blockade, postoperative pain, performance time of block, requirement for intraoperative sufentanil, cumulative doses of intraoperative vasoactive medications, and adverse events. ETHICS AND DISSEMINATION: The study protocol has been approved by the institutional review board (IRB) at Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, China (No.2020–031). The results will be disseminated in a peer-reviewed journal and the ClinicalTrials.gov registry. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04266236. Registered on 10 February 2020. ClinicalTrials.gov PRS: Record Summary NCT04266236. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-023-07619-z.