Comparison of the effects of ultrasound-guided quadratus lumborum block and erector spinae plane block on postoperative pain in abdominal surgeries: a protocol for systematic review and meta-analysis.

INTRODUCTION: Ultrasound-guided quadratus lumborum block and erector spinae plane block are widely used for postoperative analgesia in adult patients undergoing abdominal surgeries. This protocol aims to compare the analgesic effects between ultrasound-guided quadratus lumborum block and erector spinae plane block on postoperative pain in abdominal surgeries.

METHODS AND ANALYSIS: Four databases, including PubMed, EMBASE, Web of Science and the Cochrane Central Register of Controlled Trials (CENTRAL), will be searched. Randomised controlled trials that compared the analgesic effects between ultrasound-guided quadratus lumborum block and erector spinae plane block on postoperative pain in adult patients will be identified. The primary outcomes are time to the first analgesic request and postoperative analgesic consumption over 24 hours. Secondary outcomes will include postoperative pain scores and the incidence of side effects. RevMan V.5.3 software will be used for data processing and statistical analysis. The Grading of Recommendation, Assessment, Development and Evaluation approach will be used to assess the evidence quality of outcomes.

ETHICS AND DISSEMINATION: Ethical approval is not required for this study. Results of this present study will be submitted to a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER: CRD42023445802.