Optimal approach for ultrasound-guided transversus abdominis plane (TAP) blocks for abdominal surgeries: a protocol for systematic review and meta-analysis.

INTRODUCTION: Transversus abdominis plane (TAP) blocks are commonly used for postoperative analgesia after various abdominal surgeries. There are several different approaches for performing TAP blocks, mainly including posterior, lateral and subcostal approaches. An increasing number of randomised controlled trials (RCTs) have compared the analgesic effects of different TAP block approaches, but the results have not been consistent. This protocol aims to determine the optimal approach of ultrasound-guided TAP blocks for postoperative analgesia after abdominal surgery.

METHODS AND ANALYSIS: Four databases, including Web of Science, PubMed, EMBASE and the Cochrane Library will be systematically searched to identify RCTs that compared the analgesic effects of different ultrasound-guided TAP block approaches. The search interval will range from the inception of the databases to 30 July 2024. The postoperative opioid consumption over 24 hours will be defined as the primary outcome. The secondary outcomes will include the analgesia duration, postoperative pain scores at rest and during movement at different timepoints and the incidence of adverse effects. All the statistical analyses will be conducted using RevMan V.5.4. The quality of evidence will be evaluated by the Grading of Recommendations Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION: Ethical approval will not be needed. The results will be submitted to one peer-reviewed journal when completed.

PROSPERO REGISTRATION NUMBER: CRD42024510141.