198 Fascial plane blocks in total abdominal hysterectomy: a systematic review and network meta-analysis

Background and Aims Fascial plane blocks can provide effective analgesia for abdominal surgeries. However, different randomized controlled trials (RCTs) showed controversial results in total abdominal hysterectomy and there were limited data directly comparing the techniques. We conducted a network meta-analysis of RCTs to investigate the effectiveness of transversus abdominis plane (TAP) block, quadratus lumborum (QL) block and erector spine plane (ESP) block in patients with total abdominal hysterectomy. Methods We searched PubMed, Embase, Cochrane Library, and CINAHL from inception to June 2021. Random-effects network meta-analyses were performed for comparing the fascial plane blocks. The primary outcome was 24 hours morphine equivalent consumption and the secondary outcome included time to first rescue analgesia, pain scores and rates of nausea and vomiting. Results Eighteen studies were included in the current meta-analysis. Quality assessment revealed that only 11 of 18 RCTs had some concerns regarding overall risk of bias. The results showed quadratus lumborum block was the best intervention for morphine consumption reduction at 24 h and resting pain scores. Transversus abdominis plane block was also effective in reducing opiate consumption and resting pain scores. However, no techniques were associated with a reduced incidence of postoperative nausea and vomiting. TAP block subgroup analyses revealed that location and timing of plane block may impact the effectiveness of 24 h opioid consumption reduction. Conclusions Fascial plane blocks are effective analgesic techniques in total abdominal hysterectomy. However, there are insufficient data for to draw definitive conclusions, further studies are required for QL and ESP blocks.