Single injection Quadratus Lumborum block for postoperative analgesia in adult surgical population: A systematic review and meta-analysis

Abstract Study objective The Quadratus lumborum (QL) block was first reported as a postoperative analgesic technique for abdominoplasty, and since has been used for a variety of surgeries. In this systematic review and meta-analysis, we summarize the current literature on the postoperative analgesic effect of QL block. Design We systematically searched PubMed, CENTRAL, CINAHL, EMBASE, Clinical Trials Registry (U.S. National Library of Medicine), Web of Science and Google Scholar for randomized control trials. The primary outcome was the comparison of 24-hour opioid requirements between the QL block and systemic analgesia cohorts; secondary outcomes included time to rescue analgesia, postoperative nausea and vomiting, block related complications and comparison between QLB and other regional anesthesia techniques. Main results We identified 22 studies for inclusion: 16 studies compared QL block to GA with systemic analgesia, four studies compared the QL block with the TAP block, and the rest on other comparisons (such as femoral block and continuous wound infiltration). QL block significantly reduced the opioid requirement in cesarean deliveries and renal surgeries, there were insufficient studies for the other surgery types. Several studies reported that QLB was associated with significantly reduced pain for up to 24 h postoperatively, but quantitative analysis is not possible due to high heterogeneity. The most common block related complication was local anesthetic toxicity. Conclusions QL block significantly reduces opioid requirement in cesarean delivery and in renal surgery. The evidence for other surgery types are limited. QL block may have analgesic effect for up to 24 h postoperatively, but the evidence is again limited. There is currently limited evidence comparing QL block to other analgesic techniques, further studies are needed in this area.