Single-injection regional analgesia techniques for mastectomy surgery: A network meta-analysis

BACKGROUND Patients undergoing mastectomy surgery experience severe postoperative pain. Several regional techniques have been developed to reduce pain intensity but it is unclear, which of these techniques is most effective. OBJECTIVES To synthesise direct and indirect comparisons for the relative efficacy of different regional and local analgesia techniques in the setting of unilateral mastectomy. Postoperative opioid consumption at 24 h, postoperative pain at extubation, 1, 12 and 24 h, postoperative nausea and vomiting were collected. DESIGN Systematic review with network meta-analysis (PROSPERO:CRD42021250651). DATA SOURCE PubMed, Scopus, the Cochrane Central Register of Controlled Trials (from inception until 7 July 2021). ELIGIBILITY CRITERIA All randomised controlled trials investigating single-injection regional and local analgesia techniques in adult patients undergoing unilateral mastectomy were included in our study without any language or publication date restriction. RESULTS Sixty-two included studies randomising 4074 patients and investigating nine techniques entered the analysis. All techniques were associated with less opioid consumption compared with controls The greatest mean difference [95% confidence interval (CI)] was associated with deep serratus anterior plane block: mean difference -16.1 mg (95% CI, -20.7 to -11.6). The greatest reduction in pain score was associated with the interpectoral-pecto-serratus plane block (mean difference -1.3, 95% CI, -1.6 to - 1) at 12 h postoperatively, and with superficial serratus anterior plane block (mean difference -1.4, 95% CI, -2.4 to -0.5) at 24 h. Interpectoral-pectoserratus plane block resulted in the greatest statistically significant reduction in postoperative nausea/vomiting when compared with placebo/no intervention with an OR of 0.23 (95% CI, 0.13 to 0.40). CONCLUSION All techniques were associated with superior analgesia and less opioid consumption compared with controls. No single technique was identified as superior to others. In comparison, local anaesthetic infiltration does not offer advantages over multimodal analgesia alone.