Postoperative Analgesic Effects of Serratus Anterior Plane Block for Thoracic and Breast Surgery: A Meta-analysis of Randomized Controlled Trials

Postoperative pain is a concern after thoracic and breast surgeries. Recent studies have demonstrated that ultrasound-guided serratus anterior plane block (SAPB) could provide postoperative analgesia. The objective of this systematic review and meta-analysis was to examine the effects of SAPB on postoperative analgesia in thoracic and breast surgery. A systematic review and meta-analysis of randomized control trials (RCTs). We systematically queried the PubMed, Embase, Web of Science, and Cochrane Library online databases from their establishment through Mar 31, 2022. Eligible RCTs were selected for the purpose of conducting the meta-analysis. The risk of bias of the included trials was assessed by Cochrane Review Manager. The level of certainty was examined utilizing the GRADE (Grade of Recommendations Assessment, Development, and Evaluation) scale to determine whether the evidence was of high quality or not. During the process of the meta-analysis, a total of 27 pieces of literature was included in the present research. SAPB significantly reduced the intraoperative opioid consumption (mean difference [MD] = -9.52 mg of morphine equivalent, 95% CI, -15.50 to -3.54; P < 0.01, I2 = 98%) and postoperative pain opioid consumption (MD = -23.12 mg of morphine equivalent, 95% CI, -30.59 to -15.65; P < 0.01, I2 = 100%. Also, patients in the SAPB group had lower pain scores during the first postoperative 24 hours. Furthermore, SAPB attenuated the occurrence of postsurgical nausea and vomiting, as well as chronic postsurgical pain. Double-blinding was not performed in some trials, also some assessors were not blinded; the included sample sizes of eligible trials which reported the incidence of chronic postsurgical pain were relatively small; the comparisons between SAPB and other types of blocks were not performed in our meta-analysis. Our findings suggest that SAPB not only relieves acute pain after thoracic and breast surgery, but also reduces the incidence of chronic postsurgical pain.