Analgesic Efficacy and Outcomes of Ultrasound-guided Erector Spinae Plane Block in Patients Undergoing Bariatric and Metabolic Surgeries: A Systematic Review

Erector spinae plane block (ESPB) has been used as an intervention for providing postoperative analgesia in patients undergoing bariatric and metabolic surgeries. After registering the protocol in PROSPERO, randomized controlled trials and nonrandomized observational studies were searched in various databases till July 2022. The primary outcome was 24-h opioid consumption; the secondary outcomes were intraoperative opioid use, pain scores, time to rescue analgesia, and complications. The risk of bias and Newcastle-Ottawa scale were used to assess the quality of evidence. From the 695 studies identified, 6 studies were selected for analysis. The 24-h opioid consumption was significantly lesser in ESPB group when compared to control (mean difference [MD]: −10.67; 95% confidence interval [CI]: −21.03, −0.31, I² = 99%). The intraoperative opioid consumption was significantly less in the ESPB group (MD: −17.75; 95% CI: −20.36, −15.13, I² = 31%). The time to rescue analgesia was significantly more in the ESPB group (MD: 114.36; CI: 90.42, 138.30, I² = 99%). Although pain scores were significantly less at 6 and 24 h in ESPB group (MD: −2.00, 95% CI: −2.49, −1.51; I² = 0% and MD: −0.48; 95% CI: −0.72, −0.24; I² = 48%), at zero and 12 h, the pain scores were comparable (MD: −1.53, 95% CI: −3.06, −0.00, I² = 97% and MD: −0.80; 95% CI: −1.80, 0.20, I² = 88%). Bilateral ESPB provides opioid-sparing analgesia and better pain scores when compared to control. These results should be interpreted with caution due to high heterogeneity among the included studies.