Single-Shot Regional Anesthesia for Bariatric Surgery: a Systematic Review and Network Meta-Analysis

Purpose: Laparoscopic bariatric surgeries can cause intense postoperative pain. Opioid medication can alleviate the pain but can have harmful side effects especially in patients with obstructive sleep apnea. To promote early recovery, enhanced recovery after surgery guideline advises minimizing opioid use and opting for alternative analgesics. This paper aims to investigate the effect of regional anesthesia techniques through a systematic review and network meta-analysis. Primary outcome is postoperative morphine equivalent consumption at 24 h. Methods: Search was conducted in the following databases: PubMed, CENTRAL, Scopus, and EMBASE, from the inception until 10 January 2023. The eligibility criteria were determined by PICOS, including postoperative opioid consumption, pain scores, time to ambulate, use of additional analgesics, and adverse events. The quality assessment was performed using the Risk of Bias 2 Tool, and the certainty of evidence was assessed using the GRADE approach. Funnel plots were used to evaluate publication bias. Results: We included 22 studies in quantitative synthesis. A review of 12 studies found that all techniques had a lower mean consumption of opioids compared to placebo or no intervention, with TAP block having the greatest reduction. The quality of evidence for postoperative pain, PONV, time to deambulate, and use of rescue analgesics, was rated as moderate, with TAP block being the most effective intervention. There was no publication bias in any outcome. Conclusions: TAP block is superior to other regional anesthesia techniques in reducing opioid consumption, pain, PONV, and use of rescue analgesics in bariatric surgery. However, further research is needed.