Safety and effectiveness of multimodal opioid-free anaesthesia for pain and recovery after laparoscopic surgery: a systematic review and meta-analysis

Objectives This study aimed to investigate the safety and effectiveness of opioid-free anaesthesia (OFA) versus conventional opioid anaesthesia (OA) for postoperative pain management and recovery in patients undergoing laparoscopic surgery. Design Systematic review and meta-analysis. Data sources The databases of PubMed, Embase, Cochrane Library and Web of Science were searched from inception to August 2023. Eligibility criteria for selecting studies We included any randomised controlled trial comparing OFA (at least two drugs or two more alternatives to opioids) with OA for laparoscopic surgery. The primary outcomes included postoperative pain scores, measured on a Numerical Rating Scale or Visual Analogue Scale ranging from 0 to 10, at 0-2 hours and 24 hours postoperatively; postoperative analgesic consumption, measured in morphine equivalent doses (mg); and quality of recovery, assessed using the QoR-40 score (ranging from 40 to 200). The secondary outcomes included the incidence of postoperative nausea and vomiting (PONV), antiemetic use, extubation time (measured in minutes), post-anaesthesia care unit discharge time (measured in minutes), shivering, bradycardia, hypotension and pruritus. Data extraction and synthesis Meta-analyses were performed using Stata16 software, using the DerSimonian and Laird's method and inverse variance to summarise effect sizes for each outcome under a random effects model for all outcomes. Outcomes were reported as OR for binary outcome indicators and mean difference (MD) for continuous outcome indicators, with corresponding 95% CIs. I-2 coefficients were used to assess high, medium and low heterogeneity. RoB was used to assess the risk of bias of the included studies. GRADE assessed the certainty of the evidence using a systematic framework for rating the quality of evidence and strength of recommendations. Results Ultimately, 12 studies involving 983 patients undergoing laparoscopic surgery were included in this systematic evaluation and meta-analysis. The results of the meta-analysis showed an association of OFA with reduced early postoperative 0-2-hour pain response (MD -1.29; 95% CI -2.23 to -0.36; I-2=92%; p<0.001) and the consumption of analgesics (MD -0.43; 95% CI -0.60 to -0.26; I-2=1.8%; p=0.405) in patients undergoing laparoscopic compared with OA. The results of the meta-analysis suggest that OFA could improve the quality of early postoperative recovery (MD 1.37; 95% CI 0.36 to 2.39; I-2=94.2%; p<0.001) and reduce the incidence of PONV (OR 0.38; 95% CI 0.24 to -0.59; I-2=37.6%; p=0.108) and antiemetics (MD 0.29; 95% CI 0.14 to 0.61; I-2 = 0%; p=0.473) in patients. The other variables presented no significant differences between the groups. Results Ultimately, 12 studies involving 983 patients undergoing laparoscopic surgery were included in this systematic evaluation and meta-analysis. The results of the meta-analysis showed an association of OFA with reduced early postoperative 0-2-hour pain response (MD -1.29; 95% CI -2.23 to -0.36; I-2=92%; p<0.001) and the consumption of analgesics (MD -0.43; 95% CI -0.60 to -0.26; I-2=1.8%; p=0.405) in patients undergoing laparoscopic compared with OA. The results of the meta-analysis suggest that OFA could improve the quality of early postoperative recovery (MD 1.37; 95% CI 0.36 to 2.39; I-2=94.2%; p<0.001) and reduce the incidence of PONV (OR 0.38; 95% CI 0.24 to -0.59; I-2=37.6%; p=0.108) and antiemetics (MD 0.29; 95% CI 0.14 to 0. 61; I-2 = 0%; p=0.473) in patients. The other variables presented no significant differences between the groups. Conclusions OFA may be more beneficial for postoperative pain management and recovery in patients undergoing laparoscopic surgery compared with conventional OA. Future studies could further extend these findings to other surgical populations.