Effect of liposomal bupivacaine on opioid requirements and length of stay in colorectal enhanced recovery pathways: a systematic review and network meta-analysis.

BACKGROUND Reducing postoperative opioid consumption is a key aim of enhanced recovery after colorectal surgery protocols. Potential solutions include anaesthetic techniques such as local infiltration of anaesthetic agents or transverses abdominis plane (TAP) blocks. This study aimed to assess the efficacy of liposomal bupivacaine for colorectal resections, across a variety of anaesthetic techniques. METHODS PubMed, Scopus and EMBASE databases were searched for relevant studies assessing liposomal bupivacaine (LB), administered by any anaesthetic technique. The primary outcome was postoperative morphine consumed (milligrams) and the secondary outcome was length of stay (LOS, days).A Bayesian network meta-analysis comparing LB versus non-LB analgesia was performed alongside meta-regression for different surgical approaches. RESULTS Twelve trials were included, with a total of 2,512 patients. LB-based wound infiltration was most likely to reduce LOS followed by TAP block with LB (SUCRA 85.55 and 70.26, respectively). TAP block with LB was most likely to reduce morphine requirements, followed by wound infiltration with LB (SUCRA 83.94 and 75.73, respectively). Compared to standard analgesia, LB-based wound infiltration reduced morphine usage (MD 36.64 mg, 95% CrI= 15.64 to 59.20) and length of stay (MD 1.79 days, 95% CrI= 0.59 to 3.81). On meta-regression, the findings held for minimally invasive surgery only. CONCLUSION Although LB-based interventions were associated with reduced postoperative morphine requirements and length of stay in this network meta-analysis, the confidence in these estimates was graded as very low. Further well-executed trials are required before LB can be recommended as a first-line agent.