Opioid‐free vs. opioid‐inclusive anaesthesia with or without regional anaesthesia for postoperative pain: a systematic review with network meta‐analysis of randomised controlled trials
C. L. de Carvalho, Kariem El‐Boghdadly, Idrys H. L. Guedes, Maria Vitória M. Dantas, Danusa P. B. Tomé, Isabella Beserra Ramos, Clarissa S. H. Gomes, Guilherme K. P. A. Alves, Arthur P. Bezerra, Jayme M. Santos Neto, J. J. Pandit, Leandro G. Braz
Abstract
INTRODUCTION: Concerns about opioid-related adverse effects have increased interest in opioid-free anaesthesia, but the benefits compared with opioid-inclusive techniques, especially in the presence of regional anaesthesia, remain uncertain. METHODS: We undertook a systematic review with a network meta-analysis of randomised controlled trials comparing six strategies in adults: opioid-free anaesthesia and opioid-inclusive anaesthesia using remifentanil alone or other opioids, each with or without regional anaesthesia. Primary outcome was postoperative pain. Secondary outcomes were: postoperative opioid use; post-anaesthesia care unit discharge time; hospital duration of stay; and incidence of complications. RESULTS: We included 885 trials from 59 countries. Techniques incorporating regional anaesthesia consistently ranked highest for postoperative pain. Regional anaesthesia combined with an opioid-free intra-operative strategy achieved some of the highest surface under the cumulative ranking curve values for pain at 2 h, 12 h and 48 h (93%, 85% and 75%, all low certainty). When regional anaesthesia was used, differences between opioid-free and opioid-inclusive techniques were minimal (moderate certainty). For opioid consumption, regional anaesthesia with an opioid-free strategy ranked best at 2 h (moderate certainty), 12 h (low certainty) and 48 h (low certainty), with surface under the cumulative ranking curve values > 98%. Techniques without regional anaesthesia were associated with higher pain scores and greater opioid requirements. Opioid-free approaches, especially when combined with regional techniques, were associated with lower rates of postoperative nausea and vomiting. DISCUSSION: Regional anaesthesia was the key determinant of improved postoperative pain control, and intra-operative opioids added little additional benefit when regional techniques provided adequate coverage. Without regional anaesthesia, neither opioid-free nor opioid-inclusive strategies showed consistent analgesic superiority. However, opioid-free techniques reduced postoperative nausea and vomiting. These findings support preferential use of regional anaesthesia where feasible and suggest that avoiding intra-operative opioids may facilitate recovery, particularly when regional techniques are employed effectively.