Opioid Free Anesthesia in Thoracic Surgery: A Systematic Review and Meta Analysis

Introduction: Recent studies showed that balanced opioid-free anesthesia is feasible and desirable in several surgical settings. However, in thoracic surgery, scientific evidence is still lacking. Thus, we conducted the first systematic review and meta-analysis of opioid-free anesthesia in this field. Methods: The primary outcome was the occurrence of any complication. Secondary outcomes were the length of hospital stay, recovery room length of stay, postoperative pain at 24 and 48 h, and morphine equivalent consumption at 48 h. Results: Out of 375 potentially relevant articles, 6 studies (1 randomized controlled trial and 5 observational cohort studies) counting a total of 904 patients were included. Opioid-free anesthesia compared to opioid-based anesthesia, was associated with a lower rate of any complication (74 of 175 [42%] vs. 200 of 294 [68%]; RR = 0.76; 95% CI, 0.65-0.89; p < 0.001; I-2 = 0%), lower 48 h morphine equivalent consumption (MD -14.5 [-29.17/-0.22]; p = 0.05; I-2 = 95%) and lower pain at 48 h (MD -1.95 [-3.6/0.3]; p = 0.02, I = 98%). Conclusions: Opioid-free anesthesia in thoracic surgery is associated with lower postoperative complications, and less opioid demand with better postoperative analgesia at 48 h compared to opioid-based anesthesia.