Effect of esketamine on inflammatory factors in opioid-free anesthesia based on quadratus lumborum block: A randomized trial

Background: As strong analgesics, opioids provide the analgesic component of general anesthesia, but they have bidirectional effects on the immune system, promoting the production of pro-inflammatory factors. The idea of opioid-free anesthesia is to replace the analgesic effect of opioids in the treatment of acute pain with comparably effective drugs that do not affect the immune system and thereby decrease the production of inflammatory factors. Therefore, this study aims to observe the effect of opioid-free esketamine anesthesia based on quadratus lumborum block on inflammatory factors in patients undergoing lower abdominal or pelvic surgery. Methods: A total of 122 patients who underwent lower abdominal or pelvic surgery in our hospital from March 2021 to June 2022 were selected and divided into the esketamine (E) group (n = 62) and control (C) group (n = 60) according to the random number table method. According to the surgical field, the 2 groups underwent unilateral/bilateral quadratus lumborum block in the supine position under ultrasound guidance. In addition, both groups received a target controlled infusion of propofol 3 to 3.5 mu g/mL and intravenous rocuronium 0.8 mg/kg. Group E was given opioid-free anesthesia, group C was given opioid-based anesthesia. A 3 to 5 laryngeal mask was inserted according to body weight, and rocuronium 0.5 mg/kg was added intermittently. The levels of interleukin-6 (IL-6), interleukin-8 (IL-8), C-reactive protein (CRP), procalcitonin, tumor necrosis factor-alpha (TNF-alpha), numeric rating scales, dosage of propofol, dexmedetomidine and rocuronium, as well as the numeric rating scales score and analgesic complications were monitored in the 2 groups. Results: There was no significant differences in general outcomes between the 2 groups (P > .05). The blood pressure in group E was higher than in group C at T1 (P < .05). The levels of IL-6, TNF-alpha, CRP and IL-8 in group E were significantly lower than in group C at T1, T2, T3, and T4 (P < .05). The levels of IL-6, TNF-alpha, procalcitonin, CRP and IL-8 in the 2 groups at T1, T2, T3, and T4 were significantly higher than at T0 (P < .05). Conclusion: Opioid-free esketamine anesthesia based on quadratus lumborum block achieved perfect postoperative analgesia with little effect on inflammatory factors in patients undergoing lower abdominal or pelvic surgery.