Effect of opioid-free anesthesia based on ultrasound-guided anterior quadratus lumborum block on postoperative inflammatory factors in patients undergoing lower abdominal and pelvic surgery: a randomized controlled trial

Abstract Objective This retrospective, randomized, controlled trial was conducted to investigate the effect of opioid-free anesthesia based on ultrasound-guided anterior quadratus lumborum block on postoperative inflammatory factors in patients undergoing lower abdominal or pelvic surgery. Methods From January 2023 to September 2024, a total of 91 patients who underwent lower abdominal or pelvic surgery in our hospital were selected and divided into a quadratus lumborum block group (Q) and a control group (C) using the random number table method. In Group Q, opioid-free anesthesia based on quadratus lumborum block was employed, and 0.20% ropivacaine was administered for the quadratus lumborum block. Group C received opioid anesthesia with a mock-procedure mimicking quadratus lumborum block using a placebo. The levels of IL-6, CRP, PCT, and TNF-α, NRS score, amount of blood loss, as well as the doses of propofol, dexmedetomidine, dexamethasone, and rocuronium were monitored in both groups. Results There was no significant difference in the preoperative NRS score between the two groups ( P > 0.05). The NRS scores of group Q at t1, t2, t3, and t4 were lower than those of group C, and the difference was statistically significant ( P < 0.05). Within-group comparisons showed that the NRS scores of group Q at t1, t3, and t4 were not significantly different ( P > 0.05). There were no significant differences in the levels of IL-6, CRP, PCT, and TNF-α between the two groups at T0 ( P > 0.05). The levels of IL-6 and CRP in group Q were significantly lower than in group C at T1, T2, T3, and T4 ( P < 0.05). Intragroup comparisons indicated that there was no significant difference in CRP levels between T2 and T5 in group Q ( P > 0.05). The levels of TNF-α in group Q were significantly lower than in group C at T1, T2, and T3 ( P < 0.05). There was no significant difference in PCT values between the two groups at any time point ( P > 0.05). Conclusion Opioid-free anesthesia based on ultrasound-guided anterior quadratus lumborum block was associated with lower levels of postoperative inflammatory biomarkers in patients undergoing lower abdominal or pelvic surgery. The clinical significance of these findings warrants further investigation. Trial registration : Patient enrollment for this trial started in January 2023.The trial was retrospectively registered with the Chinese Clinical Trial Registry ( www.chictr.org.cn , ChiCTR2300072842) on June 26, 2023.