Effect of Anterior Quadratus Lumborum Block at the Lateral Supra-Arcuate Ligament Combined with Esketamine on the Quality of Postoperative Recovery After Laparoscopic Radical Surgery for Elderly Patients with Colorectal Cancer: A Randomized Controlled Trial.

Abstract

Postoperative pain, opioid exposure and slow recovery remain common concerns in elderly patients undergoing laparoscopic radical resection of colorectal cancer. We assessed whether anterior quadratus lumborum block at the lateral supra-arcuate ligament (QLB-LSAL) combined with low-dose esketamine improves recovery quality. In this single-centre, randomized, placebo-controlled trial with blinded outcome assessment, 90 patients aged ≥60 years were assigned to QLB-LSAL with a saline infusion (Group Q), esketamine alone (Group E), or QLB-LSAL with esketamine (Group QE). The prespecified primary endpoint was the QoR-40 total score on postoperative day 3. Esketamine 0.2 mg/kg was given intravenously before induction, followed by 0.2 mg/kg/h until 30 min before the end of surgery in Groups E and QE; Group Q received an equal volume of saline. Longitudinal data were analysed with linear mixed-effects models, with Tukey post-hoc testing and Benjamini-Hochberg correction. Eighty-eight patients were analysed (Q=29, E=30, QE=29). On day 3 the QoR-40 total score was higher in Group QE than in Group E (adjusted difference 8.30, 95% CI 4.37-12.23, Tukey P<0.001); the corresponding day-1 difference was 12.07 (95% CI 7.66-16.47, P<0.001). Group QE also showed better comfort and pain scores, lower remifentanil consumption and fewer day-1 pump activations than Group E, and a higher day-1 QoR-40 score than Group Q (P=0.006). Between-group differences in HADS anxiety scores were not significant after adjustment for multiplicity (QE vs Q on day 1, P=0.068). The incidence of adverse events did not differ between groups. In elderly patients undergoing laparoscopic colorectal cancer surgery, QLB-LSAL combined with low-dose esketamine improved the prespecified day-3 recovery endpoint and reduced early postoperative pain and opioid use compared with esketamine alone; any anxiolytic effect was not confirmed after multiplicity adjustment. Trial registration: ChiCTR2400082301.