Peripheral Nerve Blocks Modulate the Pain-Mood Relationship in Bariatric Surgery: A Secondary Analysis of a Randomized, Controlled Trial.

OBJECTIVE: To determine whether adding peripheral nerve blocks (transversus abdominis plane block [TAPB] or quadratus lumborum block [QLB]) to general anesthesia (GA) was associated with improved postoperative anxiety and depressive symptoms in patients with morbid obesity undergoing laparoscopic sleeve gastrectomy (LSG). METHODS: In this secondary analysis of a single-center, randomized, double-blind clinical trial (N = 225), morbidly obese patients scheduled for LSG were randomized to receive either bilateral, ultrasound-guided transversus abdominis plane block (TAPB) or quadratus lumborum block (QLB) with 0.33% ropivacaine and dexmedetomidine (1 µg/kg) before general anesthesia (GA) or general anesthesia alone. Psychological symptoms (depression and anxiety) were assessed using the Hamilton Depression and Anxiety Scale at baseline, and at 1 and 3 months postoperatively. RESULTS: All three groups achieved significant and comparable ideal body weight loss, and overall improvements in psychological symptoms. Overall, depression symptoms decreased from 71.1% to 46.7% and anxiety from 72.4% to 48.9% at postoperative 3 months. Psychological improvement trajectories varied between groups. Relative to the GA reference group, the QLB group exhibited significantly larger declines in HAMD scores (β = -1.81, 95% CI: -2.76 to -0.87, P < 0.001) and HAMA scores (β = -1.83, 95% CI: -2.94 to -0.72, P = 0.001). QLB also performed a stronger reduction in anxiety than the TAPB group (P = 0.015). Visceral pain scores were higher in those with greater anxiety 1 and 3 months after surgery. CONCLUSION: PNBs combined with general anesthesia reduced anxiety and depression 3 months after LSG. The correlation between visceral pain and anxiety suggests that improved analgesia may contribute to these psychological benefits.