Intraoperative autonomic neural blockade: comparison between different local anesthetics combinations: a randomized clinical trial

Abstract

Background: Advances in minimally invasive techniques, enhanced recovery protocols, and regional pain management have improved postoperative outcomes. However, visceral pain and postoperative nausea and vomiting (PONV) remain challenging, particularly after laparoscopic sleeve gastrectomy (LSG) and other minimally invasive procedures. Intraoperative autonomic neural blockade (ANB) has demonstrated efficacy in addressing these issues, with the duration of the effect its most important limitation.

Methods: This randomized clinical trial (RCT) evaluated the effectiveness of three anesthetic combinations used during ANB for LSG. The combinations were Bupivacaine + Clonidine (B + C), Bupivacaine + Dexamethasone (B + D), and Bupivacaine + Dexamethasone + Gelofusine (B + D + G). 160 patients were randomly assigned to one of the three groups. Pain levels, PONV, and the need for additional analgesics were assessed at 1, 8, 24, and 36 h postoperatively.

Results: There was no statistical difference among the groups with low pain levels, PONV, and analgesic consumption across all anesthetic combinations. No complications were reported. Opioid consumption was lower in all three combinations than in our index study using only 0.5% bupivacaine. Pain levels peaked at 24 h and decreased significantly by 36 h, especially in the B + D + G group. The B + D + G group achieved the highest percentage of "perfect result" patients, with no pain, no PONV, and no need for additional analgesics.

Conclusions: This study demonstrates the safety and efficacy of intraoperative ANB using different anesthetic combinations in LSG patients without statistical significance among the groups. The B + D + G group achieved the lowest 36-h pain levels and the highest percentage of "perfect results," although the clinical relevance is tentative. The progressive reduction in opioid use highlights ANB's role in improving patient safety. The findings may inform adjustments to enhanced recovery after surgery (ERAS) protocols and support integrating ANB into clinical practice to improve postoperative outcomes in LSG patients.

Trial registration: The protocol was registered in ClinicalTrials.gov under the identifier NCT06137924.

Keywords: Autonomic neural blockade; Local anesthetics; Opioids; Postoperative nausea and vomiting; Visceral pain.