The effect of preoperative stellate ganglion block on postoperative delirium in elderly patients undergoing gastrointestinal oncologic surgery: protocol for a randomized, double-blind, sham-controlled trial.

BACKGROUND

Postoperative delirium (POD) is a common and severe complication in elderly patients following gastrointestinal oncologic surgery, associated with prolonged hospitalization, increased morbidity and mortality, and substantial healthcare costs. The stellate ganglion block (SGB), a sympathetic nerve block with anti-inflammatory and autonomic-modulating effects, has shown promise in improving perioperative outcomes. However, high-quality randomized controlled trials evaluating its efficacy in preventing POD in this older population are lacking.

METHODS

This is a single-center, prospective, randomized, double-blind (participants and outcome assessors), sham- controlled trial. A total of 174 elderly patients (≥60 years) scheduled for elective radical gastrointestinal cancer surgery will be randomized in a 1:1 ratio to receive either two ultrasound-guided SGBs (one on the afternoon before surgery and one 30 min before anesthesia induction) with 0.375% ropivacaine (3-5 mL each) or a sham block with normal saline (3-5 mL). All patients, surgeons, and outcome assessors will be blinded to group assignment. A standardized anesthesia protocol and a multicomponent delirium- prevention bundle will be applied to all participants. The primary outcome is the cumulative incidence of POD within postoperative days 1-3, assessed twice daily using the 3-Minute Diagnostic Interview for CAM-defined Delirium (3D-CAM). Secondary outcomes include delirium severity and duration, postoperative recovery (Quality of Recovery-15 score), inflammatory biomarkers (procalcitonin, C-reactive protein (CRP), interleukin-6 (IL-6), lymphocyte-to-monocyte ratio [LMR], neutrophil-to-lymphocyte ratio [NLR]), pain trajectories, opioid consumption, and length of hospital stay.

EXPECTED OUTCOMES: We hypothesize that preoperative SGB will reduce the incidence and severity of POD compared to a sham block. This study will provide preliminary evidence on the feasibility and efficacy of SGB as a targeted intervention for high-risk older surgical oncology patients, while acknowledging that the assumed effect size may be optimistic.

CLINICAL TRIAL REGISTRATION: https://www.chictr.org.cn/showproj.html?proj=302103, identifier: ChiCTR2600118223.