Effect of intravenous lidocaine infusion on postoperative pulmonary complications in patients undergoing minimally invasive esophagectomy: a study protocol of double-center, double-blind, randomized controlled trial.	INTRODUCTION: Esophageal cancer is the eighth most prevalent malignant tumor in the world and has the sixth highest mortality rate. Postoperative pulmonary complications (PPCs) are one of the most common complications of minimally invasive esophagectomy (MIE). The non-local anesthetic effects of lidocaine have been widely reported, but only a few studies have focused on its effects on lung protection in MIE. This study is designed to test the hypothesis that intraoperative intravenous lidocaine infusion can reduce the incidence of PPCs in patients undergoing MIE. METHODS AND ANALYSIS: In this double-center, randomized, double-blind, placebo-controlled superiority trial, 770 participants from three centers will be randomly assigned to two groups, namely the lidocaine group and the placebo group in a 1:1 ratio. The primary outcome is the incidence of PPCs within 7 days following surgery. The secondary outcomes include the incidence of (1) respiratory infection; (2) respiratory failure; (3) pneumothorax; (4) atelectasis; (5) pleural effusion; (6) bronchospasm; (7) aspiration pneumonitis; (8) anastomotic fistula; (9) moderate to severe pain within 24 and 48 h at rest and when coughing; (10) additional rescue analgesics use. DISCUSSION: This study aims to address a significant gap in the prevention of PPCs in patients undergoing MIE for esophageal cancer. PPCs are common and can negatively impact recovery and survival outcomes, making effective prevention strategies crucial. While lidocaine's non-local anesthetic properties, including anti-inflammatory and analgesic effects, have been well-documented, few studies have focused on its role in lung protection during MIE. By assessing the incidence of PPCs and other secondary outcomes, this trial seeks to determine whether intraoperative lidocaine infusion can offer a novel, non-invasive approach to reducing PPC risk and improving overall postoperative recovery. If lidocaine proves effective, this study will provide a new way to improve patient outcomes, particularly for those with high PPCs risk. Furthermore, the results could expand the scope of lidocaine use in surgical settings, suggesting a potentially low-cost and accessible intervention for broader perioperative lung protection. TRIAL REGISTRATION NUMBERS: NCT06138041 (ClinicalTrials.gov, registration date: 2024-10-22). STRENGTHS AND LIMITATIONS OF THE STUDY: This study will provide a reliable conclusion investigating the effect of intraoperative intravenous lidocaine infusion on postoperative pulmonary complications in patients undergoing minimally invasive esophagectomy. The study includes an appropriate sample size and a double-center, randomized, and double-blind placebo-controlled design, which reduces potential bias. The full analysis set consists of all participants according to the intention-to-treat principle and the per-protocol set will be both performed. Per-protocol analysis will be used for sensitivity analyses. Intravenous lidocaine infusion is only continued until patients are transferred out of the post-anesthesia care unit, while the benefit of prolonged infusion in the ward will not be investigated.	esophagus