Abstract
BACKGROUND AND PURPOSE: While intravenous lidocaine reduces propofol requirements during procedures, its effects on postoperative cognitive function remain uncertain. This study evaluated whether lidocaine enhances cognitive recovery in patients undergoing endoscopic submucosal dissection (ESD) with propofol sedation. PATIENTS AND METHODS: In this randomized, double-blind, placebo-controlled trial, 234 patients undergoing colorectal ESD received either intravenous lidocaine (1.5 mg/kg bolus followed by 2 mg/kg/h infusion) or a saline placebo. The standard sedation protocol included sufentanil 0.1 μg/kg and propofol for induction, with additional propofol as needed to maintain adequate sedation depth. The primary outcome was cognitive recovery on postoperative day 3 assessed by the PostopQRS cognitive domain. Secondary outcomes included recovery patterns at four timepoints (30 minutes, 1, 3, and 7 days), propofol consumption, injection pain, satisfaction scores, and adverse events. RESULTS: The lidocaine group demonstrated significantly better cognitive recovery than the placebo group [relative risk 1.15, 95% confidence interval (CI) 1.04-1.28, p=0.008], with benefits lasting through day 7 (p=0.035). Lidocaine administration resulted in a 25% reduction in propofol consumption [230 (208-258) mg compared to 305 (261-354) mg, with a median difference of -71 mg, 95% CI -85 to -57, p<0.001]. Additionally, injection pain scores were significantly lower in the lidocaine group [median score of 0 (0-1) versus 1 (0-3), p<0.001]. The incidence of hypotensive episodes was also reduced with lidocaine administration (12.8% compared to 24.8%, p=0.019). Importantly, no lidocaine toxicity was observed. CONCLUSION: Intravenous lidocaine was associated with enhanced cognitive recovery on postoperative day 3, as well as decreased propofol requirements, injection pain, and hypotensive episodes during ESD. These results indicate that lidocaine may serve as an effective adjuvant in endoscopic sedation protocols. REGISTRATION: ClinicalTrials.gov, NCT05750056.