Effect of Intravenous Lidocaine on Postoperative Cognitive Dysfunction in Patients Undergoing Laparoscopic Colorectal Surgery: A Two-Center, Randomized, Double-Blind Controlled Trial.

BACKGROUND

In patients undergoing gastrointestinal surgery, enhancing perioperative cognitive function and facilitating expedited postoperative recovery are critical components for achieving swift rehabilitation. Intravenous administration of lidocaine has been shown to mitigate the perioperative inflammatory response in surgical patients; however, its influence on postoperative cognitive performance remains unassessed. Consequently, this study was conducted to investigate the impact of intravenous lidocaine on postoperative cognitive function in participants undergoing laparoscopic surgery for colorectal cancer.

METHODS

We performed a prospective, randomized controlled trial at The First People's Hospital of Changde City and Zhongshan People's Hospital to assess the impact of intravenous lidocaine on postoperative cognitive dysfunction (POCD) in patients undergoing laparoscopic radical resection for colorectal carcinoma. The primary endpoints of our investigation included Mini-Mental State Examination (MMSE) scores measured preoperatively and 7 days postoperatively, as well as the incidence of POCD at the 7-day mark following surgery. Secondary outcomes comprised an evaluation of recovery parameters in the postanesthesia care unit, overall length of hospitalization, and the prevalence of postoperative complications in both study cohorts.

RESULTS

The occurrence of POCD at day 7 postsurgery was significantly lower in the lidocaine group compared to the placebo group ( < 0.05). When stratified by age, both elderly patients (≥65 years) and nonelderly patients in the lidocaine group exhibited a significantly reduced incidence of POCD on the seventh day postoperatively compared to the placebo group ( < 0.05). Preoperative MMSE scores were comparable between the two groups; however, on the seventh day after surgery, the lidocaine group had significantly higher MMSE scores than the placebo group ( < 0.05). In the nonelderly cohort, MMSE scores were also significantly elevated in the lidocaine group compared to the placebo group at day 7 postsurgery ( < 0.05). Mediation analysis indicated that lidocaine's influence on the incidence of POCD on the seventh postoperative day was partially mediated by propofol. Furthermore, there were no significant differences observed in intraoperative medication, postoperative recovery, or perioperative adverse events between the groups ( > 0.05).

CONCLUSIONS

Perioperative administration of intravenous lidocaine has been shown to significantly enhance cognitive function on the seventh postoperative day following laparoscopic colorectal surgery. The mediating influence of propofol on the association between lidocaine and the occurrence of POCD at this time point was determined to be 10%.