Effect of Intravenous Lidocaine on Postoperative Cognitive Dysfunction in Patients Undergoing General Anesthesia Surgery: A Systematic Review of a Randomized Controlled Trial.

Purpose: Postoperative cognitive dysfunction (POCD) is a common neurologic complication that occurs after surgery, which prolongs the hospital stay of patients to a certain extent, increases the occurrence of complications, and even leads to the patient's death. Intravenous lidocaine can reduce perioperative inflammatory response in patients undergoing surgery, but its effect on postoperative cognitive function has not been systematically evaluated. Notably, prior findings regarding the impact of intravenous lidocaine on postoperative cognitive function have been variable. Therefore, on this basis, this study explored the effects of intravenous lidocaine on postoperative cognitive function of patients undergoing general anesthesia through a systematic review and meta-analysis.

Methods: Pubmed, Cochrane Library, Embase, Medline, Wanfang Medical Database, China Biomedical Literature Database, and China Academic Journals Full-Text Database were searched from inception to February 2024 for relevant studies that investigated effect of intravenous lidocaine on POCD in patients undergoing general anesthesia surgery. Key data obtained from the referenced literature included the prevalence of POCD, scores from the Mini-Mental State Examination (MMSE), and perioperative serum concentrations of neuron-specific enolase (NSE) and central nervous specific protein (S-100β) protein, serving as biomarkers for central nervous system specificity. Meta-analysis of data was performed using RevMan5.3 software. The software Trial Sequential Analysis (version 0.9) (TSA) was used to analyze high-quality literature focusing on POCD outcome indicators to explore the reliability of the results of meta-analysis.

Findings: Twenty-five studies were included for quality evaluation and data analysis. The studies compared the effect of intravenous lidocaine on the incidence of POCD in patients undergoing surgery at different time points. Subgroup analysis was used to investigate the incidence of POCD at different time points. The results showed that intravenous lidocaine significantly reduced the incidence of POCD at 1, 3, 7, 9 days and 1 year after surgery compared with the control group (on the first day postoperatively: odds ratio (OR) = 0.48, 95% CI: 0.32-0.69, P < 0.001; postoperative day 3: OR = 0.42, 95% CI: 0.25-0.72, P = 0.002; postoperative day 7: OR = 0.34, 95% CI: 0.21-0.55, P < 0.001; postoperative day 9: OR = 0.32, 95% CI: 0.17-0.61, P < 0.001; 1 year postoperatively: OR = 0.39, 95% CI: 0.28-0.54, P < 0.001). The incidence of POCD in patients undergoing general anesthesia at postoperative day 1 with lidocaine was analyzed sequentially. The results showed that with the increase of the included sample size, the Z-curve still did not exceed the TSA boundary and did not reach the required information size. Fourteen studies compared MMSE scores before, 1, 2, 3, and 7 days after surgery between the 2 groups. The results showed that the MMSE score of lidocaine group was significantly higher than that of control group on the first and third postoperative day, with statistical significance (P < 0.05). Compared with the control group, the serum concentrations of neuron-specific enolase and central nervous specific protein in the lidocaine group significantly decreased postoperatively and on the first and third day postoperatively.

Implications: Perioperative intravenous lidocaine may improve postoperative cognitive function and reduce the incidence of POCD. However, limited to the current situation of low quality and small sample size, TSA analysis suggests the need for larger high-quality sample to confirm the accuracy of our findings.

Clinical trial number: This is a systematic review, equivalent to a review, and does not require clinical trial registration. We have registered on PROSPERO.

Registration number: CRD42023493992.