Abstract: Objective To investigate the effects of different concentrations (total doses) of ropivacaine in transversus abdominis plane block on inflammatory markers and short-term postoperative cognitive changes in elderly patients undergoing laparoscopic cholecystectomy.Methods A total of 242 elderly patients planned for laparoscopic cholecystectomy,admitted to our hospital between July 2021 and July 2024,were chosen and randomly allocated into Group A (0.25% ropivacaine concentration,n=80),Group B (0.375% ropivacaine concentration,n=81),and Group C (0.50% ropivacaine concentration,n=81) via the envelope technique.Observe the inflammatory indicators and cognitive functions of patients with different concentrations of ropivacaine.Results There were no statistically significant differences in awakening quality-related indicators among the three groups (P>0.05).Repeated-measures ANOVA showed a significant between-group effect for CRP (F=3.307,df=2,P=0.040);post-hoc tests indicated lower overall CRP in group B vs C (P=0.012).A significant time effect (F=1 505.179,df=3,P<0.001) reflected an immediate postoperative rise followed by a gradual decline.The interaction effect between groups and time was not statistically significant(F=0.981,df=6,P=0.434).It indicates that the CRP level of patients in group B was generally lower than that in group C,and the trends of CRP levels in groups A,B and C over time were consistent.For IL-6,the between-group effect was nonsignificant (F=2.852,df=2,P=0.062);the time effect was significant (F=699.598,df=3,P<0.001),showing an initial increase then decrease.The interaction became nonsignificant after correction (F=2.380,df=6,P=0.034).For TNF-α,the betweengroup effect was significant (F=21.421,df=2,P<0.001);both A and B had lower levels than C (both P<0.001).The time effect was significant (F=374.519,df=3,P<0.001),with levels declining over time,and the group×time interaction was also significant (F=4.084,df=6,P=0.001).For Mini-Mental State Examination (MMSE) scores,both time effect and inter-group effect were statistically significant (P<0.05).The LSDt test indicated that the MMSE scores in Group A and Group B were higher than those in Group C at all postoperative time points,and the differences were statistically significant (P<0.05).All three groups mainly presented with mild pain at different postoperative time points,and there were no statistically significant differences in pain intensity among the groups at different time points (P>0.05).The total incidence of adverse reactions in Group C was higher than that in Group A and Group B,but this difference was not statistically significant (18.52% vs.7.50% vs.8.64%,χ2=5.796,P=0.055).Conclusion 0.25% and 0.375% ropivacaine for transversus abdominis plane block provide superior suppression of inflammatory response and preservation of postoperative cognitive function compared with the 0.50% total dose,without increasing adverse-event risk.

Key words: laparoscopic cholecystectomy, elderly patients, ropivacaine, transversus abdominis plane block