Effects Of Remote Ischemic Preconditioning On Postoperative Cognitive Function In Elderly Patients With Laparoscopic Cholecystectomy

Objective To investigate the effects of remote ischemic preconditioning（RIPC）on postoperative cognitive dysfunction（POCD）in elderly patients following laparoscopic cholecystectomy（LC）.Methods The study selected 88 elderly patients（age 65～74 years）who underwent laparoscopic cholecystectomy in our hospital from November2022 to January 2023.According to the random number table,patients were allocated to the control group（44 patients）or the RIPC group（44 patients）.After the induction of anesthesia,the RIPC was applied on the right upper limb using a blood pressure cuff inflating 200 mm Hg,consisting of 3 cycles of 5 min ischemia and 5 min reperfusion.In the Control group,the tourniquet was only placed in the same position without inflating and deflating.HR,MAP and rSO₂values were recorded in both groups at the time of admission（T1）,in the anti-Trendelenburg position（T2）,in the horizontal position（T3）and at the end of the operation（T4）.Arterial blood gas analysis was performed at the above 4 time points,PaO₂,PaCO₂,Lac,Hb and Glu were recorded.Serum concentrations of Neuron-specific Enolase（NSE）and Brain-Derived Neurotrophic Factor（BDNF）were collected at one day preoperative（T0）,at the end of the operation（T4）and one day postoperative（T5）.Z score was tested at T0 and 3 days after the operation（T6）.Enrolled patients completed the mini-mental state examination（MMSE）,picture recall test（PRT）,Stroop the color test（Stroop test）,digit-symbol test（DST）,number connecting test（NCT）and numerical symbol conversion test（DSST）tests 1 day before the operation（T0）and 3 days after the operation（T6）,each score was recorded.POCD was determined if there were two Z scores≥1.96at the same time or the combined Z score≥1.96.Results1.There were no differences in demographic data between the two groups（P>0.05）.2.There were no differences in MAP,HR,PaO₂,PaCO₂,Lac,Hb,Glu between the two groups at T1,T2,T3 and T4（P>0.05）.3.The values of rSO₂ in the control group at T2 were significantly lower than those in the RIPC group（P<0.05）.4.There was no statistically significant difference in the levels of serum NSE and BDNF between the two groups at T0（P>0.05）.Compared to T0,serum NSE and BDNF concentration was significantly increased in both groups at T4 and T5（P<0.05）.Compared to the control group,serum NSE concentration was decreased in the RIPC group at T4 and T5（P<0.05）.serum BDNF concentration was increased in the RIPC group at T4 and T5（P<0.05）.5.There was no significant difference in the Z score of each test between the two groups at T0（P>0.05）.The duration of Stroop test C was significantly shorter in the RIPC group than that in the Control group at T6（P<0.05）.The incidence of POCD in the control group and RIPC group was18.2%and 2.3%,respectively（P<0.05）.6.Correlation analysis between rSO₂and various neuropsychological tests:There was no correlation between rSO₂ and various neuropsychological tests（P<0.05）.7.Correlation analysis between MMSE and serum biochemical indices:There was no correlation between MMSE and NSE/BDNF（P<0.05）.Conclusion RIPC could reduce the incidence of POCD in elderly patients after LC.