Effects Of Dexmedetomidine On Serum B-FABP And H-FABP Levels In Elderly Patients Undergoing Radical Colorectal Cancer Surgery

Objective:To observe the effects of dexmedetomidine on serum brain fatty acid binding protein（B-FABP）and heart fatty acid binding protein（H-FABP）in elderly colorectal cancer patients receiving radical resection,and to analyze the correlation between perioperative nerocognitive disorders and two fatty acid binding proteins.Methods:Seventy-six patients,aged 65-85 years,who underwent laparoscopic radical colorectal cancer surgery in the First Affiliated Hospital of Hebei North University from January 2021 to December 2021were selected.By random number table method,the patients were randomly divided into two groups:study group（group D）and control group（group C）,including 40 cases in group D and 36 cases in group C.In group D,Dex（0.5μg/kg）was intravenously infused within 10 min before anaesthesia（all were diluted to 4μg/m L with normal saline）.Then,the rate of 0.5μg·kg^-1·h^-1was persistently infused.In group C,saline,instead of Dex,was infused with the same regimen as Dex,and both groups were infused 30 min before the end of operation.General information of two groups were recorded,including gender,age,ASA grade,body mass index,years of education,operation time,blood loss,etc.Invasive arterial blood pressure（SBP,DBP,MAP）,heart rate（HR）,electrocardiogram（ECG）,pulse oxygen saturation（Sp O2）were monitored continuously during the operation.The partial pressure offend-tidal carbon dioxide was monitored and maintained at 35-45mm Hg.The anesthesia depth was monitored with bispectral indexand the bisspectral indexvalues（BIS）maintained at 40-60.The serum levels of brain fatty acid binding protein（B-FABP）and heart fatty acid binding protein（H-FABP）were detected before surgery（T0）,6h after surgery（T1）,24h after surgery（T2）,and 72h after surgery（T3）with enzyme-linked immune sorbent assay（ELISA）.Mini-mental State Examination（MMSE）scores were evaluated at 1 d before surgery,1^std,3^rdd,7^th d after surgery.The incidence of perioperative nerocognitive disorders（PND）in two groups was analyzed.Results:A total of 70 cases were included in this study,35 cases in each group.There was no significant difference in serum levels of B-FABP and H-FABP between group D and group C before surgery.The serum levels of B-FABP and H-FABP increased more signiticantly at 6h and 24h after surgery in two groups,and the difference was statistically significant compared with that before surgery（P<0.05）.Compared with group C,the serum levels of B-FABP and H-FABP in group D were decreased at 6h and24h after surgery,and the difference was statistically significant at the same time point（P<0.05）.Different concentrations of B-FABP and H-FABP wihch were groped by quartile division method were positive correlative with incidence of PND.Spearman correlation analysis of B-FABP and H-FABP were positivetly correlated with the PND（R=0.553,P<0.01,and R=0.765,P<0.05,respectively）.The incidence of PND in group D was lower than that in group C on the 1^st day,3^rd day and 7^th day postsurgery,and the difference between the two groups was statistically significant（P<0.05）.Conclusion:Dexmedetomidine can reduce the levels of B-FABP and H-FABP in colorectal cancer patients receiving radical resection,suggesting that it may have protective effects on Brain function injury and can improve neurocognitive function.The increase of serum level of B-FABP and H-FABP after surgery was positively correlated with the increase of PND.Dexmedetomidine can reduce the incidence of PND in elderly patients.