EFFECTS OF DEXMEDETOMIDINE ON POSTOPERATIVE OXIDATIVE STRESS, INFLAMMATORY CYTOKINES AND COGNITIVE FUNCTION IN ELDERLY PATIENTS UNDERGOING NEUROSURGERY UNDER GENERAL ANESTHESIA

Wenwen Luo¹, Wenzi Luo², Manhe Zhang¹, Zhili Liu³, Geng Ning¹, Bin Hu¹, Li Yang^{1, *}

¹Department of Anesthesiology, Tangshan Gongren hospital, Tangshan, Hebei 063007, China - ²Department of Radiotherapy, North China University of Science and Technology Affiliated Hospital, Tangshan, Hebei 063000, China - ³Department of Radiotherapy,

Tangshan Hospital of Traditional Chinese Medicine, Tangshan, Hebei 063000, China

Introduction: To explore the effect of dexmedetomidine infusion on postoperative oxidative stress and cognitive function in elderly patients under general anesthesia after neurosurgery. 

Materials and methods: A total of 128 elderly patients undergoing neurosurgery under general anesthesia from January 2019 to December 2019 were selected. Medication factors (level 2: dexmedetomidine, normal saline) were randomly divided into observation group and control group, with 64 cases in each group. The subjects underwent the same anesthesia, surgery, and intraoperative analgesia. Peripheral blood was collected on the 3rd day after operation, and the contents of superoxide dismutase (SOD) and reactive oxygen species (ROS) as well as the contents of neuron-specific enolase (NSE) and autophagy marker molecule (LC3 II) in excised brain tissues were detected by enzyme-linked immunosorbent assay (ELISA). The plasma cortisol (COR) and interleukin-6 (IL-6) levels of the two groups of patients were measured. The Rey Auditory Verbal Learning Test and the Beck Depression Inventory (BDI) were used for early neuropsychological assessment. 

Results: The use of different analgesics in the neurosurgery of patients had different effects on the oxidative stress and cognitive function after the operation. Those treated with dexmedetomidine showed less oxidative stress and better cognitive function. There was no statistically significant effect of the medication method and the operation time course on the observation indicators. Medication factors exerted an impact on the NSE and LC3 II contents in the brain tissues of the subjects. The NSE content in the brain tissues of the subjects receiving dexmedetomidine was lower than that of the saline patients. The levels of COR and IL-6 in the observation group were significantly lower than those in the control group, and the differences were statistically significant (P<0.05). 

Conclusion: Infusion of dexmedetomidine under general anesthesia reduces the oxidative stress of elderly patients after neurosurgery and improves their cognitive function, and the mechanism of dexmedetomidine to reduce perioperative brain injury may be related to the inhibition of neuronal autophagy.