Abstract:Objective To investigate the effects of dexmedetomidine on neuroprotection in anesthesia of patients undergoing cardiac valve replacement and on post-operative cognitive function. Methods Eighty-eight patients undergoing cardiac valve replacement from August 2015 to March 2018 were selected and divided into study group and control group (n=44,each).Dexmedetomidine was used before anesthesia induction and maintained until the end of operation in study group,while the same amount of normal saline was given in control group.At anesthesia induction before operation (T₀),after cessation of operation (T₁),the third day (T₂) and the seventh day after operation (T₃),the levels of IL-6 and TNF- α,jugular venous oxygen saturation(SjvO₂),arterio-jugular venous oxygen content difference(Da-jvO₂) and cerebral oxygen extraction rate (CE-RO₂) were compared between two groups.At 1 day before operation,T₂ and T₃,the mental and cognitive levels were evaluated by mini mental state examination (MMSE) and Montreal cognitive assessment scale(MoCA). Results Repeated measurement analysis of variance showed that there were statistical differences in time-,interaction- and inter-group-effect of levels of IL-6,TNF-α,SjvO₂,Da-jvO₂ and MMSE score,MoCA score(all P<0.01);there were statistical differences in time effect and inter-group effect of CE-RO₂ (all P<0.05),but not in its interaction effect in two groups (all P>0.05).At T₀,T₁,T₂ and T₃,the levels of IL-6,TNF-α significantly decreased in study group compared with those in control group (all P<0.01).In both groups,the levels of IL-6 and TNF-α increased at T₁ and decreased significantly at T₀,T₂ and T₃ compared with T₁ (all P<0.05);SjvO₂ level increased significantly at T₁,and then decreased progressively and were significantly lower in control group than that in study group at T₁,T₂ and T₃ (all P<0.05);Da-jvO₂ and CE-RO₂ decreased significantly at T₁,and then increased progressively and were significantly higher in control group than those in study group at T₁,T₂ and T₃ (all P<0.05).At T₂ and T₃,the scores of MMSE and MoCA in control group were significantly lower than those in study group(all P<0.01). Conclusion Dexmedetomidine can protect the nerves,improve the state of cerebral hypoxia reperfusion,play the role of protecting brain tissue in anesthesia of patients undergoing cardiac valve replacement,reduce the incidence of post-operative cognitive disorders and improve the quality of life of patients.