Objective To investigate the effect of dexmedetomidine on renal function in patients with septic-associated acute kidney injury(SAKI).Methods A prospective cohort study was conducted in 180 patients with sepsis admitted to ICU in the Second Affiliated Hospital of Guangdong Medical University from October 2021 to April 2023.According to the principle of randomized controlled trials,60 non-acute kidney injury(AKI)patients were divided into S-D group(n = 30,dexmedetomidine + conventional treatment)and S group(n = 30,conventional treatment),and the occurrence and disease score of AKI after treatment were compared between the two groups.A total of 120 AKI patients were divided into SA-D-RT group(n = 30,dexmedetomidine + blood purification + conven-tional treatment),SA-D group(n = 30,dexmedetomidine + conventional treatment),SA-RT group(n = 30,blood purification + conventional treatment)and SA group(n = 30,conventional treatment).Renal function,inflammatory factor level and disease change of the four groups were compared after treatment.Results After treatment,the inci-dence of AKI in S-D group was lower than that in S group,and the APACHEII score and SOFA score in S-D group were lower than those in S group on the 7th day after treatment(P<0.05).After 7 days of treatment,the level of Scr,BUN and CysC in the 4 groups was significantly lower than that on the 1st and 3rd day,and those in the SA-D-RT group were lower than those in the SA-D group,SA-RT group and SA group(P<0.05).After 7 days of treatment,the level of CRP,PCT,TNF-α,IL-6 and IL-1β in four groups was significantly decreased compared with on the 1st and 3rd day,and the level of CRP,PCT,TNF-α,IL-6 and IL-1β in SA-D-RT group was lower than that in SA-D group,SA-RT group and SA group(P<0.05).After 7 days of treatment,the APACHEII score and SOFA score of the four groups were significantly lower than on the 1st and 3rd day,and the scores of the SA-D group were lower than those of the SA-D group,the SA-RT group and the SA group(P<0.05).Conclusion Dexmedetomidine can effectively reduce the incidence of AKI,affect the expression level of renal function markers and inflammatory factors in serum of SAKI patients,and improve the condition of patients.