ObjectiveTo explore the effect of continuous renal replacement therapy (CRRT) to treat sepsis associated acute kidney injury (AKI) in patients aged over 80.MethodsForty-one patients diagnosed with sepsis and AKI were enrolled in geriatric RICU department of Huadong Hospital from January 2013 to July 2018, 38 patients were male and 3 were female. All patients were treated with anti-infection and fluid resuscitation therapy. After comprehensive judgment of the indication of renal replacement, they were divided into two groups by the choices of using CRRT. There were 20 patients in CRRT group and 21 in control group. Clinical data such as age, body mass index, previous diseases, 28-day mortality rate, blood cells, APACHEⅡ as well as SOFA scores were compared between two groups. Blood renal function and inflammatory markers at the first day were also compared to those after 3-day treatment of initial time.ResultsNo statistical difference was observed in sex ratio, age, body mass index and previous diseases between two groups (all P>0.05). There was also no difference in APACHEⅡ score, SOFA score, blood cells, hemoglobin and survival time. The 28-day mortality rate in CRRT group was lower than that in control group (P<0.05). The levels of serum UA and C reactive protein (CRP) in CRRT group decreased after 3-day treatment compared with those at the onset, and the differences were statistically significant (all P<0.05). The level of serum blood urea nitrogen (BUN), creatinine (Cr), uric acid (UA) and cystain C in control group increased after 3 days compared with those at the onset, and the difference were statistically significant (all P<0.05). There was no significant difference in serum BUN, Cr, UA, cystain C, CRP and procalcitonin (PCT) between two groups at the onset (all P>0.05). After 3 days of CRRT, the levels of serum PCT, BUN, Cr and UA in CRRT group were lower than those in the control group (all P<0.05).ConclusionCRRT can improve hyperuricemia, control deterioration of renal function, reduce early systemic inflammatory response and 28-day mortality rate in aged patients with sepsis and AKI.