Abstract:Objective To explore the relationship between serum chloride level and acute kidney injury (AKI) in patients with sepsis and sepsis shock after 72 h of normal saline resuscitation. Methods Using a retrospective cohort study, 200 patients with sepsis, who were admitted to the intensive care unit of the First Hospital of Shanxi Medical University from January 2015 to May 2019, were resuscitated with normal saline at early stage and divided into high chloride group ( ≥ 110mmol/L) and non-high chloride group (< 110mmol/L), according to serum chlorine after 72 h. The initial serum chloridion and creatinine, the highest serum chloridion and creatinine after 72 h, basal creatinine clearance rate (Ccr), initial acute physiology and chronic health evaluation Ⅱ score (APACHE Ⅱ ), mechanical ventilation, renal replacement therapy and other indicators were observed and the changes of serum chloridion were calculated. Results After 72 h of resuscitation, the incidence of AKI in the high-chlorine group was 37.33% (28/75), which was higher than the non-high-chlorine group [16.00% (20/125)] (P < 0.05). There were significant differences in Age, sex, mechanical ventilation, renal replacement therapy, Ccr, APACHE Ⅱ score, the highest serum chloride concentration after 72 hours and the change of serum chloride concentration after 72 hours between two groups (P < 0.05); univariate Logistic regression analysis found that the highest serum chloridion after 72 h was related to AKI (P < 0.05). Serum chloridion change≥1.5 mmol/L and serum chloridion change≥5.5 mmol/L were related to AKI (P < 0.05). After multivariate Logestic regression analysis, it was found that APACHE Ⅱ score [Ol^R = 2.451 (95% CI: 1.961, 2.880), P = 0.000], the highest serum chloridion after 72 h [Ol^R = 2.023 (95% CI: 1.991, 3.211), P = 0.010] and serum chloridion change [Ol^R = 3.211 (95% CI: 2.347, 3.630), P = 0.006] were risk factors for AKI. Conclusions Serum high chloride was independently associated with AKI after 72 h of resuscitation in patients with sepsis, and serum chloridion change and APACHE Ⅱ scores were also related to AKI.