Relationship between CRP Albumin Ratio and the Mortality in Critically Ill Patients with AKI: A Retrospective Observational Study

BACKGROUND: AKI is known to be associated with inflammation and nutritional status. The novel inflammatory prognostic score CAR (CRP/albumin ratio), which combines inflammation and nutritional status, was hypothesized to be associated with mortality in critically ill AKI patients in this study. METHODS: The included cases were patients admitted to the ICU of Shandong Provincial Hospital from January 2016 to November 2018 and diagnosed with AKI within 48 hours of ICU admission. From the electronic case database of Shandong Provincial Hospital, we extracted the baseline demographic information, vital signs, routine laboratory parameters, complications, and other data. The above records are measured within 48 hours of admission to ICU. The clinical endpoint was the total cause mortality rate in hospital and 2 years. We constructed two multivariate regression models to determine the statistically significant correlation between CAR and mortality and conducted subgroup analysis to determine the mortality among different subgroups. RESULTS: A total of 580 patients were included in this study. In multivariate regression analysis, higher CAR was associated with an increase in hospital and two-year all-cause mortality in critically ill patients with AKI after adjusting gender, age, respiratory frequency, temperature, and other confounding factors (tertile 3 versus tertile 1: OR, 95% CI: 2.97, 1.70-5.17; 3.03, 1.68-5.47, respectively; P < 0.001). Subgroup analysis showed that the CAR level in each subgroup increases with hospital mortality in critically ill patients with AKI. CONCLUSION: The increase of CAR in critically ill patients with AKI was associated with an increased risk of all-cause death.