Septic acute kidney injury in critically ill patients - a single-center study on its incidence, clinical characteristics, and outcome predictors.

Purpose The objective of this study is to examine the incidence, clinical characteristics, and outcome (90-day mortality) of critically ill Chinese patients with septic AKI. Methods Patients admitted to the ICU of a regional hospital from 1 January 2011 to 31 December 2013 were included, excluding those on chronic renal replacement therapy. AKI was defined using KDIGO criteria. Patients were followed till 90 days from ICU admission or death, whichever occurred earlier. Demographics, diagnosis, clinical characteristics, and outcome were analyzed. Results In total, 3687 patients were included and 54.7% patients developed AKI. Sepsis was the most common cause of AKI (49.2%). Compared to those without AKI, AKI patients had higher disease severity, more physiological and biochemical disturbance, and carried significant co-morbidities. Ninety-day mortality increased with severity of AKI (16.7, 27.5, and 48.3% for KDIGO stage 1, 2, and 3 AKI, p < 0.001). Full renal recovery was achieved in 71.6% of AKI patients. Compared with non-septic AKI, septic AKI was associated with higher disease severity and required more aggressive support. Non-recovery of renal function occurred in 2.5% of patients with septic AKI, compared with 6.4% in non-septic AKI (p < 0.001). Cox regression analysis showed that age, emergency ICU admission, post-operative cases, admission diagnosis, etiology of AKI, disease severity score, mechanical ventilation, vasopressor support, and blood parameters (like albumin, potassium and pH) independently predicted 90-day mortality. Conclusions AKI, especially septic AKI is common in critically ill Chinese patients and is associated with poor patient outcome. Etiology of AKI has a significant impact on 90-day mortality and may affect renal outcome.