S-413 : Clinical and microbiologic characteristics of septic acute kidney injury

Background: Acute kidney injury (AKI) in critically ill patinets frequently complicates sepsis and patients with septic AKI present high mortality. However, there is limited information of pathogens and clinical outcomes in septic AKI. We evaluated the microbiologic etiology and clinical characteristics in septic AKI. Methods: We retrospectively reviewed demographic data, blood culture results, clinical manifestations, and outcomes of the AKI patients at intensive care unit (ICU) of Myongji hospital during a 10-year period from 2003 to 2012. Results: During the study period, there were 766 critically ill patients with AKI. Among them, blood culture was performed in 668 (87.2%) and pathogens were isolated in 32.2% of culture-drawn patients. Fifty-eight percent of septic AKI was caused by gram (+) organisms, and 43.9% of septic AKI occurred by multi-drug resistant organisms. The most common pathogen isolated was coagulase-nagative Staphylococcus in gram (+), and Escherichia coli in gram (-) organisms. Coagulase-nagative Staphylococcus, Staphylococcus aureus, Acinetobacter and Proteus species revealed multi-drug resistance frequently. While 41.7% of the patients with gram (+) bacteremia failed to explore the origin of the infection, urinary tract was the most common infection focus in gram (-) sepsis. Platelet count and C-reactive protein were lower and ICU and hospital stay were longer in gram (+) bacteremia than gram (-) bacteremia. There were more ventilated patients in those with multi-drug resistant organisms and they showed longer ICU and hospital stay than the patients with antibiotics sensitive organisms. Overall, the mortality was not different between gram (+) and (-) organisms and drug sensitive and resistant organisms. Cox proportional hazard model showed that acute myocardial infarction, liver cirrhosis, post-resuscitation state, high APACHE 2 score, low mean arterial pressure, number of inotropics use were independent predictors of death. Conclusion: There was diversity of microorganisms that cause septic AKI. Severity of illness and comorbidities predicted mortality regardless of specific pathogens in septic AKI patients.