The incidence of acute kidney injury (AKI) among all hospitalized patients is approximately 7%. Among these patients, sepsis and septic shock remain the most important cause of acute renal failure (ARF) and account for more than 50% of cases of AKI. The goal of this project is to uncover key factors that lead to renal function recovery. This study is planned to survey novel biomarkers that reflect tissue pathology or regeneration. During the hospitalization, blood and urine sample will be collected for NGAL and inflammatory marker analysis in the patients with bacteremia, while the rest sample will be collected for further novel biomarker survey. This study is to early predict the renal function impairment and identify the possible molecule that involved in renal function recovery.