Li S, et al. - In this retrospective cohort study, researchers analyzed the epidemiology and investigated the variations in risk factors and outcomes between early and late acute kidney injury post-major surgery. Overall 3,499 patients were included in this study. They used full Kidney Disease: Improving Global Outcomes criteria to define acute kidney injury. Based on the time from surgery, acute kidney injury was categorized as early (48 hr or less) or late (> 48 hr to 7 d). Within 48 hours of surgery, the maximum occurrence of surgery-related acute kidney injury was reported. Findings revealed the association of acute kidney injury occurring within the first 48 hours, with underlying health, whereas, a link of acute kidney injury occurring after 48 hours with postoperative complications or drugs was evident.