and contemplated exposures avoided or tailored to reduce the risk of AKI. Risk assessment in community-acquired AKI is different from hospital-acquired AKI, for two main reasons: i) Available evidence on risk factors is largely derived from hospital data and extrapolation to the community setting is questionable. ii) The opportunity to intervene, prior to exposure, is quite limited. Most patients are seen only after having suffered an exposure (trauma, infection, poisonous plant, or animal). However, there is still room to assess such patients, albeit after exposure, in order to identify those who are more likely to develop AKI, thereby requiring closer monitoring and general supportive measures. It may also be helpful to identify such patients in order to avoid additional injury. A more complete discussion of the approach to identification and management of risk for AKI is provided in Appendices C and D. 2.2.1: We recommend that patients be stratified for risk of AKI according to their susceptibilities and exposures. (1B) 2.2.2: Manage patients according to their susceptibilities and exposures to reduce the risk of AKI (see relevant guideline sections). (Not Graded) 2.2.3: Test patients at increased risk for AKI with measurements of SCr and urine output to detect AKI. (Not Graded) Individualize frequency and duration of monitoring based on patient risk and clinical course. (Not Graded) RATIONALE There are many types of exposures that may cause AKI (Table 6) and these are discussed in detail in Appendix C. However, the chances of developing AKI after exposure to the same insult differ among different individuals. This is attributed to a number of susceptibility factors which vary widely from individual to individual. Our understanding of susceptibility factors (Table 6) is based on many observational studies that address different settings with regards to the type, severity, duration, and multiplicity of insults. While this heterogeneity provides insight into some susceptibility factors that are common across various populations, the generalizability of results from one particular setting to the next is uncertain. The course and outcome of AKI are modified by other factors, but since these are manifested within the context of actual disease, they must be categorized as ‘‘prognostic’’ rather than ‘‘risk’’ factors, hence being discussed separately in Appendix D. Lastly, the fact that some 30% of patients who recover from AKI remain at increased risk of CKD, cardiovascular disease, and death calls for the identification of the risk factors that can identify such patients in the hopes of providing them with timely preventive measures.50–52 Finally, it is important to screen patients who have undergone an exposure (e.g., sepsis, trauma) and to continue monitor high-risk patients until the risk has subsided. Exact intervals for checking SCr and in which individuals to monitor urine output remain matters of clinical judgment; however, as a general rule, high risk in-patients should have SCr measured at least daily and more frequently after an exposure, and critically ill patients should have urine output monitoring. This will necessitate urinary bladder catheterization in many cases, and the risks of infection should also be considered in the monitoring plan. A recent clinical practice assessment in the UK concluded that only 50% of patients with AKI were considered to have received a ‘‘good’’ overall standard of care. This figure fell to http://www.kidney-international.org chapter 2.2 & 2012 KDIGO Table 6 | Causes of AKI: exposures and susceptibilities for non-specific AKI Exposures Susceptibilities Sepsis Dehydration or volume depletion Critical illness Advanced age Circulatory shock Female gender Burns Black race Trauma CKD Cardiac surgery (especially with CPB) Chronic diseases (heart, lung, liver) Major noncardiac surgery Diabetes mellitus Nephrotoxic drugs Cancer Radiocontrast agents Anemia Poisonous plants and animals CKD, chronic kidney disease; CPB, cardiopulmonary bypass. Kidney International Supplements (2012) 2, 19–36 23 just over 30% if AKI developed during a hospital admission rather than being diagnosed before admission.53 The authors also felt that there was an unacceptable delay in recognizing AKI in 43% of those that developed the condition after admission, and that in a fifth of such patients its development was predictable and avoidable. Their recommendations were simple: risk assessment for AKI as part of the initial evaluation of emergency admissions, along with appropriate serum biochemistry on admission and at frequent intervals thereafter.53 RESEARCH RECOMMENDATIONS K Better delineation of risk for hospital- and communityacquired AKI is needed. K Better delineation of the effects of age on the risk for AKI is needed. K Studies are needed to develop and validate scoring systems for AKI risk prediction in various settings, in addition to cardiac surgery and exposure to radiocontrast material. K Genome-wide association studies are needed to determine risk of AKI in different hospital settings and with respect to long-term outcomes. K Studies are needed on risk factors for the development of, recovery from, and long-term outcomes of communityacquired AKI, including sepsis, trauma, tropical infections, snake bites, and ingestion of toxic plants, etc. SUPPLEMENTARY MATERIAL Appendix C: Risk Determination.