Acute kidney injury (AKI) is a heterogeneous clinical syndrome that has multiple aetiologies, variable pathogenesis and diverse outcomes. However, these heterogeneities are not reflected in current approaches to the diagnosis and, to some degree, treatment of AKI. For example, congestive heart failure and dehydration can produce identical changes in serum creatinine level and urine output (parameters that are used to define AKI); however, they differ vastly in their physiological contexts and demand completely opposite treatments. AKI is often still considered to be a homogeneous clinical entity, which implies a uniform pathogenesis and a well-defined prognosis. As a consequence, efforts to find effective AKI treatments have been hampered by a lack of clear clinical classifications for various types of AKI. In addition, subclassification of AKI into subclinical phenotypes — for example, on the basis of protein biomarkers and other in vitro diagnostics that take into account disease aetiology and underlying pathogenesis — might be necessary to develop therapeutic approaches that effectively target the widely differing pathomechanisms of AKI. In this Review, we discuss the major subtypes of AKI that are associated with sepsis, major surgery, renal hypoperfusion and nephrotoxin exposure —situations that are typically seen in the intensive care setting. We consider differences and similarities in their phenotype, pathogenesis and outcomes and how this information might be used to guide treatment.

急性肾损伤（AKI）是一种异质性临床综合征，具有多种病因，可变的发病机制和多种预后。但是，这些异质性并未反映在当前的AKI诊断和某种程度上的治疗方法中。例如，充血性心力衰竭和脱水会导致血清肌酐水平和尿量产生相同的变化（用于定义AKI的参数）；但是，它们的生理情况差异很大，因此需要完全相反的治疗方法。AKI通常仍被认为是同质的临床实体，这意味着均匀的发病机制和明确的预后。结果，由于缺乏针对各种类型的AKI的明确临床分类，阻碍了寻找有效AKI治疗的努力。此外，考虑到疾病病因和潜在发病机理的体外诊断，对于开发有效针对AKI广泛不同的发病机理的治疗方法可能是必要的。在本综述中，我们讨论了与脓毒症，大手术，肾灌注不足和肾毒素暴露相关的AKI的主要亚型，这些情况通常在重症监护室中常见。我们考虑了它们的表型，发病机理和结果的差异和相似性，以及如何使用这些信息来指导治疗。