Acute kidney injury is a common finding in patients in the emergency department. The vast majoreity of these can be reversed by a foley catheter and a bag or two of crystalloids, however understanding what to do for the remainder is an important and often confusing topic. Dr. Topf boils down the science to present acute kidney injury with a practical bent. He covers the common causes as well as the less common diagnosis with an emphasis of what to look for in order to dig deeper, rather than presenting a comprehensive diagnostic algorithm. He also discusses the recent data of the treatment of metabolic acidosis, the initiation of dialysis and how to use and interpret the furosemide stress test.