Section 3: Prevention and Treatment of AKI

As discussed in Chapters 2.3 and Appendix D, patients with AKI and at increased risk for AKI require careful attention to be paid to their hemodynamic status. This is first because hypotension results in decreased renal perfusion and, if severe or sustained, may result in kidney injury. Second, the injured kidney loses autoregulation of blood flow, a mechanism that maintains relatively constant flow despite changes in pressure above a certain point (roughly, a mean of 65 mm Hg). Management of blood pressure and cardiac output require careful titration of fluids and vasoactive medication. Vasopressors can further reduce blood flow to the tissues if there is insufficient circulating blood volume. Conversely, patients with AKI are also at increased risk for fluid overload (see Chapter 3.2) and continued fluid resuscitation despite increased intravascular volume can cause harm. Fluids and vasoactive medications should be managed carefully and in concert with hemodynamic monitoring. Hemodynamic evaluation and monitoring are discussed in Appendix D. In this chapter therapies aimed at correcting hemodynamic instability will be discussed. Available therapies to manage hypotension include fluids, vasopressors and protocols which integrate these therapies with hemodynamic goals. There is an extensive body of literature in this field and for a broader as well as more in depth review the reader is directed to the various reviews and textbooks devoted to critical care and nephrology.