Extracorporeal renal replacement therapies in the treatment of sepsis: where are we?

Acute kidney injury (AKI) is common among the critically ill, affecting approximately 40% of patients. Sepsis is the cause of AKI in almost 50% of cases of intensive care patients, however, any evidence-based treatment for sepsis-associated AKI is lacking. Furthermore, the underlying pathophysiology of septic AKI is inadequately understood given the disparity between severe functional changes and limited tubular injury. What is clear is that within this complex interplay leading to septic AKI, the inflammatory response plays a pivotal role and hence modulation of this response may translate to improved outcomes. We outline the use of extracorporeal therapies in the treatment of sepsis and septic AKI. We consider the classic aspects of extracorporeal renal replacement therapy including indications, timing, and delivered dose. The various techniques that currently are used to try and achieve immune homeostasis also are outlined. As well as discussing the evidence accumulated to date, we also suggest possibilities for the future treatment of our patients.