Introductory Chapter: Principles and Methods of Acute Therapies

Continuous renal replacement therapy (CRRT) is a slow and smooth continuous extracorporeal blood purification. CRRT is usually implemented over 24 h to several days with an aim of gentle removal of fluid overload and excess uremic toxins, where the continuous filtration simulates the continuity of kidney functions. It is usually indicated in critically ill and hemodynamically unstable (adult and pediatric) patients with acute kidney injury (AKI) and/or multiorgan failure, sepsis/shock, acute brain injury, or other causes of increased intracranial pressure or generalized brain edema in intensive care unit (ICU), where such patients cannot tolerate the relatively fast removal of fluids (and solutes) by conventional hemodialysis (HD).