Fluid balance management during continuous renal replacement therapy

In critically ill patients, particularly in the setting of shock and sepsis volume management frequently results in a fluid overloaded state, requiring diuresis or intervention with renal replacement therapy. Achieving appropriate volume management requires knowledge of the underlying cardiovascular pathophysiology and careful evaluation of intravascular and extravascular volume status. In the presence of a failing kidney, fluid removal is often a challenge. Continuous renal replacement therapy (CRRT) techniques offer a significant advantage over intermittent dialysis for fluid control, however, any form of RRT in the critically ill patient requires careful attention to prescription and monitoring to avoid complications. In order to utilize these therapies for their maximum potential it is necessary to understand which factors influence fluid balance and have an understanding of the principles and kinetics of fluid removal with extra-corporeal techniques.