Continuous Renal Replacement Therapy (CRRT)

Abstract

Continuous renal replacement therapy (CRRT) is a mode of renal replacement therapy that is used for hemodynamic instable, fluid overload, and septic patients complicated by AKI in the critical care/intensive care unit setting. CRRT provides a slow, gentle treatment of AKI and fluid removal much like the native kidney (ultrafiltration up to 120 mL/h) and is generally well tolerated by critically ill, hemodynamically unstable patients. The CRRT is intended to substitute for impaired renal function over an extended period of time and applied for 24 h a day. It provides slower solute clearance per unit time as compared with intermittent hemodialysis therapies, but over 24 h may even exceed clearances with intermittent hemodialysis. CRRT differs considerably from intermittent hemodialysis, relying heavily upon continuous ultrafiltration of plasma water. It has the potential for removal of large quantities of larger-molecular-weight drugs, such as glycopeptide antibiotics, from plasma. Moreover, control of anemia, acid–base balance, and fluid volume can be achieved easily and continuously maintained with CRRT. In addition, CRRT removes inflammatory mediators of sepsis such as TNF-alpha, interleukin, and complement. CRRT can be performed with ultrafiltration (SCUF), hemofiltration (CVVH), or hemodialysis (CVVHD) or a combination of both techniques (CVVHDF). Of these, the CVVH and CVVHD are often used in children requiring CRRT. Potential benefits of CRRT in patients with multiple organ dysfunctions include management of fluid balance, decreasing fluid overload, removal of inflammatory mediators, enhanced nutritional support, and control of electrolyte and acid–base abnormalities.