Renal replacement therapy in the critical care unit.

Acute renal failure is common in critically ill patients. Many intensive care unit patients require renal replacement therapy (RRT). Hemodialysis can be performed as intermittent treatments or as continuous RRT, which can be customized to clinical goals by the use of carefully designed replacement fluids and hemodialysates. The available forms of RRT are reviewed, with emphasis on the clinical indications that contribute to the choice and design of therapy. Practical issues and troubleshooting are discussed, as are available options for anticoagulation during RRT. Consideration is given to modality choice, hemodynamic issues, costs, and physiologic outcomes.