[Continuous renal replacement therapy: management of acute renal insufficiency in critical care units]

Acute renal insufficiency is characterized by a sudden decrease in renal function. Various causes are implicated and the physiopathological mechanisms are quite complex. When kidney failure is associated with other organ or system failure, the patient is usually treated in an intensive care unit. Such "critical status" patients are characterized by severe cardiovascular, respiratory and metabolic unstability that may make conventional methods of dialysis (intermittent hemodialysis and peritoneal dialysis) impossible or inadvisable. Continuous methods of renal replacement include 24-hour extracorporeal blood filtration for an indefinite period of time. Such aspects of renal function as electrolyte regulation of nitrogenated products, inflammatory mediators and so forth are replaced or supplemented by various continuous modes available. In this review we discuss the functions and indications for the continuous renal replacement techniques available. The components of each technique are studied exhaustively with a view to obtaining benefit.