Uremia: pathophysiologic sequelae and indications for kidney replacement therapy

Mortality in intensive care unit patients with acute renal failure is still high. The reasons for this are not fully understood. Renal failure without other failing organs does not lead to death if treatment is adequate. Uremia is therefore thought to prevent spontaneous recovery from and impedes the treatment of other organ failures. The reasons for this have been elucidated only partially. Of main importance are different kinetics and dynamics of endo- and xenobiotics in uremia. The mechanisms that lead to altered kinetics in such patients are quite clearly understood, while in the field of altered dynamics many questions are open. It is also unclear which accumulating metabolites are responsible for the different dynamics. This is the reason why parameters that would indicate when to start a dialysis procedure in acute renal failure are still lacking. Exceptions are substances known to lead to death if they are present in high concentrations. These substances are mainly potassium, salt and water.