Diuretika bei kardiorenalen Syndromen

Cardiorenal syndromes are well-defined diseases of the heart and kidneys and five forms can be distinguished which are divided into acute and chronic, as well as primary cardiac and primary renal forms. Triggering and predisposing factors contribute to the development of acute renal failure. Diuretics are necessary and indispensible drugs in cases of fluid overload in acute cardiorenal syndromes. In acute decompensated heart failure diuretics are recommended for the symptomatic treatment of hyperhydration. A benefit of diuretics with respect to hard endpoints (e.g. cardiovascular events and mortality) has not been demonstrated in chronic heart failure and chronic cardiorenal syndromes. Loop diuretics, thiazide diuretics, potassium-sparing diuretics and vasopressin V2 antagonist are available with varying mechanisms and sites of action. The maximum recommended dose of diuretics depends on renal function. Major side effects include electrolyte disturbances (e.g. hypokalemia, hyponatremia and hypomagnesemia), disorders of acid-base balance, increased insulin resistance and ototoxicity. The use of diuretics in cases of renal failure reduces the chance of recovery of renal function. A sequential nephron blockade and/or transient ultrafiltration or renal replacement therapy (e.g. hemodialysis and peritoneal dialysis) might be of benefit in cardiorenal syndromes and resistance to conventional treatment but evidence from controlled studies is still lacking.