[Diagnosis and therapy of hepatorenal syndrome]

Hepatorenal syndrome (HRS) is defined as severe vasoconstriction of renal cortical vessels with critical impairment of glomerular filtration rate, initiated by deteriorating liver function. In addition, systemic vasodilation, predominantly of splanchnic vessels is present. Although the urinary status is basically normal, during the course of HRS kidneys are loosing their ability to concentrate and at an urinary production rate of less than 100 ml/day the urinary osmolarity and Na(+)-concentration drops significantly. Because HRS can not be improved by conventional medical treatment regimens, its prophylaxis is of major importance. Besides improvement of liver function and avoidance of drastic volume depletion (bleeding, paracentesis, high dose diuretic therapy) and sepsis, the therapeutic goal is to reverse systemic vasodilation and to achieve a concomitant relaxation of renal arteries. Expansion of plasma volume and application of renal vessel dilating prostaglandins is one strategy. Alternatively, therapy with ornipressin was shown to be successful, which improves renal perfusion and normalizes the hyperdynamic state of systemic circulation.