hepatorrenal

Hepatorenal syndrome, sometimes referred to as hepatorenal syndrome, is a form of functional renal failure that occurs in people with advanced liver disease, most commonly cirrhosis with portal hypertension. It involves severe reduction in kidney function despite relatively preserved kidney structure, due to changes in blood flow and fluid regulation driven by liver failure.

The condition arises from splanchnic vasodilation and reduced effective arterial blood volume, which trigger renal vasoconstriction and decreased renal perfusion. Activation of the renin-angiotensin system and sympathetic nervous system further compounds renal hypoperfusion. It typically occurs in the setting of ascites or other decompensated liver disease and may be precipitated by infections, gastrointestinal bleeding, or diuretic use.

Hepatorenal syndrome is classified into two main types. Type 1 is a rapid and dramatic decline in kidney function, usually defined as doubling of serum creatinine to above about 2.5 mg/dL or a similar fall in glomerular filtration rate within two weeks. Type 2 progresses more slowly and is often associated with refractory ascites. It is important to distinguish HRS from intrinsic kidney diseases and other plausible causes of renal impairment.

Diagnosis relies on clinical context in a patient with cirrhosis and ascites, elevated creatinine, and exclusion of other causes. Diagnostic criteria typically include no shock, absence of nephrotoxic drug effects, no sustained improvement after volume expansion with albumin, and evidence against intrinsic renal disease (e.g., relatively low urine sodium and no significant proteinuria). Imaging is used to exclude obstruction.

Management centers on treating liver disease and preventing further injury. Interventions include albumin infusion and vasoconstrictor therapy (such as norepinephrine or terlipressin, often with octreotide), management of infections, avoidance of nephrotoxins, and consideration of transjugular intrahepatic portosystemic shunt in select cases. Liver transplantation is the definitive treatment. Renal replacement therapy may be used as a bridge to transplant in selected patients. The prognosis remains poor without transplantation, particularly for Type 1 HRS.