Hepatorenal

Hepatorenal refers to kidney dysfunction arising in the setting of advanced liver disease, most notably hepatorenal syndrome (HRS). HRS is a functional renal failure in patients with cirrhosis or other severe liver conditions, typically accompanied by ascites and systemic circulatory changes, rather than intrinsic kidney disease.

There are two main forms of HRS. Type 1 is a rapid and progressive decline in kidney function, characterized by a doubling of serum creatinine to 2.5 mg/dL or more within about two weeks, often triggered by infections such as spontaneous bacterial peritonitis. Type 2 progresses more slowly and is usually associated with refractory ascites and stable kidney function for a longer period.

Pathophysiology involves splanchnic vasodilation and reduced effective arterial blood volume due to severe liver disease. This prompts activation of the renin-angiotensin system, sympathetic nervous system, and antidiuretic hormone, causing intense renal vasoconstriction and decreased renal perfusion despite normal kidney structure. Inflammation and systemic factors also contribute.

Diagnosis requires recognizing functional renal failure in cirrhosis with no other obvious cause (no shock, dehydration, nephrotoxins, or intrinsic kidney disease). Urinalysis is typically bland, urine sodium is low, and imaging shows non-obstructive kidneys. FENa can be unreliable in diuretic users; FeUrea may be used in some cases.

Management centers on treating liver disease and supporting kidney function. Albumin infusions with vasoconstrictors (such as terlipressin or norepinephrine) can improve perfusion and renal function in some patients. Avoid nephrotoxins and hold diuretics. Address precipitating factors and consider liver transplantation or transjugular intrahepatic portosystemic shunt in selected cases. Prognosis remains guarded without definitive Liver transplantation.