Hepato-renal syndrome

Hepato-renal Syndrome

Hepato-renal syndrome (HRS) is a life-threatening medical condition that involves rapid deterioration of kidney function in individuals with advanced liver disease. It is a type of functional renal failure that occurs in the setting of cirrhosis, severe alcoholic hepatitis, or fulminant hepatic failure.

Pathophysiology

Hepato-renal syndrome is characterized by intense renal vasoconstriction and reduced renal blood flow, leading to kidney failure. The exact mechanism is not fully understood, but it is believed to involve:

• Splanchnic vasodilation: Due to portal hypertension, there is increased production of vasodilators such as nitric oxide in the splanchnic circulation, leading to systemic vasodilation.
• Activation of vasoconstrictor systems: In response to systemic vasodilation, the body activates vasoconstrictor systems like the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system, which preferentially constrict renal blood vessels.
• Imbalance of vasoactive substances: There is an imbalance between vasodilators and vasoconstrictors, contributing to renal hypoperfusion.

Types

Hepato-renal syndrome is classified into two types:

• Type 1 HRS: Characterized by a rapid decline in kidney function, with a doubling of serum creatinine to >2.5 mg/dL or a 50% reduction in creatinine clearance to <20 mL/min in less than two weeks.
• Type 2 HRS: A more gradual decline in kidney function, often associated with refractory ascites.

Diagnosis

The diagnosis of hepato-renal syndrome is clinical and involves the exclusion of other causes of renal failure. The criteria include:

• Presence of chronic or acute liver disease with advanced hepatic failure and portal hypertension.
• Serum creatinine >1.5 mg/dL.
• Absence of shock, ongoing bacterial infection, or current treatment with nephrotoxic drugs.
• No improvement in renal function after diuretic withdrawal and volume expansion with albumin.

Treatment

The management of hepato-renal syndrome includes:

• Vasoconstrictor therapy: Medications such as terlipressin, norepinephrine, or midodrine combined with octreotide are used to improve renal perfusion.
• Albumin infusion: Used to expand plasma volume and improve circulatory function.
• Liver transplantation: The definitive treatment for HRS, as it addresses the underlying liver disease.
• Renal replacement therapy: Dialysis may be used as a bridge to transplantation or in patients not eligible for transplantation.

Prognosis

Hepato-renal syndrome has a poor prognosis, especially type 1 HRS, with a median survival of approximately two weeks without treatment. Early recognition and treatment are crucial to improve outcomes.

See Also

• Cirrhosis
• Portal hypertension
• Renal failure

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NIH genetic and rare disease info

• NIH info on Hepato-renal syndrome

Hepato-renal syndrome is a rare disease.