What is Hepatorenal (hepatic and renal) syndrome?

From the Guidelines

Hepatorenal syndrome (HRS) is a specific form of renal dysfunction that occurs in patients with cirrhosis and ascites, characterized by rapid reduction in renal function due to altered hemodynamic alterations and systemic inflammation.

Key Characteristics of HRS

• HRS is traditionally thought to be due to hyperdynamic circulation and overactive endogenous vasoactive system, resulting in renal hypoperfusion 1
• Systemic inflammation also plays an important role in the pathophysiology of HRS 1
• The diagnosis of HRS is essentially one of exclusion of other causes of renal failure 1

Classification of HRS

• The traditional classification of HRS-1 and HRS-2 has been revised by the International Club of Ascites 1
• HRS-1 has been proposed to be changed to HRS-acute kidney injury (HRS-AKI), defined as an increase in serum creatinine of ≥0.3 mg/dL within 48 hours or ≥50% from baseline 1
• HRS-2 has been proposed to be changed to HRS-NAKI (non-AKI) 1

Treatment of HRS

• The mainstay of treatment of HRS-AKI involves vasoconstrictors, particularly terlipressin, and albumin infusion 1
• Combination of terlipressin and albumin has been shown to significantly improve renal function in HRS-AKI and improve short-term mortality 1

From the Research

Definition of Hepatorenal Syndrome

• Hepatorenal syndrome (HRS) is defined as a functional renal failure without major histologic changes in individuals with severe liver disease, associated with a high mortality rate 2.
• HRS is a form of kidney dysfunction that characteristically occurs in liver cirrhosis, characterized by a marked impairment of kidney function in response to circulatory and hemodynamic alterations 3.
• HRS is acute kidney injury (AKI) that occurs without evidence of structural abnormalities in the kidneys in patients with liver disease 4.

Pathophysiology of Hepatorenal Syndrome

• Renal hypoperfusion due to marked vasoconstriction as a result of complex circulatory dysfunction is suggested to be the cornerstone of HRS 2.
• Splanchnic and peripheral arterial vasodilation and cirrhotic cardiomyopathy result in effective arterial hypovolemia and compensatory activation of vasoconstrictor mechanisms 2.
• Systemic inflammation plays a substantial role in HRS via either vascular or direct renal effects 2.
• Splanchnic vasculature dilatation is associated with intense increase of renal arteries' tone, leading to renal cortex ischemia and AKI 4.

Types of Hepatorenal Syndrome

• Two forms of HRS have been redefined: the acute form, referred to as acute kidney injury (HRS-AKI), and the chronic form, referred to as chronic kidney disease (HRS-CKD) 3, 5.
• HRS-AKI is one of the most severe forms of AKI in patients with cirrhosis, consisting of an abrupt impairment of kidney function, frequently triggered by an infection 3.

Management and Treatment of Hepatorenal Syndrome

• Treatment of HRS-AKI is based on the administration of vasoconstrictor drugs in combination with volume expansion with albumin 3.
• Plasma volume restoration and vasoconstrictors are the cornerstone of HRS treatment 4.
• Liver or combined liver and kidney transplantation is currently the ultimate cure for HRS 4, 6.