From the Guidelines
Hepatorenal syndrome (HRS) is a serious complication of advanced liver disease characterized by acute kidney injury in patients with cirrhosis and ascites, occurring in the absence of other identifiable causes of kidney damage, and is typically associated with a pattern of liver function tests (LFTs) that reflect underlying advanced liver disease, including elevated aminotransferases, bilirubin, alkaline phosphatase, and gamma-glutamyl transferase, as well as decreased albumin and prolonged prothrombin time/INR, as noted in studies such as 1. The liver function tests (LFTs) in patients with HRS typically reflect the underlying advanced liver disease, with the following characteristics:
- Elevated aminotransferases (AST and ALT), though these may not be dramatically high in end-stage cirrhosis
- Elevated bilirubin levels
- Prolonged prothrombin time/INR
- Decreased albumin
- Elevated alkaline phosphatase and gamma-glutamyl transferase The severity of these abnormalities generally correlates with the degree of liver dysfunction, as discussed in 1 and 1. It is essential to note that HRS develops due to extreme vasoconstriction of the renal arteries while splanchnic vasodilation causes systemic hypotension, leading to reduced renal perfusion and kidney failure, as described in 1 and 1. Treatment focuses on improving liver function and hemodynamics through vasoconstrictors like terlipressin or norepinephrine combined with albumin, while liver transplantation remains the definitive treatment, as mentioned in 1 and 1. Early recognition is crucial as HRS carries a poor prognosis if not promptly addressed, with type 1 HRS being particularly aggressive with rapid deterioration of kidney function, as noted in 1 and 1.
From the Research
Definition of Hepatorenal Syndrome
Hepatorenal syndrome (HRS) is a functional renal failure that develops in patients with advanced hepatic cirrhosis with ascites and in those with fulminant hepatic failure 2. It is characterized by a marked impairment of kidney function in response to circulatory and hemodynamic alterations that occur in advanced stages of liver cirrhosis, aggravated by systemic inflammation and bacterial translocation 3.
Types of Hepatorenal Syndrome
There are two forms of HRS:
- Type 1, which is characterized by an acute progressive decrease in kidney function and very short survival without treatment 4
- Type 2, which features stable, less severe kidney failure and longer survival compared with type 1 4
Pathophysiology of Hepatorenal Syndrome
HRS is caused by functional impairment of the kidneys due to vasoconstriction of the renal arteries in the setting of preserved tubular function and absence of significant histologic abnormalities 4. Renal vasoconstriction in HRS is due to severe vasodilation of the splanchnic arteries associated with portal hypertension, leading to a decrease in effective arterial blood volume and arterial pressure 4.
Liver Function Tests (LFTs) in Hepatorenal Syndrome
The pattern of LFTs in patients with HRS is not specifically defined, but it is known that HRS occurs in patients with advanced liver disease, including cirrhosis 2, 3, 4, 5. Patients with HRS typically have abnormal LFTs, including elevated liver enzymes and bilirubin levels, due to the underlying liver disease.
Treatment and Management of Hepatorenal Syndrome
Treatment of HRS-AKI is based on the administration of vasoconstrictor drugs in combination with volume expansion with albumin 3. A liver transplant is the preferred treatment for HRS 4. Pharmacologic treatment with vasoconstrictors, such as terlipressin, to reverse splanchnic vasodilation, together with albumin, is effective in 40%-50% of patients with type 1 HRS and improves survival 4. The combination of octreotide, midodrine, and albumin has also been shown to improve survival and renal function in patients with HRS type 1 and type 2 6.
Key Points
- HRS is a functional renal failure that develops in patients with advanced hepatic cirrhosis with ascites and in those with fulminant hepatic failure
- There are two forms of HRS: type 1 and type 2
- HRS is caused by functional impairment of the kidneys due to vasoconstriction of the renal arteries
- The pattern of LFTs in patients with HRS is not specifically defined, but patients typically have abnormal LFTs due to the underlying liver disease
- Treatment of HRS-AKI is based on the administration of vasoconstrictor drugs in combination with volume expansion with albumin, and a liver transplant is the preferred treatment for HRS.