From the Guidelines
Hepatorenal syndrome (HRS) is diagnosed using specific criteria that include acute kidney injury (defined as a serum creatinine increase of ≥0.3 mg/dL within 48 hours or a 50% increase from baseline) in a patient with cirrhosis and ascites, absence of shock, no recent use of nephrotoxic drugs, no response to volume expansion with albumin, and no evidence of structural kidney disease, as outlined in the most recent guidelines 1. The diagnostic criteria for HRS have been updated to reflect the current understanding of the condition. The key criteria include:
- Cirrhosis with ascites
- Acute kidney injury, defined as a serum creatinine increase of ≥0.3 mg/dL within 48 hours or a 50% increase from baseline
- Absence of shock
- No recent use of nephrotoxic drugs
- No response to volume expansion with albumin (typically 1 g/kg/day up to 100 g total over 48 hours)
- No evidence of structural kidney disease, as indicated by:
- Absence of proteinuria >500 mg/day
- Absence of hematuria >50 RBCs per high power field
- Normal kidney ultrasound findings HRS is further classified into two types: HRS-AKI, which develops rapidly with serum creatinine doubling to >2.5 mg/dL within two weeks, and HRS-NAKI, which progresses more slowly 1. The pathophysiology of HRS involves splanchnic vasodilation leading to reduced effective arterial blood volume, activation of vasoconstrictor systems, and intense renal vasoconstriction, which explains why vasoconstrictors like terlipressin or norepinephrine combined with albumin are the mainstay of treatment, while liver transplantation remains the definitive therapy 1.
From the Research
Diagnostic Criteria for Hepatorenal Syndrome
The diagnostic criteria for hepatorenal syndrome (HRS) have undergone recent revisions. According to the International Club of Ascites, HRS diagnosis now relies on serum creatinine changes instead of a fixed high value 2. The current consensus definition of HRS includes proposed diagnostic criteria based on changes in serum creatinine levels tailored for high sensitivity and rapid detection to accelerate diagnosis and treatment initiation 3.
Key Diagnostic Features
- Serum creatinine changes are used to diagnose HRS instead of a fixed high value 2
- Urinary biomarkers, such as urinary neutrophil gelatinase-associated lipocalin, can be useful in identifying patients with acute tubular necrosis and should be employed in the diagnostic algorithm 2
- Differential diagnosis with other causes of acute kidney injury (AKI) is crucial, and kidney biomarkers may be useful in this setting 4
Types of HRS
- HRS can be classified into two forms: acute kidney injury (HRS-AKI) and chronic kidney disease 4
- HRS-AKI is a severe form of AKI in patients with cirrhosis, characterized by an abrupt impairment of kidney function, frequently triggered by an infection 4