From the Guidelines
Hepatorenal syndrome (HRS) is diagnosed through a process of exclusion after ruling out other causes of acute kidney injury in patients with advanced liver disease, with the presence of cirrhosis with ascites, acute kidney injury (defined as serum creatinine increase ≥0.3 mg/dL within 48 hours or ≥50% from baseline), absence of shock, no recent use of nephrotoxic drugs, no response to volume expansion with albumin, and no evidence of parenchymal kidney disease, as outlined in the most recent guidelines 1. The diagnostic criteria for HRS include:
- Presence of cirrhosis with ascites
- Acute kidney injury, defined as serum creatinine increase ≥0.3 mg/dL within 48 hours or ≥50% from baseline
- Absence of shock
- No recent use of nephrotoxic drugs
- No response to volume expansion with albumin (1 g/kg/day up to 100 g/day for 2 days)
- No evidence of parenchymal kidney disease (as indicated by significant proteinuria, microhematuria, or abnormal kidney ultrasound) HRS is classified into two types:
- HRS-AKI (formerly type 1), characterized by rapid deterioration in kidney function
- HRS-NAKI (formerly type 2), which involves more gradual decline, as described in the revised classification by the International Club of Ascites 1. The diagnosis of HRS is crucial, as it carries high mortality, especially if untreated, and proper diagnosis guides appropriate management with vasoconstrictors like terlipressin or norepinephrine combined with albumin, with the combination of terlipressin and albumin shown to significantly improve renal function in HRS-AKI and improve short-term mortality 1.
From the Research
Diagnostic Criteria for Hepatorenal Syndrome (HRS)
The diagnostic criteria for HRS are based on the presence of severe acute or chronic liver disease, renal failure, and the absence of underlying renal pathology 2. The diagnosis is determined by positive criteria associated with excluding other causes of renal failure in patients with liver cirrhosis and ascites 2.
Key Diagnostic Factors
- Severe acute or chronic liver disease
- Renal failure
- Absence of underlying renal pathology
- Exclusion of other causes of renal failure in patients with liver cirrhosis and ascites
Classification of HRS
HRS is classified into two types:
- Type I: acute HRS, characterized by a rapid progression of renal failure 3, 4
- Type II: chronic HRS, characterized by a more gradual progression of renal failure 3, 4
Diagnostic Challenges
The diagnosis of HRS can be challenging due to the absence of specific diagnostic markers and the difficulty in differentiating it from other types of acute or chronic renal disease 2. The diagnostic criteria may not be completely fulfilled in all cases, and the presence of precipitating factors such as nephrotoxins, parenchymal kidney damage, hypovolaemia, and infections can complicate the diagnosis 5.
Established Diagnostic Criteria
The International Ascites Club has recommended strict diagnostic criteria for HRS, which include:
- Renal failure, as indicated by an increase in serum creatinine levels
- Absence of underlying renal pathology
- No response to volume expansion with albumin
- No evidence of other causes of renal failure, such as nephrotoxins or sepsis 4