Hepatorenal syndrome classification
Hepatorenal syndrome (HRS) is classified into HRS-AKI and HRS-NAKI (non-AKI HRS) based on whether kidney dysfunction meets acute kidney injury (AKI) criteria. [1]
HRS-AKI (acute kidney injury)
HRS-AKI corresponds to the prior concept of type 1 HRS (rapidly progressive renal dysfunction). [1]
HRS-NAKI (non–AKI hepatorenal syndrome)
HRS-NAKI corresponds to the prior concept of type 2 HRS and is further subdivided by chronicity using kidney function duration and reduced eGFR. [2]
HRS-AKD and HRS-CKD subdivisions within HRS-NAKI
Within HRS-NAKI, HRS-acute kidney disease (HRS-AKD) is defined as reduced eGFR (<60 mL/min/1.73 m²) for <3 months, while HRS-chronic kidney disease (HRS-CKD) is defined as reduced eGFR (<60 mL/min/1.73 m²) for ≥3 months. [2]
Historical classification
The historical classification divided HRS into type 1 HRS and type 2 HRS, reflecting rapid progressive versus slowly progressive functional renal failure, respectively. [3]