Overview and classification of hepatorenal syndrome
Hepatorenal syndrome (HRS) is a functional kidney failure occurring predominantly in patients with advanced cirrhosis (usually those with severe ascites and hyponatraemia). It can be precipitated by infection (particularly spontaneous bacterial peritonitis), diuretics, nephrotoxic drugs, gastrointestinal bleeding or large-volume paracentesis.
The diagnostic criteria for hepatorenal syndrome are complex and require exclusion of other causes of kidney injury1. Keep in mind that kidney impairment in patients with cirrhosis is not always due to hepatorenal syndrome; see above for other causes.
Strategies that may prevent kidney impairment in patients at risk of hepatorenal syndrome include:
- monitoring diuretic use, and adjusting doses or stopping therapy if hyponatraemia or kidney impairment develops
- giving intravenous albumin to patients undergoing large-volume paracentesis (see refractory ascites) and high-risk patients with spontaneous bacterial peritonitis
- giving prophylactic antibiotics to patients with cirrhosis and upper gastrointestinal bleeding (see Prevention of infection in patients with cirrhosis and upper gastrointestinal bleeding)
- avoiding nephrotoxic drugs (eg aminoglycosides, nonsteroidal anti-inflammatory drugs [NSAIDs], contrast agents).
Two main types of hepatorenal syndrome have been described; these have recently been reclassified based on whether the kidney injury is acute or chronic, and the duration of kidney dysfunction—see Classification of hepatorenal syndrome. Hepatorenal syndrome—acute kidney injury (HRS-AKI) (previously known as type 1 hepatorenal syndrome) is associated with a rapidly rising serum creatinine concentration and a poor prognosis. Hepatorenal syndrome—no acute kidney injury (HRS-NAKI) (previously known as type 2 hepatorenal syndrome) usually causes deterioration in kidney function over weeks to months. It is further subclassified according to the duration of kidney dysfunction (less than or more than 3 months).
|
Classification |
Subtype |
Description |
|---|---|---|
|
HRS-AKI Hepatorenal syndrome—acute kidney injury (previously type 1 hepatorenal syndrome) |
– |
acute kidney injury (eg increase in serum creatinine of 50% or more from baseline within 48 hours), in the absence of other causes |
|
HRS-NAKI Hepatorenal syndrome—no acute kidney injury (previously type 2 hepatorenal syndrome) |
HRS-AKD Hepatorenal syndrome—acute kidney disease |
eGFR less than 60 mL/min/1.73m2 (or increase in serum creatinine of 50% or more from baseline) for less than 3 months, in the absence of other causes |
|
HRS-CKD Hepatorenal syndrome—chronic kidney disease |
eGFR less than 60 mL/min/1.73m2 (or increase in serum creatinine of 50% or more from baseline) for 3 months or longer, in the absence of other causes | |
|
Note: eGFR = estimated glomerular filtration rate | ||