- Renal failure in patients with advanced liver failure (acute or chronic) in the absence of any identifiable causes of renal pathology.
- All other causes of renal failure, functional or organic, have been excluded.
Renal dysfunction is a common and serious problem in patients with advanced liver disease, estimated to occur in 10% of hospitalized patients with cirrhosis. It is a syndrome characterized by (1) oliguria, severe renal sodium retention, and rapidly progressive azotemia, (2) circulatory instability with marked systemic arterial vasodilation and activation of vasoactive systems, and (3) a very poor prognosis. Without treatment, the median survival for type 1 hepatorenal syndrome patients is on the order of 1–2 weeks, while that for type 2 hepatorenal syndrome is about 20% at 1 year. However, hepatorenal syndrome has always been considered to be a form of functional renal failure, as kidneys from patients with hepatorenal syndrome, when transplanted into someone with renal failure, regain their normal function. Similarly, renal function also improves in patients with end-stage cirrhosis following liver transplantation, although the renal function can remain abnormal for quite sometime in the postoperative period.
Hepatorenal syndrome is defined as the development of renal failure in patients with advanced liver failure (acute or chronic) in the absence of any identifiable causes of renal pathology. It is a diagnosis of exclusion, when all other causes of renal failure, functional or organic, have been excluded. The International Ascites Club further defines the criteria for the diagnosis of hepatorenal syndrome, as detailed in Table 10–1. It must be emphasized that urinary parameters are supportive, but not essential for the diagnosis of hepatorenal syndrome. For example, urinary volume is usually <500 mL/day, but there are nonoliguric forms of hepatorenal syndrome. Urinary sodium excretion is usually <10 mEq/day in hepatorenal syndrome. However, cases of well-documented hepatorenal syndrome with urinary sodium of >10 mEq/day have been reported. Finally, although the urinary osmolality is higher than the plasma osmolality in most patients with hepatorenal syndrome, a decrease in urinary osmolality may occur as renal failure progresses.
Table 10–1. Diagnostic Criteria for Hepatorenal Syndrome. |Favorite Table|Download (.pdf)
Table 10–1. Diagnostic Criteria for Hepatorenal Syndrome.
Cirrhosis with ascites
Serum creatinine >133 μmol/L (1.5 mg/dL)
No improvement of serum creatinine (decrease to a level of ≤133 μmol/L) after at least 2 days of diuretic withdrawal and volume expansion with albumin; the recommended dose of albumin is 1 g/kg body weight/day up to a maximum of 100 g/day
Absence of shock
No current or recent treatment with nephrotoxic drugs
Absence of parenchymal kidney disease as indicated by proteinuria >500 mg/day, microhematuria (>50 red blood cells per high power field), and/or abnormal renal ultrasonography
The Internal Ascites Club divided hepatorenal syndrome into type 1 and type 2. Type 1 hepatorenal syndrome is characterized by a rapid decline in renal function defined as a doubling of serum creatinine to a level greater than 220 μmol/L or a halving of the creatinine clearance ...