What is the hepatorenal syndrome? List causes, mechanism, diagnosis and treatment
The hepatorenal syndrome is defmed as profound oliguria and avid sodium retention in the setting of severe liver dysfunction.
Can occur in the setting of both acute and acute-on-chronic liver disease of almost any cause
eg. hepatitis, gestational liver failure, cirrl:tosis.
The pathogenesis appears to be purely functional in that recovery:of :liver function or-·
transplantation of the failing kidney leads to recovery of ·renal ·function. Mechanisms··· implicated include: hyperdynamic· circulation with lowering of renal perfusion pressure, activation of the sympathetic nervous system and a combination of precapillary vasoconstriction and past capillary dilatation by vasoactive mediators leading to decreased glomerular ultrafiltration coefficient. Hypovolaemia and raised intra abdominal pressure from ascites may also be factors.
Is based on history (deteriorating renal function in the presence of severe liver disease) and the combination of avid sodiwn retention (UNa <30mmolll), oliguria, unremarkable urinalysis and sediment, absence of obstruction and exclusion of intravascular volume depletion.
Classic teaching is that. in the absence of liver function recovery or liver transplantation,
there is no treatment other than renal replacement therapy for established hepatorenal
syndrome. Other measures to be considered or experimental are:
• Volume expansion and albumin infusion
• Relief of portal hypertension (TIPS, shunt)
• Vasopressin analogs (omipressin), experimental
• Prostaglandin analogs -experimental
Briefly, what is hepatorenal syndrome
Hepatorenal syndrome is kidney injury as the consequence of gradually reducing renal blood flow, in the context of gradually worsening liver failure.
Mechanism of hepatorenal syndrome
- Worsening hepatic function leads to worsening peripheral arterial vasodilation
- Vasodilation leads to increased cardiac output, renin-angiotensin-aldosterone overactivity, and sympathetic overactivity
- As a result, renal arterial vascular resistance increases in proportion to splanchnic and systemic arterial vasodilation
- This, there is progressive renal vasoconstriction and thus decreased glomerular filtration.
- In addition to this, worsening hepatic failure results in increasing ascites pressure (and thus decreasing renal perfusion pressure)
Causes of hepatorenal syndrome
- Sepsis of any origin
- Nephrotixic drugs in a patient with cirrhosis, particularly NSAIDs
- Rapid diuresis
- GI bleeding
- This is a diagnosis of exclusion. The following criteria apply:
- presence of liver disease and portal hypertension
- increase in creatinine to over 133micromol/L
- no other obvious cause of renal failure
- no microscopic hematuria
- no reponse to fluid challenge (i.e. no pre-renal failure)
Treatment of hepatorenal syndrome
- Albumin and fluid resuscitation
if all else fails, TIPS procedure may be appropriate.
UpToDate has an excellent synopsis of hepatorenal syndrome.
However, if you are cheap, you need free articles.
Salerno, Francesco, et al. "Diagnosis, prevention and treatment of hepatorenal syndrome in cirrhosis." Postgraduate medical journal 84.998 (2008): 662-670.
Solà, Elsa, Mónica Guevara, and Pere Ginès. "Current treatment strategies for hepatorenal syndrome." Clinical Liver Disease 2.3 (2013): 136-139.