Chronic Kidney Disease and Liver Disease

Kidney disease is a common complication in patients with liver disease. The development of kidney disease is associated with significant morbidity and mortality. The interrelationship between the kidneys and the liver is complex, as kidney failure may be functional or structural in nature. Functional renal failure is a common feature in patients with liver disease, due to underlying hepatorenal pathophysiology, marked by splanchnic vasodilation, arterial underfilling and renal vasoconstriction that progresses in patients with decompensated cirrhosis. Functional renal compromise may be further complicated by structural kidney disease associated with either primary liver or systemic disease. Aside from under recognition of decreased GFR due to inaccurate S[Cr]-based estimates, differentiating functional renal impairment from parenchymal injury is problematic. Moreover, the clinical setting of these often critically ill patients, coupled with intense renal vasoconstriction, predisposes them to many types of renal dysfunction and disease. Clinically, varying combinations of both functional and structural kidney disease characterize the spectrum of kidney disease in the patients with liver disease. Clinical status may be further understood by classifying renal failure as acute, chronic or AKI superimposed on chronic kidney disease, but determination of classifications may be indistinct.Understanding the spectrum of kidney disease in the setting of liver failure not only allows for therapy to be individualized but also provides insight regarding the reversibility of kidney disease with implications regarding liver and simultaneous liver-kidney transplantation.