Nitric oxide and renal function in cirrhotic patients with ascites: from physiopathology to practice

Patients with cirrhosis and ascites show systemic and splanchnic arterial vasodilation, which causes a reduction in effective arterial blood volume and the activation of hormonal anti-natriuretic systems. Renal impairment is the most important predictor of hospital mortality in cirrhotic patients with SBP. In patients with SBP, the inflammatory response to the infection (TNF-alpha, IL-6) may be an important mechanism of renal dysfunction. Ascitic-fluid NO metabolites are related independently to the development of renal impairment. Treatment of SBP with intravenous albumin in addition to cefotaxime prevents renal impairment and reduces mortality in comparison with treatment with cefotaxime alone. As soon as ascites develops, liver transplantation should be considered in eligible patients, especially when local mean waiting times exceed life expectancy. Nitric oxide (NO), tumour necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) have been implicated in the pathogenesis of circulatory alterations observed in cirrhotic patients with ascites. Kidney failure is one of the main factors associated with mortality in patients with end-stage liver disease developing complications, particularly severe infections and variceal haemorrhage. Renal impairment occurs in patients with the highest concentration of cytokines in plasma and ascitic fluid and is associated with marked activation of the renin-angiotensin system. In patients with spontaneous bacterial peritonitis (SBP), serum and ascitic fluid levels of NO metabolites (nitrites and nitrates) were higher than those of patients with sterile ascites, and renal impairment is considered to be caused by a decrease in effective arterial blood volume as a result of the infection. The administration of albumin prevents deterioration of renal function and reduces mortality in these patients. However, SBP and renal dysfunction are late complications in the course of liver cirrhosis. As soon as ascites develops, liver transplantation should be considered in eligible patients, especially when local mean waiting times exceed life expectancy. A better knowledge of metabolic disorders associated with the early stage of cirrhosis is essential for the development of optimal therapeutic strategies for the prophylaxis and treatment of portal hypertension and its complications.