[Sympathetic nervous activity in cirrhosis: the relationship between peripheral hemodynamics and renal function...

The relationship between the activity of the sympathetic nervous system and the systemic and peripheral hemodynamic and renal function changes and the antinatriuretic activity in a group of 30 cirrhotic patients and 8 healthy subjects (control group) was investigated. Plasma catecholamines (noradrenaline, adrenaline and dopamine), plasma renin activity, plasma aldosterone concentrations, mean arterial pressure, cardiac output, blood volume, right femoral arterial flow (RFAF) and renal function parameters were determined in all the participants. Cyclic GMP urinary excretion (cV-UGMP) was used as an indirect index of systemic nitric oxide production. The plasma concentration of noradrenaline was greater in the patients than in the control group and was directly correlated with other vasopressor and antinatriuretic systems, RFAF, cV-UGMP, the degree of hepatic failure studied by the Pugh score and was inversely correlated with creatinine clearance and urinary sodium excretion. On Cox regression analysis, only the RFAF, creatinine clearance and plasma adrenaline concentration remained independently associated with plasma noradrenaline levels. Furthermore, plasma noradrenaline was significantly higher in patients with greater hyperdynamic circulation. These results indicate that extrasplanchnic vasodilatation substantially contributes to sympathetic nervous hyperactivity which may significantly influence in the renal function changes observed in these patients.