Background/aims: Albumin administration prevents renal failure and improves survival in spontaneous bacterial peritonitis. This study characterizes the mechanisms of action of albumin in this condition.
Methods: Systemic and splanchnic hemodynamics, plasma renin activity and plasma concentration of interleukin-6, serum concentration of nitric oxide and ascitic fluid levels of nitric oxide and interleukin-6 were assessed at diagnosis and resolution of infection in 12 patients with spontaneous bacterial peritonitis treated with ceftriaxone plus albumin. At infection resolution there was a significant improvement in circulatory function, as indicated by a significant increase in mean arterial pressure (+8%, P=0.02), a fall in heart rate (-10%, P=0.01), a suppression of plasma renin activity (-67%, P=0.002) and a decrease in creatinine levels. These changes were related to both an increase in cardiac work (stroke work index: +18%, P=0.005) and in peripheral vascular resistance (+14%, P=0.05). The improvement in cardiac function was due to an increase in filling. No significant changes were observed in portal pressure or hepatic blood flow.
Conclusions: These results indicate that the beneficial effects of albumin administration on systemic hemodynamics and renal function in spontaneous bacterial peritonitis are related to both an improvement in cardiac function and a decrease in the degree of arterial vasodilation.