Catecholamines in plasma from artery, cubital vein, and femoral vein in patients with cirrhosis. Significance of sampling site.

The concentration of noradrenaline (NA) and adrenaline (A) was measured in arterial, cubital venous and femoral venous plasma in order to determine possible differences in different vascular beds in the peripheral circulation. In patients with cirrhosis, arterial plasma NA (median 2.54 nmol/l, n = 40) was significantly increased compared to controls (median 1.42 nmol/l, n = 17, p less than 0.001). Arterial plasma A was not significantly different (0.41 vs. 0.38 nmol/l). Cubital and femoral venous NA and A were positively correlated to the arterial values in both cirrhosis and controls (r = 0.86 to 0.97, p less than 0.01). In cirrhosis, median cubital venous:arterial NA ratio was significantly above unity (1.14, n = 36, p less than 0.001) as compared to unity in controls (1.00, n = 8), whereas the femoral venous:arterial NA ratio was similar in cirrhosis and controls, and significantly below unity (median 0.86 and 0.87). Cubital venous:arterial and femoral venous:arterial A ratios were significantly below unity in cirrhosis as well as in controls. The results point towards an enhanced sympathetic nervous activity in cirrhosis which may involve, among other organs, the upper limb (especially the skin of forearm and hand). To assess circulating levels of catecholamines, the importance of arterial sampling is stressed as peripheral venous samples may also reflect local factors.