Capillary Blood Flow to the Skin of Forearm in Cirrhosis

In liver cirrhosis a hyperkinetic circulatory state is frequently observed as a consequence of an arterial or even a venous peripheral vasodilatation with sec ondary increase in cardiac output. Indirect evidence suggests that, in liver dis ease, the manifestation of warm hands, capillary pulsation, or palmar erythema may also relate to such a state by way of an increased skin blood flow. The purpose of the present study has been to directly assess capillary skin blood flow in liver disease through the clearance of a locally injected radioactive substance. The study was performed in 24 patients with different liver diseases, includ ing 14 Child class II cirrhotics, and in 9 control subjects. A small volume of Na 131I solution was injected at the volar surface of the forearm, and radioactive counts were recorded continuously for ten seconds every minute for up to twenty minutes. The best fit line of the disappearance rate was determined by the least square method, and both its T/2 and an estimated blood flow parame ter were calculated. The T/2 of isotope disappearance rate was 4.54±0.71 and 4.38±0.68 minutes in cirrhotics and controls, respectively. Similarly, estimates of skin blood flow (mL/min/100 g tissue) were 7.82±1.28 in the cirrhotic pa tients, not significantly different from those in both patients with mixed liver diseases (7.6±2.86) and control subjects (8.06 ± 1.04). Parameters of skin blood flow were also invariant in respect to the various etiologies of liver disease. Thus, the present findings indicate that capillary skin blood flow is not af fected by the hyperdynamic circulatory changes occurring in liver cirrhosis. Likely, such changes mostly relate to more proximal circulatory variations oc curring at the level of arteriovenous anastomoses.