Local deterioration of the cutaneous venoarterial reflex of the hand in cirrhosis.

Cutaneous focal blood perfusion and an index of cutaneous vascular resistance were determined on the dorsum and palm of the hand of 34 patients with liver cirrhosis and of 24 healthy control subjects. Tests were performed with a laser-Doppler technique before and during stimulation of the vasoconstrictor venoarterial reflex, performed by means of venous occlusion of the forearm. The mean arterial blood pressure of the cirrhotics turned out to be lower than that of the controls. On the dorsum of their hands a normal blood perfusion and a reduced vascular resistance were verified, suggesting the intervention of a local autoregulatory phenomenon of the blood flow. The blood perfusion turned out to be higher, whereas the vascular resistance was lower than the norm on the palm of the hands of cirrhotic patients who had palmar erythema, showing the presence of an anomalous non-autoregulatory vasodilation. The extent of venoarterial reflex on the dorsum of the hand turned out to be identical in the patients and controls, whereas that on the palm turned out depressed. This anomaly was present also in patients without palmar erythema, although less marked than in those with erythema. The data obtained suggest the presence of a disturbance in the functioning of the arteriovenous anastomoses (numerous in the palm but very scarce in the dorsum), superimposed on the venoarterial reflex. It may depend on the existence, in hepatic cirrhosis, of an impairment of the specialized autonomic nervous mechanisms that control temperature loss.