ACUTE EFFECT OF LOW-DOSE THEOPHYLLINE ON THE CIRCULATORY DISTURBANCESOF CIRRHOSIS

Background-Adenosine is a potent vasoactive substance that may be resp onsible for mediating the altered haemodynamics found in patients with cirrhosis. Aim The administration of oral theophylline was used to in vestigate the effect of adenosine receptor antagonism upon the circula tion of patients with cirrhosis. Methods-Twenty eight patients were gi ven oral theophylline and intravascular haemodynamic measurements obta ined over approximately one hour. Results-After 240 mg of oral theophy lline elixir the hepatic venous pressure gradient mean fell from 21.8 (2.1) to 19.9 (2.4) mm Hg (p<0.01), and azygos blood flow fell from 48 1 (94) to 375 (83) ml/min (p<0.05). There were no changes in cardiac o utput or systemic vascular resistance despite a fall in mean arterial pressure (92.2 (2.0) to 89.2 (1.8) mm Hg; p<0.05) and a rise in heart rate (78.3 (3.0) to 82.4 (3.2); p<0.001). Left renal vein flow measure d by a reverse thermodilution catheter rose from 387 (91) to 601 (119) ml/min (p<0.05). The proportion of cardiac output perfusing the left kidney rose from 5.0 (1.3) to 9.7 (2.8)%. Conclusions-These changes in dicate a significant role for adenosine in the renal vasoconstriction and a more minor role in the maintenance of portal hypertension.