Acute effect of low dose theophylline on the circulatory disturbances of cirrhosis.

Abstract

Adenosine is a potent vasoactive substance that may be responsible for mediating the altered haemodynamics found in patients with cirrhosis. The administration of oral theophylline was used to investigate the effect of adenosine receptor antagonism upon the circulation of patients with cirrhosis. Twenty eight patients were given oral theophylline and intravascular haemodynamic measurements obtained over approximately one hour. After 240 mg of oral theophylline 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 481 (94) to 375 (83) ml/min (p < 0.05). There were no changes in cardiac output 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 measured 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)%. These changes indicate a significant role for adenosine in the renal vasoconstriction and a more minor role in the maintenance of portal hypertension.