Effect of somatostatin on splanchnic hemodynamics in patients with cirrhosis of the liver and in normal subjects

Abstract

The effect of somatostatin on splanchnic hemodynamics was determined in 8 patients with cirrhosis of the liver and in 18 normal subjects using arterial-hepatic-venous catheterization. Estimated hepatic blood flow determined by indocyanine green infusion was 1.36 ± 0.23 L/min (± SEM) in patients with cirrhosis and remained unaffected during 30 min of somatostatin (250 μg/h) administration. Wedged hepatic venous pressure which was elevated to 23 ± 1.8 mmHg was also uninfluenced. In contrast to somatostatin, an infusion of vasopressin (12 U/h for 30 min) given to the same patients, lowered estimated hepatic blood flow by 28% (p < 0.05) and wedged hepatic venous pressure by 18% (p < 0.02). Arterial gastrin and insulin levels were lowered during somatostatin infusion by 33% (p < 0.02) and by 75% (p < 0.005), respectively. In contrast to the cirrhotics, infusion of 250 μg/h somatostatin into normal subjects was associated with a decrease of estimated hepatic blood flow from 1.20 ± 0.16 to 0.88 ± 0.12 L/min (p < 0.01) representing a 27% decline. Arterial gastrin and insulin concentrations were lower (p < 0.01) than in cirrhotics, but the basal levels were lowered by somatostatin to a similar degree in both groups of patients. A higher dose of somatostatin (500 μg/h) administered to normal subjects resulted in a similar decrease of gastrin and of estimated hepatic blood flow as that seen with 250 μg/h, whereas a lower dose (125 μg/h) decreased gastrin but failed to influence estimated hepatic blood flow. Thus, somatostatin at a dose which has been used in the treatment of acute peptic ulcer hemorrhage (250 μg/h) failed to influence estimated hepatic blood flow and wedged hepatic venous pressure in patients with cirrhosis but lowered splanchnic blood flow in normal subjects. Assuming that this effect contributes to somatostatin's therapeutic efficacy, these results cast doubt on its potential value in the treatment of upper gastrointestinal bleeding of cirrhotics with portal hypertension.