Upright posture blunts postprandial splanchnic hyperemia in patients with cirrhosis and portal hypertension

The aim of this study was to compare postprandial hemodynamic changes obser ved during assumption of the recumbent posture and upright posture in patie nts with cirrhosis and portal hypertension. Eleven patients with cirrhosis and portal hypertension were studied. Echo-Doppler examinations were perfor med to measure flow volume in the portal vein (PV), superior mesenteric art ery (SMA), and splenic artery (SA) in the fasting condition. Collateral blo od flow was indirectly calculated by determining the difference between the sum of SMA, SA, and PV blood flows. After these measurements were done, ea ch patient received a standardized liquid meal and was then randomly assign ed to either maintain supine or upright posture, in a crossover design, on 2 different days (recumbent day and upright day). On each study day, the ab ove-mentioned measurements were repeated 30 min and 60 min after the meal. PV blood flow increased significantly after the meal on the recumbent day ( P < 0.01) but not on the upright day (P = 0.78). Although there were signif icant postprandial increases in SMA blood flow on both study days (P < 0.01 , P < 0.01), the effect was less pronounced on the upright day than on the recumbent day (P < 0.01). Postprandial SA blood flow showed no change on th e recumbent day (P = 0.63), but decreased significantly on the upright day (P < 0.01). The calculated postprandial collateral blood Bow increased sign ificantly on the recumbent day (P < 0.05), but showed no change on the upri ght day (P = 0.53). These results suggest that the upright posture blunts p ostprandial splanchnic hyperemia in patients with cirrhosis and portal hype rtension.