ASCITIC FLUID ALBUMIN AND WATER FLOWS IN PATIENTS WITH ALCOHOLIC CIRRHOSIS - EFFECTS OF PERITONEOVENOUS SHUNTING

Ascites labeled albumin and water kinetics were studied at steady stat e by intercompartmental clearances in cirrhotic patients whose ascites volumes ranged from 6.4 to 25.2 L. In 20 patients mean (+/-SD) asciti c fluid albumin clearance (equivalent to lymphatic absorption) was 3.5 +/- 1.9 L/day. In seven of them, lymphatic absorption was 3.4 +/- 0.8 L/day, total water absorption from ascitic fluid (outflow equals infl ow at steady state) was 125.8 +/- 21.5 L/day. Vascular capillary water absorption (total minus lymphatic) was 122.4 +/- 21.4 L per 24 hours. Lymphatic absorption was less than 4% of total but accounted for all albumin absorbed (13.2 +/- 6.2 gm/day). Maximum lymphatic absorption w as less than 10 L per 24 hours; peritoneovenous shunting augmented thi s function. Mean inflow water albumin concentration was 0.11 +/- 0.06 gm/L. If plasma albumin were diluted to concentration in ascites, calc ulated water inflow required would be 2.82 L/day. Actual inflow was 47 times that required. The major volume outflow path was through perito neal venous capillaries; water and small-radius solute absorption thro ugh peritoneal venous capillaries; water and small-radius solute absor ption through this route increased inflow water albumin concentration to ascites level. Concurrently, whole ascitic fluid was absorbed witho ut sieving through lymphatics. Observed ascites albumin concentration in subjects with advanced cirrhosis was produced by water absorption f rom a large volume of dilute solution rather than dilution of a small inflow volume, in which albumin concentration originally was hyperonco tic to ascitic fluid. Large-volume transperitoneal water diversion fro m sources in high-pressure, extrahepatic splanchnic capillaries to abs orption through parietal nonportal, low-pressure, peritoneal venous ca pillaries would significantly reduce portal plasma flow into liver and have deleterious systemic hemodynamic consequences.