Role of peritoneal absorption in ascites.

The movement of water, electrolytes and protein across the peritoneum was studied experimentally and clinically in ascites. In the experimental and clinically in ascites. In the experimental studies, large amounts of solutions of various osmolar and colloid osmolar concentrations were infused rapidly into the peritoneal cavities of 32 dogs. In 26 of these dogs, the ureters were ligated before the experiment was begun; the other six dogs served as controls. The clinical studies were done in five patients with ascites. Tritium, 35S and RISA dilution techniques were used to study the kinetics of the different components of peritoneal fluid. Osmolarity changes were measured in plasma and peritoneal fluid by the freezing point depression method. Volume changes of peritoneal fluid were measured serially up to 24 hours for the assessment of the peritoneal absorption rate. The rate of fluid movement across the peritoneal membrane seems to be influenced, among others, by the composition of the intraperitoneal fluid, as well as by the properties of the membrane itself. An asymmetric pattern of peritoneal absorption rate of the different compositional elements of ascitic fluid was observed in this study which seems to interrelate with dynamic equilibrium which develops between ascites and the physiologic body fluid compartments. No cessation of peritoneal fluid absorption or a maximal reabsorption rate was observed in this study; nevertheless, variations in the rate of peritoneal absorption due to miscellaneous influences are possible.