Control of ascites absorption in anesthetized cats: effects of intraperitoneal pressure, protein, and furosemide diuresis.

There is considerable evidence that fluids are removed from the peritoneal cavity by drainage into lymphatics lining the surface of the diaphragm, but there is little quantitative information on the rate of reabsorption as affected by conditions which exist in cirrhotic ascites. In the present study a plethysmographic technique was utilized to record the rate of absorption of fluid from the peritoneal cavity of anesthetized cats. The results of studies in 33 cats showed that the rate of fluid absorption from the peritoneal cavity was directly proportional to the intraperitoneal pressure regardless of whether the intraperitoneal fluid was free from protein or contained a protein concentration equivalent to that of plasma. Fluid was absorbed with a protein concentration equivalent to that present in the peritoneal cavity. Thus it is apparent that the intraperitoneal pressure is an important factor controlling the accumulation of ascitic fluid but the protein concentration of the intraperitoneal fluid does not affect the rate of reabsorption. In addition, marked diuresis induced by intravenous furosemide does not appear to mobilize ascites by an effect on the reabsorption process.