Peritoneal Transudate: A Diagnostic Clue to Portal System Obstruction in Patients with Intra-abdominal Neoplasms or Peritonitis

The protein content of ascitic fluid was determined in 26 patients with intra-abdominal neoplasms or inflammation in whom patency of the portal venous system was evaluated directly at laparotomy or autopsy. Ascitic fluid was high in protein content (respectively 54% and 62% of the plasma level) in both groups except when portal system occlusion was superimposed on the underlying disturbance, in which case ascitic fluid was low in protein content (respectively 8% and 24% of the plasma level). Viewed in the light of observations on the protein content of ascitic fluid in patients with hepatic cirrhosis, these data suggest that, in the absence of marked hypoproteinemia, peritoneal fluid of low protein content signifies marked impairment to portal blood flow into the liver.