Intramucosal acidosis and the inflammatory response in acute pancreatitis

OBJECTIVE: The:aim of this study was to assess the host response and dimini shed bowel perfusion during acute pancreatitis. METHODS: A total of 19 patients admitted with established diagnoses of acut e pancreatitis on the basis of clinical findings, elevated serum amylase to more than four times the upper limit or by contrast radiology. Patients we re stratified into mild and Severe pancreatitis using the Atlanta criteria. Blood samples were obtained from in-dwelling lines or direct venipuncture within 12 h of admission and 24 hourly thereafter-for measurements of plasm a endotoxin, EndoCab immunoglobulin (Ig)G and IgM antibodies, tumor necrosi s factor (TNF), p55 TNF receptor, and IL-6. A gastric tonometer was inserte d in place of a nasogastric tube for intramucosal pH evaluation. RESULTS: Episodes of endotoxaemia were more common and endotoxin concentrat ion significantly higher at presentation in the severe group compared to th e mild group of patients. A greater consumption of IgM antibody was found i n those with severe disease. The decrease in IgM antibody concentration was shown to be a specific host response, as a fall in concentration of antibo dies to a neutral antigen, tetanus toroid, was not observed. Significantly greater elevations:were found in p55 TNF receptor and IL-6 concentrations,i n the severe group in comparison to those suffering mild pancreatitis. Sign ificant correlations were found between gastric:intramucosal pH and EndoCab IgM antibody, p55 TNF receptor, and IL-6. CONCLUSIONS: These results suggest that endotoxemia, an acute inflammatory response, and a reduction in bowel perfusion: may Occur in severe acute pan creatitis. The endotoxemia and inflammatory response may be due to the perm eation of bacteria and their breakdown products across a disrupted bowel mu cosal barrier. (Am J Gastroenterol 1999;94:2423-2429, (C) 1999 by Am. Coll. of Gastroenterology).