The significance of the volume of pancreatic juice measured at secretin stimulation testing: a single-center evaluation of 224 classical secretin stimulation tests.

OBJECTIVES: (1) To quantitate volume production during secretin stimulation testing in patients suspected of having chronic pancreatitis (CP); (2) to compare volume production to clinical criteria for the diagnosis of CP. METHODS: A total of 224 patients referred for suspected CP were reviewed retrospectively for clinical information supporting the diagnosis of CP. The patients were divided into 2 groups: those with peak bicarbonate (PB) of less than 80 mEq/L and those with PB of 80 mEq/L or greater (ie, CP and no CP). For a separate comparison, the patients were also placed into similar 2 groups based on clinical criteria. The volume, total bicarbonate output, volume per kilogram, and PB of pancreatic juice after secretin stimulation in patients thought to have CP were compared to those thought not to have CP. RESULTS: Volume was lower in the patients with PB of less than 80 mEq/L (206 ± 114 and 269 ± 106 mL) and lower in patients who met clinical criteria for CP (203 ± 109 and 271 ± 108 mL), P < 0.001 for both, but there was significant overlap (volume alone did not accurately discriminate CP from no CP). CONCLUSIONS: During secretin stimulation testing, bicarbonate parameters likely are better predictors of CP than volume parameters. Changes in the production of the volume of pancreatic juice during secretin stimulation likely reflect relatively late changes in pancreatic function.