The value of a modified
fluorescein dilaurate (FDL) serum test for the detection of pancreatic exocrine insufficiency was investigated in 89 patients with and without
pancreatic disease. This test modification with
fluorescein serum determination following
metoclopramide (10 mg) and
secretin (1 U/kg) i.v. injection appeared efficacious in a pilot study in six healthy volunteers. Individual peak
fluorescein serum concentration was achieved within 180 min after the test meal in 96% of all subjects studied. Peak
fluorescein serum concentration within this time period allowed the best discrimination between normal and abnormal pancreatic function. Sensitivity in detection of
chronic pancreatitis was 86% (38 of 44 patients) when the lower normal
fluorescein serum concentration was considered 4.5 micrograms/ml (this value corresponds to mean - 2 SD). The specificity of this test in detecting
chronic pancreatitis was 100% when healthy controls were considered, but fell to 78% when patients with different
gastrointestinal disorders, including those with secondary
pancreatic insufficiency, were included. The correlation between serum and urinary
fluorescein determination was significant (r = 0.61; p less than 0.01). Duodenal
bicarbonate output/h after
secretin also showed a significant correlation with peak
fluorescein serum concentration (r = 0.79; p less than 0.001).