Purpose: To establish normal gallbladder ejection fraction (GBEF) values for two sincalide (cholecystokinin [CCK]) infusion dose rates, 0.01 microg per kilogram of body weight infused for 3 minutes and 0.01 microg/kg infused for 60 minutes.
Materials and methods: Twenty healthy subjects were examined. GBEFs were calculated for the 3-minute infusion and for each 15-minute interval for the 60-minute infusion. Normal values were determined by using the mean +/- 2 SDs and a more rigorous statistical analysis.
Results: With the 3-minute infusion, GBEFs were significantly more variable than with the 45- and 60-minute values for the 60-minute infusion (P < .01, .002). With intervals including 95% of the population, the GBEF lower normal range was 16.8% for the 3-minute infusion but 31% and 41% for the 45- and 60-minute values, respectively. GBEFs of less than 35% were noted in six (30%) of 20 healthy subjects with the 3-minute infusion but in only one with the 60-minute infusion. Hepatobiliary ultrasonography was performed in six of seven subjects with GBEF of 36% or less, and US findings in all six were normal.
Conclusion: A 3-minute infusion of sincalide, 0.01 microg/kg, produces too variable a GBEF response to establish a clinically useful normal range. With 0.01 microg/kg infused for 60 minutes, clinically useful normal values were established at 45 and 60 minutes.