Normal gallbladder ejection fraction after morphine augmentation

Purpose: Morphine sulfate causes spasm of the sphincter of Oddi. Conversely, the cholecystagogue sincalide produces relaxation of the sphincter and contraction of the gallbladder. This prospective study evaluated whether sincalide could produce normal gallbladder emptying after low-dose morphine sulfate (0.04 mg/kg). Methods: Thirty to 120 minutes (mean, 51 minutes) after morphine sulfate-augmented gallbladder visualization, 25 gallbladder ejection fractions in 24 patients were measured. One patient was studied twice, 2 weeks apart. Gallbladder ejection fractions were calculated after controlled 30-minute infusions of sincalide (0.02 μg/kg). Results: Fourteen gallbladder ejection fractions were normal (mean, 63%; range, 45% to 80%) and 11 gallbladder ejection fractions were abnormal (mean, 12%; range, 5% to 19%; P < 0.001). Conclusions: Normal gallbladder ejection fractions can be obtained as early as 30 minutes after administration of low-dose morphine sulfate. Potential applications of post-morphine sulfate sincalide challenge would include, for example, to support true-negative morphine sulfate- augmented gallbladder visualization in a patient with a high clinically indicated potential of having acute cholecystitis.