The Effect of Propofol on the Canine Sphincter of Oddi

To assess the effect of propofol on the canine sphincter of Oddi (SO), sphincter of Oddi manometry (SOM) was performed in fasting dogs which had undergone cholecystectomy and placement of modified Thomas duodenal cannulae. Using two water-perfused, single-lumen manometric catheters, SO and duodenal pressures were measured simultaneously. Baseline SO activity was recorded for at least one complete interdigestive cycle followed by bolus injections of propofol (Diprivan (®)) (N = 31) from 0.1 to 4.0 mg/kg during Phase I of the Migrating Motor Complex (MMC). When propofol was administered in bolus doses ≤ 0.5 mg/kg, no change in SO or duodenal motor function was seen. In doses ≥ 0.5 mg/kg, SO basal pressure, amplitude, and frequency of contractions increased significantly. Increases in duodenal activity paralleled SO activity. Our results suggest that propofol in low doses may be useful for sedation during Sphincter of Oddi manometry in humans. Further studies of the effects of propofol on the human sphincter of Oddi are warranted.