Sonographic comparison of gastric emptying of broth and water: is there a promoting cephalic factor?

To examine the emptying times of broth and water, and explore the possibility of a cephalic influence on gastric emptying.On different days each of twelve healthy volunteers had meals of either 350 ml water or 350 ml broth. Subsequently ten volunteers had meals of water alone and of water followed by sham feeding with broth. The antral area was determined at sonography five times before the meal as a baseline, and every 1-4 minutes after the meal. The time until the antral area had decreased to 150% of baseline (T150) was determined and used as surrogate expression of gastric emptying time.The mean T150 was for water 20.3 min (range 12-40), and was for broth significantly shorter 12.6 min (5-21), P = 0.0020. In the subsequent series the mean T150 was 28.5 min (18-49) for water, and significantly shorter for water followed by sham feeding, 22.8 (14-40), P = 0.0078.Broth empties faster from the stomach than plain water, probably because of a "cephalic phase" stimulation of gastric motility via the vagus nerve.