Effect of successive swallows on oesophageal motility of normal volunteers, patients with Chagas'' disease and patients with idiopathic achalasia

Most frequently, ten swallows of a 5-mL bolus of water are performed during oesophageal manometry. Our hypothesis is that five swallows may produce the same results. We studied the oesophageal contraction parameters of 40 volunteers, 75 patients with Chagas' disease and 14 patients with idiopathic achalasia. Motility was recorded at 5, 10 and 15 cm above the lower oesophageal sphincter. The subjects performed ten swallows of a 5-mL bolus of water alternated with ten dry swallows with an interval of at least 30 s. We measured the amplitude, duration, peristaltic velocity, number of failed and number of simultaneous contractions of the initial five and final five dry and wet swallows. The comparison of dry and wet swallows showed the differences already known. The comparison of the parameters of the initial five swallows with those of the final five swallows showed no differences. Thus, when the initial five or the final five swallows were considered, there was no change in the conclusions reached by the comparison of patients and volunteers and of dry and wet swallows. We conclude that five swallows may be sufficient for the manometric examination of oesophageal parameters in Chagas' disease and idiopathic achalasia.