Abstract
Abstract Purpose: To registrate the oscillations of the pH probe in the esophagus during phonation and swallowing in the erect and supine positions. Material and Method: Sixty-seven patients with suspicion of gastroesophageal reflux disease underwent manometry, 24-h pH monitoring, and videoradiography. In 43 patients the effect of dry, wet, and solid swallows in the erect and supine positions was determined, making a total of 258 swallows. In another 24 patients the effect of pH probe movement during phonation was studied. Results: During every swallow the probe moved in the proximal direction from 0.5 to 2.0 cm, returned to baseline, and in 48 swallows an additional descendent movement of up to 2.0 cm was seen, the last mentioned more pronounced during solid swallows. In the erect position, no significant difference was observed for the different swallowing types, whereas in the supine position, movements were significantly more pronounced during solid food swallows. During phonation the pH probe only ascended and returned to the baseline, with no descending part. Conclusion: The pH probe movements are dependent on body position, bolus size, bolus composition, and talking. The ascending movements can only partially compensate for the esophageal shortening during swallow because of the time difference, and could perhaps explain the variation in results and reproducibility of 24-h pH monitoring.