Abstract:

Objective

To analyze the differences in high-resolution esophageal manometry （HREM）results between side-lying position and supine position.

Methods

A total of 137 patients with the symptoms of gastroesophageal reflux disease （GERD） such as heartburn, acid reflux, chest pain, and food regurgitation,who visited the department of gastroenterology at Xuanwu Traditional Chinese Medicine Hospital in Beijing from November 2019 to December 2022 were included in this study. were tested for HREM in a lateral position first, followed by a supine position, and then the similarities and differences in HREM results between the two positions were analyzed.

Results

The average residual pressure of the upper esophageal sphincter （UES） in side-lying position were significantly lower than those in supine position （P＜0.05）, but no statistically significant difference was found in the resting pressure and peak pressure of UES （P＞0.05）.Except of the average peak value and initial velocity of esophageal peristalsis in side-lying position were significantly lower than those in supine position （P＜0.001）, other parameters of the esophageal body in two positions （P＜0.05） were not different from each other in statistics. The length of the esophagus and the distance from the lower esophageal sphincter （LES） to the nasal cavity measured in side-lying position were significantly longer than those in supine position （P＜0.05）, and the resting pressure of LES was significantly lower than that in the supine position （P＜0.05）. However, differences with regard to the residual LES pressure between side-lying position and supine position （P＞0.05） were not significant. When lying on the side position, the distal contractile integral and maximum pressure inside the food mass were significantly lower than those in the supine position （P＜0.05）, but there was no significant difference in contractile front velocity （P＞0.05）. According to the Chicago classification analysis, except for a significantly higher percentage of small peristalsis interruption in side-lying position compared to supine position （P＜0.05）, there was no statistically significant difference in all other analysis parameters compared to supine position （P＞0.05）, as well as the final diagnosis for esophageal motor abnormality.

Conclusions

Although there were some differences in parameters of esophageal pressure measurement between side-lying and supine position, the degree of LES relaxation achieved after swallowing was consistent, as well as the integrity of peristaltic waves. There had no significant impact on the final diagnosis of esophageal pressure measurement, and the Chicago classification.

Key words: Gastroesophageal reflux disease, High-resolution esophageal manometry, Body position, Lower esophageal sphincter