Assessing Intra-Esophageal Pressure in Patients Presenting with Pulmonary Complaints Using High-Resolution Manometry Presidential Poster

Abstract

Purpose: The purpose of this study was to determine whether intra-esophageal pressure determined on high-resolution manometry is associated with abnormal pulmonary function. Methods: The Enterprise Data Warehouse (EDW) at Northwestern University identified patients who had undergone HRM and pulmonary function testing within a 6-month period. A retrospective case-control study was performed to evaluate changes in intra-esophageal pressure in patients with underlying pulmonary pathology. A group of 50 asymptomatic volunteers without esophageal dysfunction served as a control group. Intra-esophageal pressure measurements were taken at proximal (3 cm below the UES) and distal (3 cm above the LES) sites, at end-inspiration and end-expiration in the supine position. Participants were then categorized into groups based on pulmonary function testing, using American Thoracic Society guidelines. Statistical analysis using ANOVA evaluated differences in intra-esophageal pressures in patients with normal or restrictive PFTs versus asymptomatic controls. Results: Final analysis included 55 participants with normal PFTs, 55 participants with restrictive PFTs and 50 asymptomatic controls. There was a significant difference in distal esophageal end-expiratory pressure in participants who underwent pulmonary testing (normal and restrictive pulmonary function tests) in comparison to asymptomatic controls (p=7.75 × 10-24). The difference in proximal esophageal end-expiratory pressure in participants with underlying pulmonary pathology was numerically, but not statistically different (p=0.18) (Figure 1). There was a difference between proximal and distal esophageal pressures in all groups in the supine position.Figure 1: Changes in intra-esophageal pressures in individuals with pulmonary disease versus normal controls.Conclusion: Individuals presenting with pulmonary complaints had higher distal esophageal pressures when compared to asymptomatic controls, with the most pronounced difference observed in those with a restrictive pattern during the end-expiratory phase. While the exact mechanism responsible for the pressure differential observed between the proximal and distal esophagus will require further research, this finding suggests the possible influence of poor esophageal emptying or an anatomical or physiologic consequence of the pulmonary disorder as possible causes.