Evaluating the impact of position, volume, and consistency on high-resolution esophageal manometry outcomes

BackgroundThe Chicago classification primarily utilizes ten 5 mL liquid swallows in a supine position as the standard high-resolution esophageal manometry (HRM) protocol. HRM can be performed with varying volumes and consistencies and in an upright position. We aimed to determine the impact on HRM results by (1) position, (2) swallows of differing volume and consistency, and (3) perception of bolus passage. MethodsHRM was performed in healthy volunteers (HV) with the following protocol of swallows: liquids 10 x 5 mL, 5 x 10 mL, and 3 x 10 mL multiple rapid swallows; applesauce 5 x 5 mL and 5 x 10 mL; and bread 5 x 2 x 2 cm and 5 x 4 x 4cm. HV rated difficulty of each swallow on a 5-point Likert scale. All HVs performed the protocol in supine position first and then in semi-upright (sitting 70 degrees in a bed) and upright (sitting in a chair) in a randomized order. Key ResultsThirty-seven HVs, median age 27 years, 64% female completed this study. Median distal contractile integral (DCI) and integrated relaxation pressure 4 s (IRP4) of 5 mL liquid swallows significantly differed (all p < 0.01) between position performed. Large volume swallows resulted in higher DCI and lower IRP4. IRP4 results were significantly increased for 2 x 2 cm pieces of bread compared to 5 mL water swallows. DCI results were higher for 2 x 2 cm pieces of bread compared to 5 mL water swallows. Distal latency was shorter in more upright positions. Among this cohort of HV, perceived difficulty of bolus passage was more likely to occur with solid boluses. Conclusions and InferencesThe volume and consistency of a swallow and the position it is performed in, significantly alter HRM metrics. Interpretation of HRM studies should incorporate different normative values which are specific to the position and bolus type.

Automated summary

This study aimed to investigate the impact of position, different volumes and consistencies of swallows, and perception of bolus passage on high-resolution esophageal manometry (HRM) metrics. The results showed significant differences in HRM metrics with different positions, volumes, and consistencies of swallows. Interpretation of HRM studies should consider normative values specific to position and bolus type.