Positional Variation in Response to Multiple Rapid Swallows While Supine vs Sitting

Abstract

Introduction: Provocative testing with multiple rapid swallows (MRS) during high resolution esophageal manometry (HRM) has emerged as a valuable tool in the evaluation of esophageal peristaltic reserve. The goal of this study was to evaluate the consistency of the response to MRS in two different body positions, supine and sitting, and to identify any association between discordant MRS findings and Chicago Classification 3.0 (CC) diagnosis. Methods: Retrospective analysis was carried out on 100 consecutive patients undergoing HRM for any indication at a tertiary referral motility lab. Patients were first placed in the supine position and underwent ten 5mL wet swallows at 30 second intervals for baseline peristalsis and five 5mL rapid wet swallows at 2 second intervals constituting MRS. This was then repeated in the sitting position. A solid state catheter with 36 pressure sensors spaced 1cm apart (Given/Medtronic) was utilized. Analysis included LES Integrated Relaxation Pressure, Distal Latency, and Distal Contractile Integral (DCI) with characterization by CC. Augmentation of peristalsis was defined as ratio > 1 of DCI following MRS compared to the DCI of the wet swallows. Results: Twenty-five patients were excluded due to not having data in both positions (patient intolerance). Of the remaining 75, the mean age was 51.2 years, and 74% were female. 53 patients were classified as normal on CC, with 66% concordance between response to MRS in the supine and sitting position. Nine patients were classified as ineffective esophageal motility, with 44% positional concordance. The rate of failure to augment following MRS was 44% while supine and 78% while sitting. Nine patients were classified as EGJ outflow obstruction, with 44% concordance between the two positions. Eleven patients were diagnosed with achalasia, but only one tolerated MRS in both positions with concordant results. There were only a few patients with other CC diagnoses, including diffuse esophageal spasm, jackhammer esophagus, and fragmented peristalsis. Conclusion: While there was broad consistency in response to MRS in the sitting versus supine position, variation was more likely to occur when the CC diagnosis was EGJ outflow obstruction or ineffective esophageal motility, suggesting that MRS is more likely to be affected by gravity with these two underlying conditions. Patient position during HRM appears to be relevant when interpreting response to MRS.Figure 1Figure 2Figure 3