P0290 - Effects of Body Position on High-Resolution Manometry Data and Chicago Classification Diagnosis

Janelle Gyorffy, MD, Brandon Kuiper, MD, Amy Stratton, DO
San Antonio Uniformed Services Health Education Consortium, Fort Sam Houston, TX

Introduction: Supine position is the standard for performing high-resolution manometry (HRM). However, this is often poorly tolerated and does not simulate real world positioning. This study evaluated HRM in the supine, 45-degree, and upright (90-degree) positions to determine if there was a significant positional difference in measurements and final esophageal motility diagnoses.

Methods: Twenty-seven patients (ages 30-67 years, 63% female) with no known esophageal motility disorder underwent HRM for evaluation of various esophageal symptoms. The lower esophageal sphincter (LES) resting pressure, integrated relaxation pressure (IRP), distal contractile integral (DCI), amplitude, distal latency (DL), and number of intact/weak/failed/hypercontractile/premature swallows were measured for each patient in the supine, 45-degree, and upright positions. Esophageal motility patterns were determined per Chicago classification version 3.0.

Results: LES pressures were significantly lower in the upright position compared to supine but lacked difference at 45-degrees. The IRP was significantly lower in the upright position compared to supine and 45-degrees. The upright DCI was significantly lower compared to supine but not 45-degrees. There were significantly fewer intact swallows in the upright position compared to supine and 45-degrees but no difference in failed swallows. Esophagogastric junction outflow obstruction (EGJOO) resolved in the upright position in 7 of 11 patients with EGJOO in the supine/45-degree positions, which trended toward statistical significance. Overall, position did not significantly change motility diagnosis.

Discussion: Systematic reviews analyzing supine and upright positioning in HRM have largely been inconclusive. Although position did not alter diagnoses, LES resting pressure and IRP were significantly lower in the upright position. Though limited by small sample size, the results suggest that the 45-degree position provides similar measurements to supine with associated decrease in vascular artifact, implying that HRM can be performed accurately with partial head elevation. This study echoes Chicago classification version 4.0 guidance to perform assessment in two positions for diagnosis of EGJOO. Further studies are needed to confirm HRM protocols using the 45-degree and upright positions, rather than supine positioning, to determine the accuracy in diagnosis of esophageal motility disorders while improving patient comfort and decreasing aspiration risk.

Comparison of positions	LES (mmHg)	IRP (mmHg)	DCI (mmHg·s·cm)	DL (s)	Amplitude (mmHg)	Intact swallows	Weak Swallows	Failed Swallows
Supine position vs Upright position	30.1	12.9	1870.6	7.1	84.7	7.6	0.9	1.6
	24.2 (p=0.03)	9.5 (p< 0.01)	1117.4 (p< 0.01)	6.6 (p=0.03)	63.3 (p< 0.01)	4.8 (p< 0.01)	2.6 (p=0.02)	2.1 (p=0.5)
Supine position vs 45-degree	30.1	12.9	1870.6	7.1	84.7	7.6	0.9	1.6
	29.2 (p=0.9)	12.8 (p=0.9)	1354.9 (p< 0.01)	6.8 (p=0.3)	68.8 (p< 0.01)	6.6 (p=0.2)	1.5 (p=0.6)	1.7 (p=0.6)
45-degree vs Upright position	29.2	12.8	1354.9	6.8	68.8	6.6	1.5	1.7
	24.2 (p=0.09)	9.5 (p< 0.01)	1117.4 (p=0.3)	6.6 (p=0.5)	63.3 (p=0.5)	4.7 (p< 0.01)	2.6 (p=0.2)	2.1 (p=0.9)

Table: Table 1: Comparison of HRM measurements in patients in the supine, 45-degree, or upright position. Values are expressed as means. P < 0.05 indicates statistical significance. LES= lower esophageal sphincter, IRP= integrated relaxation pressure, DCI= distal contractile integral, DL= distal latency.


Disclosures:
Janelle Gyorffy indicated no relevant financial relationships.
Brandon Kuiper indicated no relevant financial relationships.
Amy Stratton indicated no relevant financial relationships.


Janelle Gyorffy, MD, Brandon Kuiper, MD, Amy Stratton, DO. P0290 - Effects of Body Position on High-Resolution Manometry Data and Chicago Classification Diagnosis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.