The integrated relaxation pressure may not be an appropriate gold standard for deglutitive relaxation due to reliance on a single intragastric reference sensor.

BACKGROUND: Integrated relaxation pressure (IRP) calculation depends on the selection of a single gastric reference sensor. Variable gastric pressure readings due to sensor selection can lead to diagnostic uncertainty. This study aimed to examine the effect of gastric reference sensor selection on IRP measurement and diagnosis. METHODS: We identified high-resolution manometry (HRM) conducted between January and November 2017 with at least six intragastric reference sensors. IRP measurements and Chicago Classification 3.0 (CCv3) diagnoses were obtained for each of six gastric reference sensors. Studies were categorized as "stable" (no change in diagnosis) or "variable" (change in diagnosis with gastric reference selection). Variable diagnoses were further divided into "variable normal/dysmotility" (≥1 normal IRP measurement and ≥1 CCv3 diagnosis), or "variable dysmotility" (≥1 CCv3 diagnosis, only elevated IRP measurements). Bland-Altman plots were used to compare IRP measurements within HRM studies. KEY RESULTS: The analysis included 100 HRM studies, among which 18% had variable normal/dysmotility, and 10% had variable dysmotility. The average IRP difference between reference sensors was 6.7 mmHg for variable normal/dysmotility and 5.9 mmHg for variable dysmotility. The average difference between the proximal-most and distal-most sensors was -1.52 mmHg (lower limit of agreement -10.03 mmHg, upper limit of agreement 7.00 mmHg). CONCLUSIONS & INFERENCES: IRP values can vary greatly depending on the reference sensor used, leading to inconsistent diagnoses in 28% of HRM studies. Choosing the correct gastric reference sensor is crucial for accurate test results and avoiding misdiagnosis. Standardization of reference sensor selection or supportive testing for uncertain results should be considered.

Baseline impedance via manometry and ambulatory reflux testing are not equivalent when utilized in the evaluation of potential extra-esophageal gastroesophageal reflux disease.

BACKGROUND: Esophageal baseline impedance (BI) shows promise for the diagnosis of gastroesophageal reflux disease (GERD), but means of acquisition and relevance to extra-esophageal manifestations of GERD (EE-GERD) remain unclear. In this study we aim to (I) evaluate concordance between BI as measured by 24-hour pH-impedance (pH-MII) and high-resolution impedance manometry (HRIM), and (II) assess relationship to potential EE-GERD symptoms. METHODS: In this prospective open cohort study, patients presenting for outpatient HRIM and pH-MII studies were prospectively enrolled. All patients completed the GERD-HRQL, NOSE, and respiratory symptom index questionnaire (RSI), plus questions regarding wheezing and dental procedures. HRIM and pH-MII were evaluated with calculation of BI. Correlations were assessed using either Pearson's correlation or Spearman's rank coefficients. RESULTS: 70 HRIM patients were enrolled, 35 of whom underwent pH-MII. There was no correlation between BI measurements as assessed by HRIM and pH-MII proximally, but there was moderate-weak correlation distally (r=0.34 to 0.5). Distal acid exposure time correlated with distal BI only for measurements by pH-MII (rho= -0.5 to -0.65), and not by HRIM. There was no relationship between proximal acid exposure time and proximal BI. There were no correlations when comparing proximal or distal BI measurements, acid exposure times, and impedance events to symptoms. CONCLUSIONS: Concordance between BI as measured by HRIM and pH-MII is poor, especially proximally, suggesting that these two methods are not interchangeable. There is no correlation between BI both distally/proximally and symptoms of either GERD/EE-GERD, suggesting that many symptoms are unrelated to acid or that BI is not an adequate marker to assess EE-GERD symptoms.

A Positive Correlation Between Gastric and Esophageal Dysmotility Suggests Common Causality.

BACKGROUND: Gastric and esophageal dysmotility syndromes are some of the most common motility diagnoses, but little is known about their interrelationship. AIMS: The aim of our study was to determine if a correlation exists between gastric and esophageal dysmotility syndromes. METHODS: We reviewed the records of all patients who underwent both solid gastric emptying scintigraphy (GES) and high-resolution esophageal manometry (HRM) within a 2 year period, with both done between August 2012 and August 2017. All GESs were classified as either rapid, normal, or delayed. All HRMs were classified according to the Chicago Classification 3.0. Correlations were assessed using Fisher's exact test and multiple logistic regression. RESULTS: In total, 482 patients met inclusion criteria. Of patients with a normal, delayed, and rapid GES, 53.1, 64.5, and 77.3% had an abnormal HRM, respectively (p < 0.05 vs. normal GES). Likewise, patients with an abnormal HRM were more likely to have an abnormal GES (54.9 vs. 41.8%, p = 0.005). Multiple logistic regression showed abnormal GES [odds ratio (OR) 2.14], age (OR 1.013), scleroderma (OR 6.29), and dysphagia (OR 2.63) were independent predictors of an abnormal HRM. Likewise, an abnormal HRM (OR 2.11), diabetes (OR 1.85), heart or lung transplantation (OR 2.61), and autonomic dysfunction (OR 2.37) were independent predictors of an abnormal GES. CONCLUSIONS: The correlation between an abnormal GES and HRM argues for common pathogenic mechanisms of these motility disorders, and possibly common future treatment options. Clinicians should have a high index of suspicion for another motility disorder if one is present.

Baclofen and gastroesophageal reflux disease: seeing the forest through the trees.

Baclofen has been shown to decrease reflux events and increase lower esophageal sphincter pressure, yet has never established a clear role in the treatment of gastroesophageal reflux disease (GERD). Lei and colleagues have shown in a recent elegant study that baclofen reduces the frequency and initiation of secondary peristalsis and heightens esophageal sensitivity to capsaicin-mediated stimulation. These findings may help explain both the benefit of baclofen in conditions such as rumination and supragastric belching, as well as the apparent lack of benefit of baclofen and other GABAB agonists in long-term treatment of GERD.