Validated Clinical Score to Predict Gastroesophageal Reflux in Patients With Chronic Laryngeal Symptoms: COuGH RefluX.

BACKGROUND & AIMS: Discerning whether laryngeal symptoms result from gastroesophageal reflux is clinically challenging and a reliable tool to stratify patients is needed. We aimed to develop and validate a model to predict the likelihood of gastroesophageal reflux disease (GERD) among patients with chronic laryngeal symptoms. METHODS: This multicenter international study collected data from adults with chronic laryngeal symptoms who underwent objective testing (upper gastrointestinal endoscopy and/or ambulatory reflux monitoring) between March 2018 and May 2023. The training phase identified a model with optimal receiver operating characteristic curves, and ß coefficients informed a weighted model. The validation phase assessed performance characteristics of the weighted model. RESULTS: A total of 856 adults, 304 in the training cohort and 552 in the validation cohort, were included. In the training phase, the optimal predictive model (area under the curve, 0.68; 95% CI, 0.62-0.74), was the Cough, Overweight/obesity, Globus, Hiatal Hernia, Regurgitation, and male seX (COuGH RefluX) score, with a lower threshold of 2.5 and an upper threshold of 5.0 to predict proven GERD. In the validation phase, the COuGH RefluX score had an area under the curve of 0.67 (95% CI, 0.62-0.71), with 79% sensitivity and 81% specificity for proven GERD. CONCLUSIONS: The externally validated COuGH RefluX score is a clinically practical model to predict the likelihood of proven GERD. The score classifies most patients with chronic laryngeal symptoms as low/high likelihood of proven GERD, with only 38% remaining as indeterminate. Thus, the COuGH RefluX score can guide diagnostic strategies and reduce inappropriate proton pump inhibitor use or testing for patients referred for evaluation of chronic laryngeal symptoms.

Diagnostic Yield of Ambulatory Reflux Monitoring Systems for Evaluation of Chronic Laryngeal Symptoms.

INTRODUCTION: Among patients with chronic laryngeal symptoms, ambulatory reflux monitoring off acid suppression is recommended to evaluate for laryngopharyngeal reflux (LPR). However, reflux monitoring systems are diverse in configuration and monitoring capabilities, which present a challenge in creating a diagnostic reference standard in these patients. This study aimed to compare diagnostic yield and performance between reflux monitoring systems in patients with chronic laryngeal symptoms. METHODS: This multicenter, international study of adult patients referred for evaluation of LPR over a 5-year period (March 2018-May 2023) assessed and compared diagnostic yield of pathologic gastroesophageal reflux (GER+) on ambulatory reflux monitoring off acid suppression. RESULTS: Of 813 patients, 296 (36%) underwent prolonged wireless pH, 532 (65%) underwent 24-hour pH-impedance monitoring, and 15 (2%) underwent both tests. Overall diagnostic yield for GER+ was 36% and greater for prolonged wireless pH compared with that for 24-hour pH-impedance monitoring (50% vs 27%; P < 0.01). Among 15 patients who underwent both prolonged wireless pH and 24-h pH-impedance monitoring, concordance between systems for GER+ was 40%. The most common source of discordance was strong evidence of GER+ across multiple days on prolonged wireless pH compared with no evidence of GER+ on pH-impedance. DISCUSSION: In this multicenter international study of patients with chronic laryngeal symptoms referred for LPR evaluation, diagnostic yield of ambulatory reflux monitoring off acid suppression was 36% and rose to 50% when using wireless pH monitoring. In patients referred for chronic laryngeal symptoms, 24-hour pH-impedance monitoring may risk a low negative predictive value in patients with unproven GER+ disease.

Esophageal Hypervigilance and Visceral Anxiety Contribute to Symptom Severity of Laryngopharyngeal Reflux.

INTRODUCTION: Laryngopharyngeal reflux (LPR) is a clinical conundrum without a diagnostic gold standard. The Esophageal Hypervigilance and Anxiety Scale (EHAS) is a questionnaire designed for cognitive-affective evaluation of visceral sensitivity. We hypothesized that esophageal hypervigilance and symptom-specific anxiety have an etiopathological role in generation of LPR symptoms, especially when gastroesophageal reflux disease (GERD) cannot explain these symptoms. METHODS: Consecutive patients with LPR and/or GERD symptoms lasting >3 months were prospectively enrolled and characterized using the Reflux Symptom Index, GERD questionnaire, and EHAS. Eligible patients with negative endoscopy underwent 24-hour impedance-pH monitoring off acid suppression for phenotyping GERD and assessment of reflux burden, using conventional metrics (acid exposure time and number of reflux episodes) and novel metrics (mean nocturnal baseline impedance and postreflux swallow-induced peristaltic wave index). RESULTS: Of 269 enrolled patients (mean age 47.1 years, 21-65 years, 60.6% female), 90 patients were with concomitant GERD and LPR symptoms, 32 patients were with dominant LPR symptoms, 102 patients were with dominant GERD symptoms, and 45 were controls. Patients with concomitant GERD and LPR symptoms had higher EHAS than those with dominant GERD symptoms and controls ( P ≤ 0.001); patients with dominant LPR symptoms had higher EHAS than controls ( P = 0.007). On Pearson correlation, EHAS positively correlated with the Reflux Symptom Index. DISCUSSION: Esophageal hypervigilance and symptom-specific anxiety may be more important than reflux burden in LPR symptom perception.

Esophageal acid burden in reflux patients with normal endoscopy: Does esophageal peristalsis matter?

BACKGROUND: A majority of patients with gastroesophageal reflux disease (GERD) have normal endoscopy. We aimed to investigate whether esophageal primary and secondary peristalsis influence esophageal reflux parameters in patients with normal endoscopy. METHODS: We enrolled consecutive patients with typical reflux symptoms and normal endoscopy. All patients underwent High resolution manometry (HRM) and 24-h impedance-pH studies off therapy. During HRM, secondary peristalsis was evaluated using ten 20-mL rapid air infusions into the esophagus, while primary peristalsis was evaluated using ten 5-mL water swallows. RESULTS: A total of 43 patients completed the study; 13 patients had normal motility, 20 had ineffective esophageal motility (IEM), and 10 had absent contractility. Acid exposure time (AET) (total, supine, and upright) was significantly higher in those with absent primary peristalsis (absent contractility) compared to normal motility (P = 0.001; 0.01; 0.007) and IEM (P = 0.002; 0.02; 0.03). Supine AET was significantly higher in patients without secondary peristalsis compared to those with secondary peristalsis (P = 0.04). CONCLUSION: In the setting of normal endoscopy, acid reflux burden is more profound in patients with absent primary peristalsis, as well as in patients lacking a secondary peristaltic response to esophageal air distension.

Effects of phosphodiesterase-5 inhibitor sildenafil on esophageal secondary peristalsis: Studies with high-resolution manometry.

BACKGROUND AND AIM: Secondary peristalsis contributes to the clearance of retained refluxate from the esophagus. Sildenafil, a phosphodiesterase-5 inhibitor, inhibits primary esophageal peristalsis, but its effects on secondary peristalsis remain unknown. This study sought to investigate whether sildenafil could influence physiological characteristics of secondary peristalsis by applying high-resolution manometry (HRM). METHODS: Seventeen healthy volunteers (15 men and 2 women, aged 30.2 ± 6.4 years) underwent two HRM studies on separate days following the administration of either a placebo or 50 mg of sildenafil in a random order. Both studies were performed using a water-perfused HRM catheter containing one air injection channel positioned in the mid-esophagus. Secondary peristalsis was stimulated by a rapid mid-esophageal injection of 10 or 20 mL of air 1 h after the administration of either the placebo or sildenafil. The frequency and distal contractile integral of secondary peristalsis were then compared. RESULTS: Complete secondary peristalsis triggered by the 20-mL air injection was more frequent than observed with the 10-mL air injection (P < 0.001). The vigor of secondary peristalsis triggered by the injection of either volume of air was lower than that of primary peristalsis (P < 0.001). Sildenafil significantly reduced the success rate (P ≤ 0.001) and vigor (P < 0.001) of secondary peristalsis relative to the effects of the placebo at both distension volumes. CONCLUSIONS: Secondary peristalsis can be successfully triggered by rapid air injection during HRM. Sildenafil reduces both the success rate and the vigor of secondary peristalsis, similar to that seen with primary peristalsis.

Effects of codeine on esophageal peristalsis in humans using high resolution manometry.

BACKGROUND AND AIM: Opioid receptors agonists have been demonstrated to impair lower esophageal sphincter (LES) relaxation and induce spastic esophageal dysmotility, but little was known for their impact on distension-induced secondary peristalsis. The aim of the study was to investigate the hypothesis whether acute administration of codeine can influence physiological characteristics of primary and secondary peristalsis in healthy adults. METHODS: Eighteen healthy volunteers (13 men, mean age 27.5 years, aged 20-43 years) underwent high resolution manometry (HRM) with a catheter containing an injection port in mid-esophagus. Secondary peristalsis was performed with 10 and 20 mL rapid air injections. Two different sessions including acute administration of codeine (60 mg) or the placebo were randomly performed. RESULTS: Codeine significantly increased 4-s integrated relaxation pressure (IRP-4s) (P = 0.003) and shortened distal latency (DL) (P = 0.003) of primary peristalsis. The IRP-4s of secondary peristalsis was also significantly higher after codeine than the placebo during air injections with 10 mL (P = 0.048) and 20 mL (P = 0.047). Codeine significantly increased the frequency of secondary peristalsis during air injections with 10 mL than the placebo (P = 0.007), but not for air injection with 20 mL (P = 0.305). CONCLUSIONS: In addition to impair LES relaxation and reduce distal latency of primary peristalsis, codeine impairs LES relaxation of secondary peristalsis and increases secondary peristaltic frequency. Our study supports the notion in human esophagus that the impact of opioids on peristaltic physiology appears to be present in both primary and secondary peristalsis.

Effect of prucalopride on sildenafil-induced inhibition of esophageal peristalsis in healthy adults.

BACKGROUND AND AIM: Prucalopride, a high-affinity 5-hydroxytryptamine 4 receptor agonist, promotes esophageal peristalsis, while phosphodiesterase type 5 inhibitor sildenafil inhibits esophageal peristalsis. The present study was aimed to evaluate whether prucalopride would augment esophageal peristalsis subsequent to the application of sildenafil. METHODS: Seventeen healthy adults underwent high-resolution manometry by a catheter with one injection port located in the mid-esophagus. Secondary peristalsis was assessed by rapid air injections after water swallows. Two sessions were randomly performed including acute administration of sildenafil 50 mg after pretreatment with prucalopride or the placebo. RESULTS: The frequency of primary peristalsis subsequent to the administration of sildenafil was significantly increased by prucalopride (P = 0.02). Prucalopride also significantly increased distal contractile integral of primary peristalsis subsequent to the administration of sildenafil (P = 0.03). No difference in the frequency of secondary peristalsis subsequent to the administration of sildenafil for air injects of 10 mL (P = 0.14) or 20 mL (P = 0.21) was found between prucalopride and placebo. Prucalopride did not change distal contractile integral of secondary peristalsis subsequent to the administration of sildenafil for air injections of 10 mL (P = 0.09) or 20 mL (P = 0.12). CONCLUSIONS: Prucalopride modulates sildenafil-induced inhibition of primary peristalsis by increasing its effectiveness and peristaltic wave amplitude. Our findings suggest that activation of 5-hydroxytryptamine 4 receptors plays a role in mediating sildenafil-induced inhibition of esophageal primary peristalsis rather than secondary peristalsis.

Similarities and differences between IBS-C and FC with regards to symptomatology, sleep quality and psychological attributes.

BACKGROUND: Irritable bowel syndrome (IBS) and functional constipation (FC) are highly prevalent in the general population and have significant symptom overlap, while the clinical associations and psychological links between IBS and FC remains poorly understood. We aimed to compare the clinical, metabolic and psychological factors between patients with FC patients and constipation predominated IBS. METHODS: We consecutively enrolled 360 patients from the outpatient clinics of Hualien Tzu Chi medical center. Constipation-predominant IBS (IBS-C) and FC were diagnosed based on Rome III criteria. All participants completed the Pittsburg Sleep Quality Index (PSQI) score, the State Trait Anxiety Inventory (STAI) score and the Taiwanese Depression Questionnaire (TDQ) score. RESULTS: Fifty-four patients had FC and twenty-three patients had IBS-C. Compared to asymptomatic controls, FC/IBS-C groups had female predominance (p < 0.001), FC as well as more GI discomforts and inferior psychosocial characteristics (p < 0.05). Compared to FC, IBS-C had higher severity scores of abdominal distention (4.52 ± 1.90 vs. 3.07 ± 1.88) and heartburn (2.17 ± 1.50 vs. 1.46 ± 1.14). However, FC was independently associated with poor sleep quality [adjusted OR: 1.19 (1.08-1.31), p < 0.001] and IBS-C with depression [adjusted OR: 1.07 (1.02-1.12), p = 0.005]. CONCLUSION: Patients with FC and IBS-C shared many similar GI complaints and psychosocial characteristics, however IBS-C had more severe bloating, heartburn and depression and FC had worse sleeping quality.

Evaluation of Baseline Impedance During Water-perfused High Resolution Impedance Manometry in Patients With Symptomatic GERD.

GOALS: We aimed to investigate the hypothesis whether baseline impedance measured during water-perfused high resolution impedance manometry (HRIM) can help discriminate patients with reflux symptoms from the controls and predict the response to the proton pump inhibitors (PPIs). BACKGROUND/AIM: Baseline impedance measured during solid-state HRIM can reliably discriminate patients with gastroesophageal reflux disease (GERD) from controls. STUDY: We enrolled consecutive patients with typical reflux symptoms and healthy controls for the measurement of baseline impedance during the landmark period of HRIM. All patients were given PPIs and PPI response was assessed after 8 weeks of the treatment. RESULTS: Baseline mucosa impedance measured during HRIM was lower in GERD patients than the controls (1861±183 vs. 3371±250 Ω; P<0.001). Baseline impedance during water-perfused HRIM had moderate diagnostic accuracy for differentiating symptomatic GERD with an area under the curve of 0.853 on receiver operating characteristics analysis. A threshold of 2530 Ω for baseline impedance had a sensitivity of 88.3% and specificity of 82.4% for GERD with a positive predictive value of 83.4% and negative predictive value of 87.6%. Among symptomatic GERD patients, poor PPI responders had higher baseline impedance than those without it (2340±260 vs. 1479±189 Ω; P=0.02). BMI negatively correlated to base impedance in either controls (r=-0.59; P=0.012) or GERD patients (r=-0.47; P=0.047). CONCLUSIONS: Baseline impedance measurement during water-perfused HRIM helps differentiate patients with typical reflux symptoms from controls and also serves as a potential utility in predicting PPI response.

Gamma-aminobutyric acid receptor type B agonist baclofen inhibits acid-induced excitation of secondary peristalsis but not heartburn sensation.

BACKGROUND AND AIM: Acute esophageal acid infusion promotes distension-induced secondary peristalsis. The gamma-aminobutyric acid receptor type B (GABA-B) receptors activation inhibits secondary peristalsis. This study aimed to test the hypothesis whether acid excitation of secondary peristalsis can be influenced by baclofen. METHODS: Secondary peristalsis was performed with intra-esophageal slow and rapid air injections in 13 healthy subjects. Direct esophageal infusion of 0.1 N HCl following pretreatment with placebo or baclofen was randomly performed at least 1 week apart. Symptom intensity, distension thresholds, and peristaltic parameters were determined and compared between each study protocol. RESULTS: The intensity of heartburn symptom in response to esophageal acid infusion was significantly greater with baclofen than the placebo (P = 0.002). The threshold volume of secondary peristalsis during slow air injections in response to acid infusion was significantly greater with baclofen than the placebo (P = 0.001). Baclofen significantly increased the threshold volume of secondary peristalsis during rapid air injections in response to acid infusion (P = 0.001). The frequency of secondary peristalsis in response to acid infusion was significantly decreased by baclofen as compared with the placebo (P = 0.001). Baclofen significantly decreased peristaltic amplitudes in response to acid infusion during rapid air injections (P = 0.007). CONCLUSIONS: Gamma-aminobutyric acid receptor type B agonist baclofen inhibits acid excitation of secondary peristalsis in human esophagus, which is probably mediated by both muscular and mucosal mechanoreceptors. This work supports the evidence of potential involvement of GABA-B receptors in negative modulation of acid excitation of esophageal perception as well as secondary peristalsis.

Clinical and psychological characteristics in gastroesophageal reflux disease patients overlapping with laryngopharyngeal reflux symptoms.

BACKGROUND AND AIM: Laryngopharyngeal reflux (LPR) defined as reflux of gastric content reaching above the upper esophageal sphincter is frequently found in patients with gastroesophageal reflux disease (GERD). This study aimed to investigate clinical and psychological differences between GERD patients with or without LPR symptoms. METHODS: This study enrolled 303 consecutive patients with proton pump inhibitor treatment-naïve scheduled for upper endoscopy because of troublesome reflux symptoms and recognized as GERD by non-dyspepsia reflux disease questionnaire score. Included GERD patients were further categorized into two study groups: with or without LPR by reflux symptoms index score. All participants were also evaluated with questionnaires for depression, anxiety, and sleep disturbances. RESULTS: There were 132 (43.6%) GERD patients with LPR symptoms and 171 (56.4%) GERD patients without LPR symptoms. GERD patients with LPR symptoms had more depression (P < 0.001), sleep disturbance (P = 0.002), irritable bowel syndrome (P = 0.008), functional dyspepsia (P = 0.005), and reflux symptoms burden (P < 0.001) than those without LPR symptoms. Erosive esophagitis was more in patients without LPR symptoms (P = 0.03). GERD patients with LPR symptoms (28.8%) had more complex psychological distress than those without LPR symptoms (28.8% vs 14%, P < 0.001). Reflux symptoms burden, sleep disturbance, and erosive esophagitis were independently associated with GERD overlapping with LPR symptoms. CONCLUSIONS: Gastroesophageal reflux disease patients with LPR symptoms appear to have more reflux symptoms, psychological distress, and functional gastrointestinal disturbance but less erosive esophagitis. This work suggests that therapeutic strategy with tailored multidimensional approach is promising for GERD patients overlapping with LPR symptoms.

Sleep Disturbance and Its Association with Gastrointestinal Symptoms/Diseases and Psychological Comorbidity.

BACKGROUND/AIMS: We aimed to investigate gastrointestinal symptoms, clinical characteristics, and psychological factors in subjects with and without sleep disturbance (SD) in a health screening cohort. METHODS: We enrolled 2,752 consecutive subjects during their health checkups. All participants underwent an evaluation with questionnaires. Demographic characteristics and biochemical data were recorded. SD was confirmed when Pittsburgh Sleep Quality Index score was greater than 5. RESULTS: Among the study population (n = 2,674), 956 (36%) individuals had SD. SD was associated with female gender, older age, lower level of education, higher systolic blood pressure, higher serum high-density lipoprotein levels and higher prevalence of functional dyspepsia and irritable bowel syndrome (IBS). SD subjects also had more depression, more anxiety, more severe gastrointestinal reflux disease symptoms and higher prevalence of non-erosive reflux disease (NERD; p < 0.001). SD was -independently associated with female gender (OR 1.75, p < 0.001), older age (OR 1.03, p < 0.001), NERD (OR 1.88, p = 0.004), IBS (OR 1.51, p = 0.043), and depression (OR 1.16, p < 0.001) by multivariate analysis. CONCLUSIONS: Future studies will be needed to clarify the interrelationships among SD, psychological stress, and functional gastrointestinal disorders.

Assessment of esophageal function using provocative tests during high resolution manometry: A single-center experience.

BACKGROUND: Provocative tests were used to provide additional information during performing high resolution manometry (HRM). The study aimed to evaluate whether it is feasible to test esophageal function with different esophageal provocative tests during HRM. METHODS: 23 healthy volunteers (9 women; mean age 25 years, range 21-30 years) underwent water-perfused HRM. Each subject received 10 liquid swallows, 10 solid swallows, 10 liquid swallows with abdominal compression, and 5 multiple rapid swallowing (MRS). RESULTS: DCI was significantly greater during abdominal compression than that of solid swallows (p = 0.025). Compared with liquid swallows, there was a significant decrease in CFV during solid swallows (p = 0.04). DL was significantly greater during solid swallows than that of liquid swallows (p < 0.001) or abdominal compression (p < 0.001). IRP 4s was significantly lower during abdominal compression than that of liquids (p < 0.001) or solid swallows (p = 0.006). All subjects had complete inhibition during MRS and increased DCI after MRS as compared with liquid swallows (p < 0.05). CONCLUSION: Esophageal provocative test may provide additional utility in performing HRM studies. The data for esophageal provocative tests are distinct from standard liquid swallows.

Impact of concomitant dyspepsia and irritable bowel syndrome on symptom burden in patients with gastroesophageal reflux disease.

BACKGROUND: Patients with gastroesophageal reflux disease (GERD) frequently report symptoms like dyspepsia or/and irritable bowel syndrome (IBS). The aim of the study was to investigate the impact of symptom overlap on GERD symptom burden. We also investigate whether GERD overlapping dyspepsia or/and IBS would have different clinical and psychological features as compared with GERD alone. METHODS: A total of 2752 subjects were screened from a health check-up population. We compared the clinical and psychological factors among subjects with GERD alone and with overlap of two or all three diseases. All participants underwent an evaluation with questionnaires including Reflux Disease Questionnaire score, Pittsburgh Sleep Quality Index, Taiwanese Depression Questionnaire, and State-Trait Anxiety Inventory before receiving endoscopic exam. RESULTS: Among the GERD population, we identified 26 with IBS (GERD-IBS), 60 with dyspepsia (GERD-D), and 25 subjects with overlap of all three conditions (GERD-D-IBS). GERD-D and GERD-D-IBS subjects had more severe GERD symptoms as compared subjects with GERD alone (p < 0.001). Subjects with overlapping dyspepsia or/and IBS showed a significant increase in the severity of depression and poorer sleep quality than subjects with GERD alone. Notably, anxiety scores did not differ significantly between subjects with overlapping diseases and GERD alone. CONCLUSION: Our study demonstrates that disease overlap in GERD population is associated with greater symptom burden, higher depression and poorer sleep quality, but not with anxiety. This study highlights the importance of identifying overlapping conditions as a therapeutic strategy for better management of GERD.

Esophageal motor abnormalities in gastroesophageal reflux disorders.

Gastroesophageal reflux disease (GERD), a prevalent condition with multifactorial pathogenesis, involves esophageal motor dysmotility as a key contributing factor to its development. When suspected GERD patients have an inadequate response to proton-pump inhibitor (PPI) therapy and normal upper endoscopy results, high-resolution manometry (HRM) is utilized to rule out alternative diagnosis such as achalasia spectrum disorders, rumination, or supragastric belching. At present, HRM continues to provide supportive evidence for diagnosing GERD and determining the appropriate treatment. This review focuses on the existing understanding of the connection between esophageal motor findings and the pathogenesis of GERD, along with the significance of esophageal HRM in managing GERD patients. The International GERD Consensus Working Group introduced a three-step method, assessing the esophagogastric junction (EGJ), esophageal body motility, and contraction reserve with multiple rapid swallow (MRS) maneuvers. Crucial HRM abnormalities in GERD include frequent transient lower esophageal sphincter relaxations, disrupted EGJ, and esophageal body hypomotility. Emerging HRM metrics like EGJ-contractile integral and innovative provocative maneuver like straight leg raise have the potential to enhance our understanding of factors contributing to GERD, thereby increasing the value of HRM performed in patients who experience symptoms suspected of GERD.

Effects of Codeine on Esophageal Peristalsis in Patients With Ineffective Esophageal Motility: Studies Using High-resolution Manometry.

Background/Aims: This study aims to evaluate the effects of acute codeine administration on primary and secondary esophageal peristalsis in patients with ineffective esophageal motility (IEM). Methods: Eighteen IEM patients (8 women; mean age 37.8 years, range 23-64 years) were enrolled in the study. The patients underwent high-resolution manometry exams, consisting of 10 single wet swallows, multiple rapid swallows, and ten 20 mL rapid air injections to trigger secondary peristalsis. All participants completed 2 separate sessions, including acute administration of codeine (60 mg) and placebo, in a randomized order. Results: Codeine significantly increased the distal contractile integral (566 ± 81 mmHg∙s∙cm vs 247 ± 36 mmHg∙s∙cm, P = 0.001) and shortened distal latency (5.7 ± 0.2 seconds vs 6.5 ± 0.1 seconds, P < 0.001) for primary peristalsis compared with these parameters after placebo treatment. The mean total break length decreased significantly after codeine treatment compared with the length after placebo (P = 0.003). Codeine significantly increased esophagogastric junction-contractile integral (P = 0.028) but did not change the 4-second integrated relaxation pressure (P = 0.794). Codeine significantly decreased the frequency of weak (P = 0.039) and failed contractions (P = 0.009), resulting in increased frequency of normal primary peristalsis (P < 0.136). No significant differences in the ratio of impaired multiple rapid swallows inhibition and parameters of secondary peristalsis were detected. Conclusions: In IEM patients, acute administration of codeine increases contraction vigor and reduces distal latency of primary esophageal peristalsis, but has no effect on secondary peristalsis. Future studies are required to further elucidate clinical relevance of these findings, especially in the setting of gastroesophageal reflux disease with IEM.

Impact of Esophageal Motility on Microbiome Alterations in Symptomatic Gastroesophageal Reflux Disease Patients With Negative Endoscopy: Exploring the Role of Ineffective Esophageal Motility and Contraction Reserve.

Background/Aims: Ineffective esophageal motility (IEM) is common in patients with gastroesophageal reflux disease (GERD) and can be associated with poor esophageal contraction reserve on multiple rapid swallows. Alterations in the esophageal microbiome have been reported in GERD, but the relationship to presence or absence of contraction reserve in IEM patients has not been evaluated. We aim to investigate whether contraction reserve influences esophageal microbiome alterations in patients with GERD and IEM. Methods: We prospectively enrolled GERD patients with normal endoscopy and evaluated esophageal motility and contraction reserve with multiple rapid swallows during high-resolution manometry. The esophageal mucosa was biopsied for DNA extraction and 16S ribosomal RNA gene V3-V4 (Illumina)/full-length (Pacbio) amplicon sequencing analysis. Results: Among the 56 recruited patients, 20 had normal motility (NM), 19 had IEM with contraction reserve (IEM-R), and 17 had IEM without contraction reserve (IEM-NR). Esophageal microbiome analysis showed a significant decrease in microbial richness in patients with IEM-NR when compared to NM. The beta diversity revealed different microbiome profiles between patients with NM or IEM-R and IEM-NR (P = 0.037). Several esophageal bacterial taxa were characteristic in patients with IEM-NR, including reduced Prevotella spp. and Veillonella dispar, and enriched Fusobacterium nucleatum. In a microbiome-based random forest model for predicting IEM-NR, an area under the receiver operating characteristic curve of 0.81 was yielded. Conclusions: In symptomatic GERD patients with normal endoscopic findings, the esophageal microbiome differs based on contraction reserve among IEM. Absent contraction reserve appears to alter the physiology and microbiota of the esophagus.

Artificial intelligence facilitates measuring reflux episodes and postreflux swallow-induced peristaltic wave index from impedance-pH studies in patients with reflux disease.

BACKGROUND/AIM: Reflux episodes and postreflux swallow-induced peristaltic wave (PSPW) index are useful impedance parameters that can augment the diagnosis of gastroesophageal reflux disease (GERD). However, manual analysis of pH-impedance tracings is time consuming, resulting in limited use of these novel impedance metrics. This study aims to evaluate whether a supervised learning artificial intelligence (AI) model is useful to identify reflux episodes and PSPW index. METHODS: Consecutive patients underwent 24-h impedance-pH monitoring were enrolled for analysis. Multiple AI and machine learning with a deep residual net model for image recognition were explored based on manual interpretation of reflux episodes and PSPW according to criteria from the Wingate Consensus. Intraclass correlation coefficients (ICCs) were used to measure the strength of inter-rater agreement of data between manual and AI interpretations. RESULTS: We analyzed 106 eligible patients with 7939 impedance events, of whom 38 patients with pathological acid exposure time (AET) and 68 patients with physiological AET. On the manual interpretation, patients with pathological AET had more reflux episodes and lower PSPW index than those with physiological AET. Overall accuracy of AI identification for reflux episodes and PSPW achieved 87% and 82%, respectively. Inter-rater agreements between AI and manual interpretations achieved excellent for individual numbers of reflux episodes and PSPW index (ICC = 0.965 and ICC = 0.921). CONCLUSIONS: AI has the potential to accurately and efficiently measure impedance metrics including reflux episodes and PSPW index. AI can be a reliable adjunct for measuring novel impedance metrics for GERD in the near future.

Effects of the GABA(B) agonist baclofen on volitional swallowing in normal subjects.

The GABA(B) receptor agonist baclofen is known to suppress the rate of spontaneous swallowing but not pharyngeal muscle contraction. The extent to which baclofen may alter volitional swallowing is not currently known. We investigated the effects of baclofen in healthy subjects, hypothesizing that baclofen exposure would alter volume-regulation and/or piecemeal deglutition behaviors during volitional swallowing attempts. Pharyngeal high-resolution manometry impedance (P-HRM-I) protocol was used to assess swallowing function of 22 healthy adult volunteers (median 29 years) who were investigated on two occasions, receiving 40 mg baclofen (oral) 1 h before study, or placebo (randomized). Standard swallow function variables recommended by the pharyngeal HRM Working Group were derived for 5 ml, 10 ml, and 20 ml volumes of thin and extremely thick liquid challenges. Multiple swallow behaviors, comprising two swallows <5 s apart, were characterized. The spontaneous swallow rate was also determined. Baclofen exposure had no overall significant effect on swallow variables. Upper esophageal sphincter pressure was weaker during exposure to baclofen, during both the pre-deglutitive and post-deglutitive phases of the swallow (p < 0.05 during thick liquid swallows). Piecemeal swallows, where the bolus is separated in two potions, were significantly more common during 20 ml boluses (p = 0.002). Baclofen decreased the frequency of piecemeal deglutition overall. Baclofen has limited to no effect on volitional swallowing measures, however, does reduce the likelihood of initiation of piecemeal deglutition to large volume challenges.