Increase of weakly acidic gas esophagopharyngeal reflux (EPR) and swallowing-induced acidic/weakly acidic EPR in patients with chronic cough responding to proton pump inhibitors

2020 Seoul Consensus on the Diagnosis and Management of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis.

Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

ESNM/ANMS consensus paper: Diagnosis and management of refractory gastro-esophageal reflux disease

Up to 40% of patients with symptoms suspicious of gastroesophageal reflux disease (GERD) do not respond completely to proton pump inhibitor (PPI) therapy. The term "refractory GERD" has been used loosely in the literature. A distinction should be made between refractory symptoms (ie, symptoms may or may not be GERD-related), refractory GERD symptoms (ie, persisting symptoms in patients with proven GERD, regardless of relationship to ongoing reflux), and refractory GERD (ie, objective evidence of GERD despite adequate medical management). The present ESNM/ANMS consensus paper proposes use the term "refractory GERD symptoms" only in patients with persisting symptoms and previously proven GERD by either endoscopy or esophageal pH monitoring. Even in this context, symptoms may or may not be reflux related. Objective evaluation, including endoscopy and esophageal physiologic testing, is requisite to provide insights into mechanisms of symptom generation and evidence of true refractory GERD. Some patients may have true ongoing refractory acid or weakly acidic reflux despite PPIs, while others have no evidence of ongoing reflux, and yet others have functional esophageal disorders (overlapping with proven GERD confirmed off therapy). In this context, attention should also be paid to supragastric belching and rumination syndrome, which may be important contributors to refractory symptoms.

Normal acid exposure time in esophageal pH monitoring in Asian and Western populations: A systematic review and meta-analysis

BACKGROUND

Esophageal acid exposure time (AET) during 24 h pH monitoring is reproducible and predictive outcomes of treatment for gastroesophageal reflux disease. Several small Asian studies have investigated the normal range of the AET; the range may be different from that in Western populations. We evaluated its normal range in healthy Asian compared to Western subjects.

METHODS

We searched PubMed, Embase, Cochrane Library, and KoreaMed for studies that reported pH monitoring parameters in healthy subjects. Studies that reported the AET values of healthy subjects were eligible for the analyses. The upper limit of normal of the AET was obtained from the 95th percentile of the available raw data or calculated as the mean value +2 standard deviations.

KEY RESULTS

Nineteen Asian and 49 Western studies were assessed. The estimated AET values were analyzed using a bootstrapping technique, weighted according to the sample size. The mean AET was 1.1% and 2.9% in the Asian and Western populations, respectively. The upper limit of the reference range was 3.2% (95% confidence interval [CI], 2.7-3.9%) and 8.2 (95% CI, 6.7-9.9) in the Asian and Western populations, respectively. The normal AET differed between the Asian and Western populations because the CI of the two groups did not overlap.

CONCLUSIONS & INFERENCES

The upper limit of normal of the AET in healthy Asian subjects was 3.2% (95% CI, 2.7-3.9%), which was lower than that of healthy Western subjects.

ACG Clinical Guidelines: Clinical Use of Esophageal Physiologic Testing

Esophageal symptoms are common and may indicate the presence of gastroesophageal reflux disease (GERD), structural processes, motor dysfunction, behavioral conditions, or functional disorders. Esophageal physiologic tests are often performed when initial endoscopic evaluation is unrevealing, especially when symptoms persist despite empiric management. Commonly used esophageal physiologic tests include esophageal manometry, ambulatory reflux monitoring, and barium esophagram. Functional lumen imaging probe (FLIP) has recently been approved for the evaluation of esophageal pressure and dimensions using volumetric distension of a catheter-mounted balloon and as an adjunctive test for the evaluation of symptoms suggestive of motor dysfunction. Targeted utilization of esophageal physiologic tests can lead to definitive diagnosis of esophageal disorders but can also help rule out organic disorders while making a diagnosis of functional esophageal disorders. Esophageal physiologic tests can evaluate obstructive symptoms (dysphagia and regurgitation), typical and atypical GERD symptoms, and behavioral symptoms (belching and rumination). Certain parameters from esophageal physiologic tests can help guide the management of GERD and predict outcomes. In this ACG clinical guideline, we used the Grading of Recommendations Assessment, Development and Evaluation process to describe performance characteristics and clinical value of esophageal physiologic tests and provide recommendations for their utilization in routine clinical practice.

Surgical Treatment of Extraesophageal Manifestations of Gastroesophageal Reflux Disease

OBJECTIVE

To review the current literature on the role of antireflux surgery (ARS) for the treatment of extraesophageal manifestations of GERD. The extraesophageal manifestations of gastroesophageal reflux disease (GERD) include chronic cough, laryngopharyngeal reflux, and asthma. They are responsible for significant morbidity in affected patients and a high economic burden on healthcare resources. We recently published a larger review on the symptoms, diagnosis, medical, and surgical treatment of the extraesophageal manifestations of GERD. Through our investigation, we found that the role of ARS for respiratory symptoms was unclear. Hence, we resorted through the data of our previous meta-analysis to compile a comprehensive and focused review on the role of ARS for respiratory symptoms.

METHODS

Using the archive of our previous meta-analysis, we selected studies extracted from the MEDLINE, Cochran, PubMed, Google Scholar, and Embase databases pertaining to the surgical treatment of extraesophageal manifestations of reflux (cough laryngopharyngeal reflux, and asthma). We applied a similar reporting methodology as was used in our previous manuscript and then hand searched the bibliographies of included studies yielding a total of 27 articles for review. We graded the level of evidence and classified recommendations by size of treatment effect per the American Heart Association Task Force on Practice Guidelines.

RESULTS

Observational data indicated that syndromes of chronic cough, laryngopharyngeal reflux and asthma might improve after antireflux surgery only in highly selected patients-likely those with non-acid reflux-while those patients with objective markers of asthma severity do not. Because of the varied methods of diagnosis and surgical technique, non-comparative observational data may be unreliable. Additionally, our search found no randomized controlled trials (RCTs) comparing antireflux surgery to medical therapy in the treatment of cough or laryngopharyngeal reflux. One RCT compared medical treatment to antireflux surgery in patients with asthma, but medical treatment included high-dose H₂ blockers instead of PPIs.

CONCLUSIONS

Extraesophageal manifestations of GERD are common, costly, and difficult to treat. ARS might be effective in highly selected patients, especially in those whose extraesophageal manifestations are caused by non-acid reflux. The available data to date are generally of poor quality or outdated. Well-designed randomized controlled trials or large-scale observational cohort studies are urgently needed.

Diagnosis and Treatment of the Extraesophageal Manifestations of Gastroesophageal Reflux Disease

OBJECTIVE

To review the clinical presentation, diagnosis, and treatment options available for management of extraesophageal manifestations of gastroesophageal reflux disease (GERD) and to compare the most recent technological advances to the existing guidelines.

SUMMARY BACKGROUND DATA

Extraesophageal manifestations of GERD include cough, laryngopharyngeal reflux (LPR), and asthma. Recent advances in diagnostic modalities may have outpaced the existing diagnostic and therapeutic clinical guidelines.

METHODS

We searched the MEDLINE, Cochrane, and Embase databases for articles pertaining to the presentation, diagnosis, and treatment of extraesophageal manifestations of reflux, specifically cough due to reflux, LPR, and asthma due to reflux. Search terms applied to 3 thematic topics: diagnosis, medical treatment, and surgical treatment. We had searched the bibliographies of included studies, yielding a total of 271 articles for full review. We graded the level of evidence and classified recommendations by size of treatment effect, according to the guidelines from the American Heart Association Task Force on Practice Guidelines.

RESULTS

One hundred twenty-eight articles met criteria for analysis. Our findings show that the diagnosis of cough, LPR, or asthma due to gastroesophageal reflux is difficult, as no criterion standard test exits. Also, patients often present without heartburn or regurgitation typical of GERD. Combined multichannel intraluminal impedance, the pH (MII-pH) monitoring system, and the symptom association probability (SAP) test might distinguish extraesophageal manifestations of reflux from idiopathic chronic cough, laryngitis due to other causes, and atopic asthma. In addition, extraesophageal manifestations of reflux are most effectively diagnosed with a stepwise approach incorporating empiric treatment and antisecretory therapy, combined MII-pH monitoring, and surgical intervention in few selected cases.

CONCLUSIONS

Recent studies demonstrate the potential diagnostic role of MII-pH monitoring. Surgical intervention provides resolution of extraesophageal symptoms less reliably than typical symptoms when the patient has GERD.

Liquid-containing Refluxes and Acid Refluxes May Be Less Frequent in the Japanese Population Than in Other Populations: Normal Values of 24- hour Esophageal Impedance and pH Monitoring

Background/Aims

Twenty-four-hour esophageal impedance and pH monitoring allows detection of all types of reflux episodes and is considered the best technique for identifying gastroesophageal refluxes. However, normative data for the Japanese population are lacking. This multicenter study aimed to establish the normal range of 24-hour esophageal impedance and pH data both in the distal and the proximal esophagus in Japanese subjects.

Methods

Forty-two healthy volunteers (25 men and 17 women) with a mean ± standard deviation age of 33.3 ± 12.4 years (range: 22–72 years) underwent a combined 24-hour esophageal impedance and pH monitoring. According to the physical and pH properties, distal or proximal esophageal reflux events were categorized.

Results

Median 45 reflux events occurred in 24 hours, and the 95th percentile was 85 events. Unlike previous reports, liquid-containing reflux events are median 25/24 hours with the 95th percentile of 62/24 hours. Acidic reflux events were median 11/24 hours with the 95th percentile of 39/24 hours. Non-acidic gas reflux events were median 15/24 hours with the 95th percentile of 39/24 hours. Proximal reflux events accounted for 80% of the total reflux events and were mainly non-acidic gas refluxes. About 19% of liquid and mixed refluxes reached the proximal esophagus.

Conclusions

Unlike previous studies, liquid-containing and acidic reflux events may be less frequent in the Japanese population. Non-acidic gas reflux events may be frequent and a cause of frequent proximal reflux events. This study provides important normative data for 24-hour impedance and pH monitoring in both the distal and the proximal esophagus in the Japanese population.

Respiratory disease and the oesophagus: reflux, reflexes and microaspiration

Gastro-oesophageal reflux is associated with a wide range of respiratory disorders, including asthma, isolated chronic cough, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and cystic fibrosis. Reflux can be substantial and reach the proximal margins of the oesophagus in some individuals with specific pulmonary diseases, suggesting that this association is more than a coincidence. Proximal oesophageal reflux in particular has led to concern that microaspiration might have an important, possibly even causal, role in respiratory disease. Interestingly, reflux is not always accompanied by typical reflux symptoms, such as heartburn and/or regurgitation, leading many clinicians to empirically treat for possible gastro-oesophageal reflux. Indeed, costs associated with use of acid suppressants in pulmonary disease far outweigh those in typical GERD, despite little evidence of therapeutic benefit in clinical trials. This Review comprehensively examines the possible mechanisms that might link pulmonary disease and oesophageal reflux, highlighting the gaps in current knowledge and limitations of previous research, and helping to shed light on the frequent failure of antireflux treatments in pulmonary disease.

Laryngopharyngeal Reflux in Children with Chronic Otitis Media with Effusion

BACKGROUND/AIMS

To evaluate the characteristic properties of laryngopharyngeal reflux (LPR) and gastroesophageal reflux (GER) in children with otitis media with effusion (OME) using 24-hour multichannel intraluminal impedance combined with dual-probe (pharyngeal and esophageal) pH-metry.

METHODS

Children aged 7-10 years of age with OME underwent 24-hour multichannel intraluminal impedance pH-metry. The upper pH sensor was situated 1 cm above the upper esophageal sphincter, and the lower pH sensor was placed 3-5 cm above the lower esophageal sphincter. Parents were asked to complete the gastroesophageal reflux assessment of symptoms in a pediatrics questionnaire.

RESULTS

Twenty-eight children were enrolled; LPR was detected in 19 (67.9%) children. The criteria of the LPR diagnosis was the presence of at least one supraesophageal episode with a pH < 5.0 and a change in the pH value measured from the initial level at the upper sensor of > 0.2. In total, 64 episodes were observed. Assessment of all LPR episodes showed the presence of 246 episodes in the entire study. A considerable predominance of weakly acidic episodes (87.8%) was noted; there were 6.5% acidic episodes, and weakly alkaline episodes reached 5.7%. Pathological GER was noted in 10 (35.7%) subjects. Acid GER was detected in 8 children, 2 of whom demonstrated non-acidic reflux. In the LPR-negative patients, no pathological GER was confirmed with the exception of a single case of non-acidic reflux.

CONCLUSIONS

LPR was frequently noted in the group of children with OME, and it might be an important risk factor in this common disease.

Evaluation of proton pump inhibitor-resistant nonerosive reflux disease by esophageal manometry and 24-hour esophageal impedance and pH monitoring

BACKGROUND

Patients with proton pump inhibitor (PPI)-resistant nonerosive reflux disease (NERD) include subgroups that have markedly different pathophysiology. This study aimed to clarify the pathophysiology of NERD by esophageal manometry with 24-hour esophageal impedance and pH monitoring.

METHODS

Eighteen consecutive outpatients referred to our expert center for functional gastrointestinal motility with suspected PPI-resistant NERD were enrolled. Manometry was performed to detect esophageal motility disorders. Subsequently, 24-hour esophageal impedance and pH monitoring was done while patients were on PPI therapy.

RESULTS

Manometry revealed 1 case of achalasia, 1 case of nutcracker esophagus and 3 cases of diffuse esophageal spasm. Three patients had ineffective esophageal motility, with impedance and pH monitoring being performed in 2 of them. Esophageal acid exposure (%time pH <4) was normal in both, but the symptom index (SI) was positive for nonacidic reflux in 1 patient. One of the 10 patients with normal esophageal motility had abnormal esophageal acid exposure. The SI was positive for weakly acidic and nonacidic reflux in 3 of the remaining 9 patients with normal esophageal acid exposure. Five of the other 6 patients seemed to have functional heartburn.

CONCLUSION

A substantial percentage (28%) of patients with suspected PPI-resistant NERD had primary esophageal motility disorders. Both nonacidic reflux and weakly acidic reflux are important contributors to the symptoms of patients with PPI-resistant NERD. Esophageal manometry is required to exclude motility disorders, while 24-hour esophageal impedance and pH monitoring is invaluable for assessing symptom-reflux associations and the indications for fundoplication in patients with suspected PPI-resistant NERD.

Current perspectives on reflux laryngitis

Laryngopharyngeal reflux (LPR) is an extraesophageal manifestation of gastroesophageal reflux disease (GERD). With the increase of GERD patients, the importance of LPR is acknowledged widely. However, the pathophysiology of LPR is not understood completely and the diagnostic criteria for LPR remain controversial. Unfortunately, a gold standard diagnostic test for reflux laryngitis is not available. Recently, an experimental animal model for reflux laryngitis was developed to investigate the pathophysiology of reflux laryngitis. An empirical trial of lifestyle modification and proton pump inhibitor therapy is a reasonable approach for LPR symptoms. Alternatives after failure with aggressive medical treatment are limited and multichannel intraluminal impedance and pH monitoring is currently the best alternative to detect nonacid reflux. Additional prospective and evidence-based research is anticipated.

Chronic cough: a gastroenterology perspective

PURPOSE OF REVIEW

The purpose of this review is to highlight recent work and provide recommendations on the approach for diagnosis and management of chronic cough in a gastroenterology clinic.

RECENT FINDINGS

Chronic cough is a burdensome symptom affecting a large number of patients and contributes significant cost to the healthcare system. Recent work has shown that select patients may benefit from acid-suppressive therapy and even surgery when there is true pathologic evidence of reflux disease with cough. However, judicious use and proper interpretation of diagnostic testing for gastroesophageal reflux in the setting of cough is important to avoid unnecessary or inappropriate therapy.

SUMMARY

Chronic cough remains a vexing problem for many physicians, including gastroenterologists. It is important that physicians approach refractory cough in a multidisciplinary manner. Future research is needed to better understand the likely central hypersensitivity response mediating reflux-related cough and potential alternative approaches to therapy.

A causal relationship between cough and gastroesophageal reflux disease (GERD) has been established: a pro/con debate

Along with upper airway cough syndrome (formerly, postnasal drip syndrome) and eosinophilic airway inflammation (asthma, nonasthmatic eosinophilic bronchitis), gastroesophageal reflux disease (GERD) is generally considered among the most common etiologies of chronic cough. Indeed, cough management guidelines published by numerous respiratory societies worldwide recommend evaluation and treatment of GERD as an integral component of the diagnostic/therapeutic algorithm for the management of chronic cough. However, a significant number of patients with chronic cough presumed due to GERD do not report improvement despite aggressive acid-suppressive therapy. Some of these refractory cases may be due to the recently appreciated entity of nonacid or weakly acidic reflux. Further contributing to the controversy are recent studies that demonstrate that patients with chronic cough do not have excessive reflux events relative to healthy volunteers. Although a temporal relationship between cough and reflux events has been suggested by studies utilizing impedance-pH monitoring of reflux events and objective cough recording, consensus is lacking in terms of whether this temporal relationship proves a causal link between reflux and cough. The fourth American Cough Conference (New York, June 2013) provided an ideal forum for the debate of this issue between two internationally recognized experts in the field of reflux and chronic cough.

The oesophagus and cough: laryngo-pharyngeal reflux, microaspiration and vagal reflexes

Gastro-oesophageal reflux disease is generally considered to be one of the commonest causes of chronic cough, however randomised controlled trials of proton pump inhibitors have often failed to support this notion. This article reviews the most recent studies investigating the mechanisms thought to link reflux and cough, namely laryngo-pharyngeal reflux, micro-aspiration and neuronal cross-organ sensitisation. How recent evidence might shed light on the failure of acid suppressing therapies and suggest new approaches to treating reflux related cough are also discussed.

GERD-related cough: pathophysiology and diagnostic approach

Chronic cough is a common problem resulting in significant impairment of quality of life. Along with cough variant asthma and nasal disease, gastroesophageal reflux is considered one of three main causes of cough. Despite this, acid suppression therapy is often far from effective. This review aims to explore whether reflux can lead to cough, the circumstances in which this is most likely to occur, and the potential mechanisms linking these processes. Particular mechanisms to be explored include laryngopharyngeal reflux, microaspiration, and neuronal cross-organ sensitization. Finally, diagnostic approaches are considered.