Reliability of oesophageal pH recording for the detection of gastro-oesophageal reflux

Normal values and regional differences in oesophageal impedance-pH metrics: a consensus analysis of impedance-pH studies from around the world

OBJECTIVE

Limitations of existing impedance-pH thresholds include small sample size of normative studies, inclusion of artefactual pH drops and incorrect identification of impedance reflux events. We aimed to obtain new impedance-pH thresholds from expert consensus analysis of tracings from a large number of healthy subjects.

DESIGN

Of 541 studies performed worldwide using two different systems (Diversatek, USA, and Laborie, Netherlands), 150 tracings with oesophageal diagnoses, behavioural disorders and study-related artefacts were excluded. The remainder studies were subject to two reviewer consensus analysis, in-person or through video conference, consisting of editing meals and pH drops, identification of impedance reflux and postreflux swallow-induced peristaltic wave (PSPW) using strict pre-established criteria and measurement of distal mean nocturnal baseline impedance (MNBI).

RESULTS

Consensus analysis was performed in 391 tracings (age 32.7 years, range 18-71, 54.2% female). Normative thresholds were significantly different between Diversatek and Laborie (total acid exposure time: 2.8% and 5%; reflux episodes: 55 and 78; MNBI at 3 cm: 1400 and 1500 ohms, at 5 cm: 1400 and 1800 ohms). Males had higher acid exposure, more reflux episodes and lower MNBI. Significant regional differences were identified, including higher PSPW scores in Western countries, and higher MNBI in Asia using Diversatek, and higher acid exposure in the Netherlands, higher MNBI in Asia and South Africa, and lower MNBI in Turkey using Laborie.

CONCLUSION

Normal impedance-pH monitoring thresholds have regional and system-related differences. Clinical interpretation needs to use normal thresholds valid for the system used and world region, following careful editing of the tracings.

Ambulatory reflux monitoring for diagnosis of gastro-esophageal reflux disease: Update of the Porto consensus and recommendations from an international consensus group

BACKGROUND

An international group of experts evaluated and revised recommendations for ambulatory reflux monitoring for the diagnosis of gastro-esophageal reflux disease (GERD).

METHODS

Literature search was focused on indications and technical recommendations for GERD testing and phenotypes definitions. Statements were proposed and discussed during several structured meetings.

KEY RESULTS

Reflux testing should be performed after cessation of acid suppressive medication in patients with a low likelihood of GERD. In this setting, testing can be either catheter-based or wireless pH-monitoring or pH-impedance monitoring. In patients with a high probability of GERD (esophagitis grade C and D, histology proven Barrett's mucosa >1 cm, peptic stricture, previous positive pH monitoring) and persistent symptoms, pH-impedance monitoring should be performed on treatment. Recommendations are provided for data acquisition and analysis. Esophageal acid exposure is considered as pathological if acid exposure time (AET) is greater than 6% on pH testing. Number of reflux episodes and baseline impedance are exploratory metrics that may complement AET. Positive symptom reflux association is defined as symptom index (SI) >50% or symptom association probability (SAP) >95%. A positive symptom-reflux association in the absence of pathological AET defines hypersensitivity to reflux.

CONCLUSIONS AND INFERENCES

The consensus group determined that grade C or D esophagitis, peptic stricture, histology proven Barrett's mucosa >1 cm, and esophageal acid exposure greater >6% are sufficient to define pathological GERD. Further testing should be considered when none of these criteria are fulfilled.

Gastroesophageal reflux disease: A clinical overview for primary care physicians

OBJECTIVE

GERD is among the most common outpatient disease processes encountered by clinicians on a daily basis. This review provides insights about how to approach GERD in terms of disease management and treatment.

METHODS

Review articles were searched using PUBMED and MEDLINE using criteria that included English language articles published in the last 5 years concerning studies carried out only in humans. The key words used in the searches were GERD, PPI, and erosive esophagitis. Recommendations from the American College of Gastroenterology are also included in this manuscript.

RESULTS

The search resulted in ∼260 articles. The manuscript brings together and presents the results of recent recommendations from professional societies and recently published review articles on GERD.

CONCLUSION

GERD is one of the most common diagnoses made by gastroenterologists and primary care physicians. It is important to recognize the typical and atypical presentations of GERD. This paper helps primary care physicians understand the disease's pathophysiology, and when, how, and with what to treat GERD before referring patients to gastroenterologists or surgeons.

Fundoplication for laryngopharyngeal reflux despite preoperative dysphagia

INTRODUCTION Fundoplication for laryngopharyngeal disease with oesophageal dysmotility has led to mixed outcomes. In the presence of preoperative dysphagia and oesophageal dysmotility, this procedure has engendered concern in certain regards. METHODS This paper describes a consecutive series of laryngopharyngeal reflux (LPR) patients with a high frequency of dysmotility. Patients were selected for surgery with 24-hour dual channel pH monitoring, oesophageal manometry and standardised reflux scintigraphy. RESULTS Following careful patient selection, 33 patients underwent fundoplication by laparoscopy. Surgery had high efficacy in symptom control and there was no adverse dysphagia. CONCLUSIONS Evidence of proximal reflux can select a group of patients for good results of fundoplication for atypical symptoms.

Comparison of the efficiencies of esophageal manometry, vector volume analysis and esophagus pH monitoring in the diagnosis of gastroesophageal reflux

AIM

In this study, we aimed to compare the superiorities of esophageal manometry, vector volume analysis and 24-hour pH meter studies in showing gastroesophageal reflux disease.

MATERIAL AND METHODS

The files of the patients who presented to pediatric surgery and pediatric gastroenterology outpatient clinics of our hospital with suspicious gastroesophageal reflux disease between 2011 and 2012 and who were investigated were examined and 21 patients whose investigations had been completed were included in the study. The patients were evaluated by treatment method and were divided into three groups as Group 1 who were followed up with medical treatment, Group 2 in whom surgical intervention was performed and Group 3 who were not treated. Chi-square test was used in evaluation of the categorical variables, Kruskal Wallis test was used in comparison of the mean values between the groups and Dunn test was used in subgroup analyses when Kruskal Wallis test was found to be significant. A p value of <0.05 was considered statistically significant.

RESULTS

Thirteen of 21 patients included in the study were female and eight were male. The mean age of the patients was 5.71 years (one-16 years). In the 24-hour pH monitoring study, the mean reflux index was found to be 48.7% in Group 1, 42.4% in Group 2 and 28.3% in Group 3. In esophageal manometry studies, the pressure difference at lower esophageal sphincter (LES) was found to be 13,4 cm H2O in Group 1, 31.8 cm H2O in Group 2 and 4.3 cmH2O in Group 3. In vector volume analyses, the mean vector volume was calculated to be 96.01 cm(3) in Group 1, 2 398.9 cm(3) in Group 2 and 196.3 cm(3) in Group 3. In the 24-hour pH monitoring study, a statistically significant difference (p<0.05) was found in terms of showing reflux, whereas statistical significance could not be shown in terms of need for surgical treatment or need for medical treatment in any other method (p>0.05).

CONCLUSIONS

Twenty-four-hour pH monitoring was found to be efficient in making a diagnosis of gastroesophageal reflux disease, whereas esophageal manometry and vector volume analyses were not found to be efficient.

Scintigraphy in laryngopharyngeal and gastroesophageal reflux disease: A definitive diagnostic test?

AIM: To investigate the utility of scintigraphic studies in predicting response to laparoscopic fundoplication (LF) for chronic laryngopharyngeal reflux symptoms.

METHODS: Patients with upper aero-digestive symptoms that remained undiagnosed after a period of 2 mo were studied with conventional pH and manometric studies. Patients mainly complained of cough, sore throat, dysphonia and globus. These patients were imaged after ingestion of 99m-technetium diethylene triamine pentaacetic acid. Studies were quantified with time activity curves over the pharynx, upper and lower oesophagus and background. Late studies of the lungs were obtained for aspiration. Patients underwent LF with post-operative review at 3 mo after surgery.

RESULTS: Thirty four patients (20 F, 14 M) with an average age of 57 years and average duration of symptoms of 4.8 years were studied. Twenty four hour pH and manometry studies were abnormal in all patients. On scintigraphy, 27/34 patients demonstrated pharyngeal contamination and a rising or flat pharyngeal curve. Lung aspiration was evident in 50% of patients. There was evidence of pulmonary aspiration in 17 of 34 patients in the delayed study (50%). Pharyngeal contamination was found in 27 patients. All patients with aspiration showed pharyngeal contamination. In the 17 patients with aspiration, graphical time activity curve showed rising activity in the pharynx in 9 patients and a flat curve in 8 patients. In those 17 patients without pulmonary aspiration, 29% (5 patients) had either a rising or flat pharyngeal graph. A rising or flat curve predicted aspiration with a positive predictive value of 77% and a negative predictive value of 100%. Over 90% of patients reported a satisfactory symptomatic response to LF with an acceptable side-effect profile.

CONCLUSION: Scintigraphic reflux studies offer a good screening tool for pharyngeal contamination and aspiration in patients with gastroesophageal reflux disease.

Clinical applications of esophageal impedance monitoring and high-resolution manometry

Esophageal impedance monitoring and high-resolution manometry (HRM) are useful tools in the diagnostic work-up of patients with upper gastrointestinal complaints. Impedance monitoring increases the diagnostic yield for gastroesophageal reflux disease in adults and children and has become the gold standard in the diagnostic work-up of reflux symptoms. Its role in the work-up for belching disorders and rumination seems promising. HRM is superior to other diagnostic tools for the evaluation of achalasia and contributes to a more specific classification of esophageal disorders in patients with non-obstructive dysphagia. The role of HRM in patients with dysphagia after laparoscopic placement of an adjustable gastric band seems promising. Future studies will further determine the clinical implications of the new insights which have been acquired with these techniques. This review aims to describe the clinical applications of impedance monitoring and HRM.

Detection of gastro-oesophageal reflux disease (GORD) in patients with obstructive lung disease using exhaled breath profiling

Gastro-oesophageal reflux disease (GORD) has been implicated in the worsening of several respiratory disorders. Current methods of diagnosis lack accuracy, are invasive and can be costly. Recently, novel methods of analysing lung pathophysiology have been developed including the use of an electronic nose and analysis of components of exhaled breath condensate (EBC). We hypothesised that these methods would distinguish patients with GORD from those without GORD in the common obstructive lung diseases and healthy controls. In a cross-sectional study, exhaled breath was analysed using the Cyranose 320 electronic nose, using principal components and canonical discriminant analyses. EBC pH and pepsin were quantified using a pH meter and an enzyme-linked immunosorbent assay, respectively. A standardized reflux disease questionnaire (RDQ) was used to assess reflux symptoms. The Cyranose 320 distinguished exhaled breath profiles of obstructive lung disease patients without GORD from obstructive lung disease patients with GORD (p = 0.023, accuracy 67.6%), asthmatic patients with reflux from asthmatics without GORD (85%, p = < 0.015, interclass M distance > 2.8), but did not produce as robust a profile for patients with COPD and COPD with GORD (p = 0.047, accuracy 64%). Patients with obstructive lung disease and GORD had significantly higher levels of EBC pepsin (9.81 ± interquartile range (IQR) 4.38 ng ml(-1)) than those without GORD (4.6 ± IQR 6.95 ng ml(-1)), as well as healthy controls (3.44 ± IQR 7.87 ng ml(-1); p = < 0.013). EBC pH was not significantly related to the presence of GORD in any group. The RDQ results correlated significantly with the presence of EBC pepsin. This pilot study has shown that exhaled breath profiling can be used for detecting GORD in obstructive lung diseases. While the electronic nose was useful in asthma, EBC pepsin was more helpful in COPD. In this study, several different confounders could potentially have affected results and larger prospective interventional studies are needed.

Diagnosing GORD in Respiratory Medicine

Gastroesophageal reflux disease (GORD) is increasing in prevalence and is highly associated with several lung diseases such as asthma and COPD. Current diagnostic methods are imperfect, being insensitive, non-specific, expensive, or invasive. An accurate diagnosis of GORD can aid effective treatment and have significant clinical impact. Novel methods such as exhaled breath condensate analysis and electronic nose technology have the potential to improve the accuracy of diagnosing GORD.

Systematic review: role of acid, weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease

BACKGROUND

The importance of weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease (GERD) is gaining recognition.

AIM

To quantify the proportions of reflux episodes that are acidic (pH <4), weakly acidic (pH 4-7) and weakly alkaline (pH >7) in adult patients with GERD, and to evaluate their correlation with symptoms.

METHODS

Studies were identified by systematic PubMed and Embase searches. Data are presented as sample-size weighted means and 95% confidence intervals.

RESULTS

In patients with GERD taking a proton pump inhibitor (PPI), 80% (76-84%) of reflux episodes were weakly acidic or weakly alkaline and 83% (78-88%) of reflux symptom episodes were associated with weakly acidic or weakly alkaline reflux episodes. In patients with GERD not taking a PPI, 63% (59-67%) of reflux episodes were acidic and 72% (57-87%) of reflux symptom episodes were associated with acid reflux episodes. Six studies presented data separately for weakly alkaline reflux, which accounted for <5% of all reflux episodes, both on and off PPI therapy.

CONCLUSIONS

Weakly acidic reflux underlies the majority of reflux episodes in patients with GERD on PPI therapy, and is the main cause of reflux symptoms occurring despite PPI therapy.