Critical analysis of esophageal multichannel intraluminal impedance monitoring 20 years later

Insights into the Paradox of the Weak Association Between Sleeve Gastrectomy and Barrett's Esophagus

Sleeve gastrectomy (SG) is deemed a refluxogenic operation but with a low incidence of postoperative Barrett´s esophagus (BE). We aimed to shed some light on the potential paradox of the weak association between SG, BE and esophageal adenocarcinoma (EAC). The high incidence of GERD after SG is not followed by an increased rate of BE and EAC, as these rates are similar to the general population. We hypothesized that this paradox may occur due to a difference in the gastro-esophageal reflux composition secondary to a lower content of bile, to a decrease in inflammation due to weight loss and hormonal changes, and to acquisition of healthier habits such as exercise, smoking cessation, and better eating behavior.

Twenty-Four-Hour Esophageal pH Measurement in Mechanically Ventilated Children: A Prospective Cohort Study

OBJECTIVES

To assess the prevalence of gastroesophageal reflux in mechanically ventilated children using 24-hour esophageal pH-metry and its role as a risk factor for ventilator-associated pneumonia.

DESIGN

Prospective cohort study.

SETTING

PICU of a tertiary care hospital from North India.

PATIENTS

Mechanically ventilated children 1-15 years old in PICU from July 2015 to June 2017, excluding those receiving acid suppressants, known cases of gastroesophageal reflux disease, having upper gastrointestinal bleed.

INTERVENTION

Demographic details, baseline investigations, diagnosis, treatment details, and Pediatric Risk of Mortality III score were recorded at enrollment. Gastroesophageal reflux was evaluated using 24-hour esophageal pH-metry. Children were followed up for 7 days or 48 hours after extubation for development of ventilator-associated pneumonia using Centers for Disease Control and Prevention criteria. Pathologic acidic gastroesophageal reflux was defined as fall in esophageal pH less than 4 for more than 4% of total time, whereas pathologic alkaline gastroesophageal reflux as rise in esophageal pH greater than 7 for more than 17% of total time.

MEASUREMENTS AND MAIN RESULTS

Sixty-one children (median [interquartile range], age 73 mo [30-132 mo]; 44 boys [72%]) were enrolled. Median Pediatric Risk of Mortality III score was 10.0 (3-16). Median duration of ventilation was 6 days (3-9 d). Pathologic gastroesophageal reflux (acidic or alkaline) was present in 47 children (77%). Twelve children (19.7%) met criteria for pathologic acidic gastroesophageal reflux, whereas 44 children (72.1%) had pathologic alkaline gastroesophageal reflux; nine children (14.7%) had both pathologic acidic and alkaline gastroesophageal reflux. Of the enrolled children, 17 (27.9 %) developed ventilator-associated pneumonia. No patient had both pathologic acidic gastroesophageal reflux and ventilator-associated pneumonia. Of 17 children who developed ventilator-associated pneumonia, 12 (70.5%) had pathologic alkaline gastroesophageal reflux as compared to 32 children (72.7%) among the 44 children who did not develop ventilator-associated pneumonia (p = 0.87).

CONCLUSIONS

The current study shows high incidence of gastroesophageal reflux on 24-hour esophageal pH-metry in mechanically ventilated children with medical diagnoses. The significance of this finding and its impact on ventilator-associated pneumonia and other ventilator-associated events need to be examined in larger studies.

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.

Does DeMeester score still define GERD?

Gastroesophageal reflux disease (GERD) clinical presentation may encompass a myriad of symptoms that may mimic other esophageal and extra-esophageal diseases. Thus, GERD diagnosis by symptoms only may be inaccurate. Upper digestive endoscopy and barium esophagram may also be misleading. pH monitoring must be added often for a definitive diagnosis. The DeMeester score (DMS) is a composite score of the acid exposure during a prolonged ambulatory pH monitoring that has been used since 1970s to categorize patients as GERD+ or GERD-. We showed in this review that DMS has some limitations and strengths. Although there is not a single instrument to precisely diagnose GERD in all of its variances, pH monitoring analyzed at the light of DMS is still a reliable method for scientific purposes as well as for clinical decision making. There are no data that show that acid exposure time is superior-or for that matter inferior-as compared to DMS.

Advances in the Diagnosis of GERD Using the Esophageal pH Monitoring, Gastro-Esophageal Impedance-pH Monitoring, And Pitfalls

PH monitoring is not capable of detecting all types of reflux, especially when the amount of acid is very low or not at all in the refluxate. Multichannel intraluminal impedance-pH monitoring (MII-pH) is used as a new method to assess bolus transport. The types of reflexes including acid, weak acid and weak alkaline MII-pH is capable of distinguishing more reflux episodes based upon use of physical and chemical parameters of the refluxate, leads to a diagnosis of normal acid reflux from abnormal nonacidic reflux. 24-h oesophagal pH monitoring can be effectively used to assess the potential relationship between symptoms and refluxes. MII-pH is capable of distinguishing more reflux episodes based upon use of physical and chemical parameters of the refluxate, leads to a diagnosis of normal acid reflux from abnormal nonacidic reflux. It can be used to confirm gastro-oesophagal reflux episodes, where has a sensitivity and specificity for diagnosing GERD in comparison with endoscopy or pH-metry.

Dysphagia: Thinking outside the box

Dysphagia is a common symptom that is important to recognise and appropriately manage, given that causes include life threatening oesophageal neoplasia, oropharyngeal dysfunction, the risk of aspiration, as well as chronic disabling gastroesophageal reflux (GORD). The predominant causes of dysphagia varies between cohorts depending on the interplay between genetic predisposition and environmental risk factors, and is changing with time. Currently in white Caucasian societies adopting a western lifestyle, obesity is common and thus associated gastroesophageal reflux disease is increasingly diagnosed. Similarly, food allergies are increasing in the west, and eosinophilic oesophagitis is increasingly found as a cause. Other regions where cigarette smoking is still prevalent, or where access to medical care and antisecretory agents such as proton pump inhibitors are less available, benign oesophageal peptic strictures, Barrett's oesophagus, adeno- as well as squamous cell carcinoma are endemic. The evaluation should consider the severity of symptoms, as well as the pre-test probability of a given condition. In young white Caucasian males who are atopic or describe heartburn, eosinophilic esophagitis and gastroesophageal reflux disease will predominate and a proton pump inhibitor could be commenced prior to further investigation. Upper gastrointestinal endoscopy remains a valid first line investigation for patients with suspected oesophageal dysphagia. Barium swallow is particularly useful for oropharyngeal dysphagia, and oesophageal manometry mandatory to diagnose motility disorders.

The Clinical Value of Deflation Cough in Chronic Coughers With Reflux Symptoms

BACKGROUND

Patients with deflation cough (DC), the cough-like expulsive effort(s) evoked by maximal lung emptying during a slow vital capacity maneuver, also present symptoms of gastroesophageal reflux. DC can be inhibited by prior intake of antacids. We wished to assess DC prevalence and association between DC and chemical characteristics of refluxate in patients with gastroesophageal reflux symptoms.

METHODS

A total of 157 consecutive outpatients underwent DC assessment and 24-h multichannel intraluminal impedance pH (MII-pH) monitoring; 93/157 also had chronic cough. Patients performed two to four slow vital capacity maneuvers and DC was detected aurally. Subsequently, they underwent 24-h MII-pH monitoring, the outcomes of which were defined as abnormal when acid or non-acid reflux events were > 73.

RESULTS

DC occurred in 46/157 patients, 18 of whom had abnormal MII-pH outcomes; 28 of the remaining 111 patients without DC also had abnormal MII-pH findings. Thus, in the patients as a group, there was no association between DC and MII-pH outcomes. DC occurred in 40/93 of the chronic coughers; 15 of whom had acid reflux. All but 2 of the 53 patients without DC had normal MII-pH outcomes (P < .001), and the negative predictive value of DC for excluding acid reflux was 96.2%. At follow-up, 65% of coughers showed significant improvement after treatment.

CONCLUSIONS

The overall prevalence of DC was 29%, increasing to 43% in chronic coughers in whom the absence of DC virtually excludes acid reflux. Therefore, DC assessment may represent a useful screening test for excluding acid reflux in chronic coughers with reflux symptoms.

Novel esophageal speech therapy method in total laryngectomized patients: biofeedback by intraesophageal impedance

The loss of the best communication port after total laryngectomy surgery makes speech rehabilitation an important goal. Our aim was to improve the quality of esophageal speech (ES) using online esophageal multichannel intra-luminal impedance (MII) as a new biofeedback method. Twenty-six total laryngectomized patients were included. Before ES therapy, an esophageal motility test was carried out. MII catheters were placed in all subjects who were then randomized into two groups. Group 1 included 13 cases, who were retrained according to the classical method. Group 2 included 13 cases, who were retrained according to the simplified animation of air movements within the esophagus and upper stomach resulting from the modifications of intra-esophageal air kinetics gained by MII. The level of speech proficiency was evaluated relative to pretraining levels using perceptual scales in the third and sixth months. Acoustic voice was analyzed. The number of syllables read per minute and the intelligibility of monosyllabic and dissyllabic words were calculated. In this study, MII was used for the first time in alaryngeal speech rehabilitation as a biofeedback method; an overall sufficient speech level was achieved by 68.4% at the end of therapy, whereas attendance was 90%. A statistically significant improvement was found in both groups in terms of ES level compared with the pretraining period although there was no significant difference between groups. Although we did not observe the expected difference between groups suggested by our hypothesis, MII may be used as an objective tool to show patients how to swallow and regurgitate air during training, and may thus expedite ES therapy both for the speech therapist and the patient in the future.

Ratio between proximal/distal gastroesophageal reflux does not discriminate abnormal proximal reflux

INTRODUCTION

The threshold for pathologic proximal acid reflux is a controversial topic. Most values previously published are based on absolute numbers. We hypothesized that a relative value representing the quantitative relation between the amount of acid reflux that reaches proximal levels and the amount of distal reflux would be a more adequate parameter for defining pathologic proximal reflux.

METHODS

We studied 20 healthy volunteers (median age 30 years, 70 % women) without gastroesophageal reflux disease (GERD); 50 patients (median age 51 years, 60 % women) with esophageal symptoms of GERD (heartburn, regurgitation); and 50 patients (median age 49 years, 60 % women) with extra-esophageal symptoms of GERD. All individuals underwent manometry and dual-probe pH monitoring. GERD was defined as a DeMeester score >14.7. The proximal/distal reflux ratio was calculated for all six parameters that constitute the DeMeester score.

RESULTS

Absolute numbers for proximal reflux were not different for the three groups except for the number of episodes of reflux, which was higher for patients with GERD and esophageal symptoms than for patients with GERD and extra-esophageal symptoms (p = 0.007). The number of episodes of distal reflux reaching proximal levels was significantly higher in volunteers than in all patients with GERD and significantly higher in patients with GERD and esophageal symptoms than in those with extra-esophageal symptoms.

CONCLUSIONS

Our results suggest that the proximal/distal reflux ratio is not a good normative value for defining proximal reflux.