Reproducibility of symptom association analysis in ambulatory reflux monitoring

INTRODUCTION

The temporal relationship between reflux symptoms and reflux episodes during ambulatory reflux monitoring can be studied with symptom association analysis, and the strength of the relationship can be expressed using indices such as the SAP (symptom association probability), SI (symptom index), and SSI (symptom sensitivity index). The reproducibility of these indices has not been determined yet.

METHOD

Twenty-one patients with typical reflux symptoms (9 men, 53 [38-57] yr) underwent two 24-h combined pH-impedance recordings off acid-secretory medication with an interval of 1-4 wk. The SAP, SI, and SSI were calculated for each measurement. Reproducibility of these indices was determined with Kendall's coefficients of concordance.

RESULTS

The number of reflux events were highly reproducible (Kendall W = 0.92, P < 0.01). The number of symptoms related to reflux events was reproducible (Kendall W = 0.91, P < 0.01) while the number of reported reflux symptoms was not (Kendall W = 0.75, P= 0.07). The SAP and SSI were highly reproducible (Kendall W = 0.90, P= 0.01, and W = 0.86, P < 0.05, respectively) but the SI was not (W = 0.73, P= 0.09). The percentage of patients with similar outcomes on two separate test days for the SAP, SI, and SSI was 86%, 67%, and 86%, respectively.

DISCUSSION

In 24-h pH-impedance recordings of patients with reflux symptoms, the number of reflux events and the number of symptoms related to reflux events were highly reproducible as were the SAP and SSI. This supports the use of these indices to express the relationship between symptoms and reflux episodes in clinical practice.

Impedance-pH monitoring: new standard for measuring gastro-oesophageal reflux

Impedance monitoring is a new technique that can be used to detect the flow of fluids and gas through hollow viscera. With impedance monitoring gastro-oesophageal reflux can be detected independent of its acidity by differences in electrical impedance between the mucosal surface, fluids and gas that surround the catheter. Clinically, it is used in combination with oesophageal pH monitoring, and the combination of impedance-pH monitoring allows recognition of both acidic and weakly acidic reflux episodes. Studies have shown that impedance-pH monitoring is useful in the evaluation of patients with proton pump inhibitor-resistant typical reflux symptoms, as it provides a higher yield in detecting reflux as the cause of a patient's symptoms compared to pH monitoring alone. It is therefore likely that impedance-pH monitoring will largely replace pH monitoring in the next 5 years and it will become the standard for reflux detection.

Oesophageal high-resolution manometry: moving from research into clinical practice

Manometry measures pressure within the oesophageal lumen and sphincters, and provides an assessment of the neuromuscular activity that dictates function in health and disease. It is performed to investigate the cause of functional dysphagia, unexplained "non-cardiac" chest pain, and in the pre-operative work-up of patients referred for anti-reflux surgery. Manometric techniques have improved in a step-wise fashion from a single pressure channel to the development of high-resolution manometry (HRM) with up to 36 pressure sensors. At the same time, advances in computer processing allow pressure data to be presented in real time as a compact, visually intuitive "spatiotemporal plot" of oesophageal pressure activity. HRM recordings reveal the complex functional anatomy of the oesophagus and its sphincters. Spatiotemporal plots provide objective measurements of the forces that move food and fluid from the pharynx to the stomach and determine the risk of reflux events. The introduction of commercially available HRM has been followed by rapid uptake of the technique. This review examines the current evidence that supports the move of HRM from the research setting into clinical practice. It is assessed whether a detailed description of pressure activity identifies clinically relevant oesophageal dysfunction that is missed by conventional investigation, increasing diagnostic yield and accuracy. The need for a new classification system for oesophageal motor activity based on HRM recordings is discussed. Looking ahead the potential of this technology to guide more effective medical and surgical treatment of oesophageal disease is considered because, ultimately, it is this that will define the success of HRM in clinical practice.

Mechanisms of acid, weakly acidic and gas reflux after anti-reflux surgery

BACKGROUND

Whereas it is well documented that fundoplication reduces acid reflux, the effects of the procedure on non-acid and gas reflux and the mechanisms through which this is achieved have not been fully elucidated.

METHODS

In 14 patients, reflux was measured with impedance-pH monitoring during a postprandial 90 min stationary recording period before and 3 months after fundoplication. Concomitantly, the occurrence of transient lower oesophageal sphincter relaxations (TLOSRs) and morphology of the oesophagogastric junction were studied with high-resolution manometry. This was followed by 24 h ambulatory impedance-pH monitoring.

RESULTS

Before fundoplication, two separate high-pressure zones (hernia profile) were detected during 24.9% of total time, during which there was a large increase in reflux rate. After fundoplication, the hernia profile did not occur. Fundoplication decreased the number of TLOSRs (from 10.5 (SEM 1.2) to 4.5 (0.7), p<0.01) and also the percentage of TLOSRs associated with acidic or weakly acidic reflux (from 72.7% to 4.1%, p<0.01). Nadir pressure during TLOSRs increased after surgery (from 0 (0-0) to 1.0 (1-2) kPa, p<0.05). In the ambulatory study, there was a large decrease in prevalence of both acid (-96%, from 47.0 (5.9) to 1.8 (0.5), p<0.01) and weakly acidic reflux (-92%, from 25.0 (9.7) to 2.3 (0.9), p<0.01). The decrease in gas reflux was less pronounced (-53%, from 24.2 (4.9) to 11.3 (3.0), p<0.01).

CONCLUSIONS

Fundoplication greatly reduces both acid and weakly acidic liquid reflux; gas reflux is reduced to a lesser extent. Three mechanisms play a role: (1) abolition of the double high-pressure zone profile (hiatal hernia); (2) reduced incidence of TLOSRs; and (3) decreased percentage of TLOSRs associated with reflux.

[Sigmoid carcinoma as a long-term complication following ureterosigmoidostomy]

A 45-year-old woman, known to have a congenital exstrophy ofthe bladder, for which she underwent a ureterosigmoidostomy in her infancy, presented with fever. This was due to pyelonephritis, from which she recovered with antibiotic therapy. During colonoscopy a carcinoma of the sigmoid was found at the level of the anastomosis of the ureters. Patients with a ureterosigmoidostomy have a one hundred-fold increased risk of colon carcinoma compared to the general population. The development of malignant tumours as a long-term complication of this procedure is linked with the frequent contact between intestinal tissue and urine. Periodical colonoscopy of these patients is advised.

High-resolution manometry of the esophagus: more than a colorful view on esophageal motility?

Since the introduction of pressure measurement of the esophagus, there has been a stepwise improvement in manometric techniques and the recognition of esophageal manometry as a useful tool to evaluate esophageal function in clinical practice. The newest development in this field is high-resolution manometry of the esophagus. In this review, we will briefly discuss the indications for esophageal manometry and we will focus on the development of the technique of high-resolution manometry and the new insights that were obtained by using this emerging tool. We conclude that high-resolution esophageal manometry with spatiotemporal plotting of signals is a valuable research tool. Clinically, the solid-state high-resolution technique is attractive because it makes it easy to perform a high-quality manometric test. However, future studies will have to determine whether the yield of the technique is higher than that of conventional manometry.

Physiologic and pathologic belching

Accumulation of air in the stomach increases gastric volume, which activates receptors in the gastric wall. A reflex is initiated, leading to relaxation of the lower esophageal sphincter, upward movement of the air through the esophagus, and finally passage through the upper esophageal sphincter, during which an audible belch can sometimes be heard. Excessive belching is often reported in patients with gastroesophageal reflux disease and functional dyspepsia. Often other symptoms are predominant, and these should be treated first. Sometimes patients present with excessive belching as an isolated symptom. These patients belch in very high frequencies, up to 20 times per minute, and often during consultation. This condition is referred to as aerophagia. In these patients air is sucked into the esophagus or injected by pharyngeal contraction, after which it is expelled immediately. Aerophagia is a behavioral disorder, and behavioral therapy and/or speech therapy seems to be the therapy of choice.

Air swallowing, belching, acid and non-acid reflux in patients with functional dyspepsia

BACKGROUND

Frequent belching is a common symptom in patients with functional dyspepsia with a reported incidence up to 80%. We hypothesized that patients with functional dyspepsia possibly have a higher frequency of belching than healthy subjects secondary to frequent air swallowing.

AIM

To assess air swallowing, belching, acid and non-acid reflux patterns of patients with functional dyspepsia.

METHODS

Combined 24-h oesophageal impedance and pH monitoring was performed in 10 functional dyspepsia patients and 10 controls. Analysis of the impedance-pH signals included incidence of air swallows, belching, acid and non-acid reflux.

RESULTS

The incidence of air swallows in functional dyspepsia patients were significantly higher compared with controls (153 +/- 15 vs. 79 +/- 10, P < 0.001), while the incidence of liquid-only swallows were not significantly increased. The proportions of gas-containing reflux episodes (belches) and non-acid reflux episodes in functional dyspepsia patients were significantly higher when compared with controls (66.4 vs. 44.4%, P = 0.04 and 70.1 vs. 45.9%, P = 0.009, respectively).

CONCLUSION

Patients with functional dyspepsia swallow air more frequently than controls and this is associated with an increased incidence of non-acid gaseous gastro-oesophageal reflux.

Technology review: Esophageal impedance monitoring

Intraluminal impedance monitoring is a new technique that can be used to detect the flow of liquids and gas through hollow viscera. In combination with manometry, it is used for esophageal function testing and while manometry provides information on contractile activity, impedance provides information on esophageal bolus transit. This is especially useful in patients with nonobstructive dysphagia. However, impedance monitoring appears to be less suitable for the evaluation of patients with achalasia. When used in combination with esophageal pH monitoring, impedance monitoring makes gastroesophageal reflux monitoring more complete because it allows recognition of both acidic and weakly acidic reflux episodes. The results of several studies suggest that impedance-pH monitoring is useful in the evaluation of patients with PPI-resistant typical reflux symptoms, chronic unexplained cough, excessive belching, and rumination.

Psychological factors affect the frequency of belching in patients with aerophagia

BACKGROUND

In patients with aerophagia and excessive belching an organic cause is seldom found and a psychogenic cause is often suspected.

AIM

To investigate the effects of attention and distraction on the frequency of belching in patients with aerophagia.

METHODS

In 10 patients with aerophagia, combined esophageal manometry and impedance monitoring was performed for 2 h, consisting of four 30-minute recording periods. Period I: patient unaware that recording had commenced. Period II: patient informed of recording in progress. Period III: distraction by filling in questionnaires. Period IV: no distraction.

RESULTS

A total of 1,258 belches was measured, 51 of which were the result of air that escaped from the stomach (gastric belches). A total of 1,207 belches (96%) were events during which air was expelled in the oral direction almost immediately after entering the esophagus from there (supragastric belches). Gastric belches were distributed equally over the first (1.5 [0.5-2.0]), second (1.5 [0.5-2.0]), third (1.0 [0-2.0]), and fourth (1.0 [0-2.0]) recording periods. In contrast, the incidence of supragastric belches increased significantly from 0 (0-32) in period I to 30 (18-60) in period II, after patients were told that recording was started. During period III (questionnaires) the incidence of supragastric belches decreased to 14 (4-30). In period IV the incidence of supragastric belches increased to 21 (10-49).

CONCLUSIONS

When patients with excessive belching are unaware that they are being studied or when they are distracted, the incidence of belching is significantly reduced. These findings underline the importance of psychological factors and provide rationale for behavioral therapy.

The gastro-oesophageal common cavity revisited

The manometric common cavity phenomenon has been used as indicator of gastro-oesophageal reflux of liquid or gaseous substances. Using combined pH and impedance recording as reference standard the value of a common cavity as indicator of gastro-oesophageal reflux was tested. Ten healthy male subjects underwent combined stationary pressure, pH and impedance recording for 4.5 h. After 1.15 h of recording, a reflux-eliciting meal was consumed. The chi-squared and Kolmogorov-Smirnov tests were used for the statistical analysis. A common cavity was found in 95 (43%) of the 223 reflux events detected by impedance, while seven common cavities were unrelated to a reflux episode. In 54% of the reflux events detected by impedance without a common cavity, a possible common cavity was obscured by either contractile activity or artefacts of various origin. The types of reflux associated with a common cavity (liquid 60%, mixed 31%, gas 9%) and without a common cavity (liquid 59%, mixed 29%, gas 12%) did not differ, or did the acidity of the reflux episodes (with common cavity: acid 67%; without common cavity: acid 58%). The common cavity is a specific but not a sensitive marker of gastro-oesophageal reflux. Furthermore, common cavities are not specific for a particular type of reflux.

Characteristics of gastroesophageal reflux in symptomatic patients with and without excessive esophageal acid exposure

OBJECTIVE

In some patients with a physiological esophageal acid exposure, an association between reflux episodes and symptoms can be demonstrated. Besides acidity, other factors such as proximal extent may determine whether a reflux episode is perceived or not. We aimed to investigate the reflux profile of gastroesophageal reflux disease (GERD) patients with physiological acid exposure.

METHODS

Twenty-four-hour impedance-pH monitoring was performed in 14 GERD patients with excessive acid exposure (pH+), 14 GERD patients with physiological acid exposure (pH-), and 14 controls. All patients had a positive symptom-reflux association during 24-h monitoring (SAP+).

RESULTS

The incidence of acid reflux episodes in pH- SAP+ patients (25.5 +/- 4.9) and controls (20.2 +/- 3.9) was comparable, but lower than in pH+ SAP+ patients (69.8 +/- 7.3). However, no differences in number of weakly acidic reflux episodes were observed among pH- SAP+ patients, pH+ SAP+ patients, and controls (27.2 +/- 3.8 vs 26.8 +/- 4.6 and 21.0 +/- 3.7, respectively). The proportion of reflux episodes that reached the proximal esophagus was significantly higher in the pH+ SAP+ (33.5%) and pH- SAP+ (36.0%) patients than in the controls (19.5%). Volume clearance time was longer in pH+ SAP+ (12.5 [12.5-17.0] s) compared with pH- SAP+ patients (12.0 [11.0-16.5] s) and controls (9.5 [10.0-12.5] s) (P < 0.05). Acid clearance time was also longer in pH+ SAP+ patients (55.0 [32.0-64.0] s) compared with the pH- SAP+ (16.5 [11.4-40.0] s) and controls (14 [12.0-19.1] s) (P < 0.01).

CONCLUSIONS

In pH- SAP+ patients, a higher proportion of reflux episodes reach the proximal esophagus than in controls. This can in part explain their symptoms.

Assessment of oesophageal emptying in achalasia patients by intraluminal impedance monitoring

Oesophageal emptying can be assessed by radiographic and scintigraphic tests with radiation exposure or by multichannel intraluminal impedance monitoring (MII). The aim of this study was to evaluate the applicability of MII for the assessment of oesophageal emptying in achalasia patients. In 10 achalasia patients, impedance tracings were scored independently by three observers after ingestion of a 100-mL barium bolus. Bolus clearance time (BCT) and height of barium column were scored using fluoroscopic images acquired at 20-s intervals. All patients showed a low baseline impedance level in the distal oesophagus. Air trapping in the proximal oesophagus was detected in nine patients. BCT on MII was similar to that on fluoroscopy in 40-70% of the patients. Correlations between height of barium on fluoroscopy and fluid level on MII were poor to moderate at different time intervals. Concordance (Kendall's coefficient) between the three observers for assessment of fluid level on MII was 0.31 (P = 0.04) at 1 and 5 min, 0.26 (P = 0.08) at 10 and 0.44 (P = 0.01) at 15 min. We conclude that in achalasia patients, low baseline impedance levels and air entrapment in the proximal oesophagus limit the value of intraluminal impedance monitoring as a test of oesophageal emptying.

Effect of dietary sodium chloride on gastro-oesophageal reflux: a randomized controlled trial

OBJECTIVE

It has been suggested that a high consumption of sodium chloride (NaCl) is associated with reflux symptoms. The objective of this study was to investigate the effect of increased dietary NaCl intake on gastro-oesophageal reflux and reflux mechanisms.

MATERIAL AND METHODS

In this double-blind, placebo-controlled, crossover study 10 healthy male subjects received 5 g NaCl or placebo in capsules per day for one week, after which concurrent manometric, pH and impedance monitoring was carried out for 4.5 h.

RESULTS

Oesophageal acid exposure time (pH < 4) was similar for placebo (median 11% (25th 3-75th 36)) and NaCl (9% (1-36)). No differences in the numbers of reflux episodes were found for NaCl (16 (13.5-22)) and placebo (23 (14.8-27)). Furthermore, similar numbers of liquid acid reflux episodes (placebo 12 (6.5-17.3); NaCl 10 (2.3-14.3)), liquid weakly acidic reflux episodes (placebo 5.5 (4-12.3); NaCl 6.5 (3-10.8)) and gaseous reflux episodes (placebo 1 (0-1.8); NaCl 2 (0-3)) were seen. In both conditions transient lower oesophageal sphincter relaxations (TLOSRs) were the most common reflux mechanism, followed by swallow-induced reflux. High salt intake lowered LOS pressure overall and in the first postprandial hour (p<0.01).

CONCLUSIONS

High dietary sodium intake does not increase gastro-oesophageal reflux in healthy volunteers, despite a decrease in LOS pressure.

Gastro-oesophageal reflux of liquids and gas during transient lower oesophageal sphincter relaxations

Some transient lower oesophageal sphincter relaxations (TLOSRs) are accompanied by gastro-oesophageal reflux and others are not. We aimed to investigate what factors determine the occurrence and type of reflux during TLOSRs. In 12 healthy subjects prolonged high-resolution manometry was performed. Reflux was detected using pH-impedance monitoring. A total of 219 TLOSRs were detected; no differences were observed between the duration of TLOSRs with liquid-containing reflux (20.2 +/- 1.0 s), gas reflux (17.0 +/- 1.0 s) and no reflux (19.0 +/- 1.0 s). Trans-sphincteric pressure gradient was similar in TLOSRs with liquid reflux (1.6 +/- 0.1 kPa), gas reflux (1.5 +/- 0.1 kPa) and no reflux (1.7 +/- 0.3 kPa). Prevalence, duration and amplitude of oesophageal pre-contractions and sphincteric after-contractions were not different for TLOSRs with and without reflux. The total number of TLOSRs decreased significantly from 8.2 +/- 0.8 in the first to 5.7 +/- 0.5 in the second and 4.4 +/- 0.6 in the third 70-min recording period. The number of TLOSRs accompanied by liquid-containing reflux decreased from 4.7 +/- 0.9 to 3.0 +/- 0.4 to 1.6 +/- 0.4, while the numbers of TLOSRs with gas reflux remained unchanged (2.1 +/- 0.6-2.1 +/- 0.7-2.2 +/- 0.6). Besides, time after the meal, no differences were observed in the characteristics of TLOSRs with and without gastro-oesophageal reflux. We conclude that factors, other than TLOSR characteristics, are important of whether or not a TLOSR is reflux-related.

Air swallowing, belching, and reflux in patients with gastroesophageal reflux disease

OBJECTIVES

Belching and gastroesophageal reflux share a common physiological mechanism. The aim of this study was to investigate whether air swallowing leads to both belching and reflux.

METHODS

Esophageal impedance, pH, and pressure were measured during two 20-min recording periods in 12 controls and 12 patients with gastroesophageal reflux disease (GERD), before and after intragastric inflation of 600 mL of air. This was repeated after a meal. Subsequently, ambulatory 24-h impedance-pH measurement was performed.

RESULTS

During the 24-h study, patients showed a higher incidence of air swallows (287 +/- 45 vs 176 +/- 24, p < 0.05), belches (52.4 +/- 6.6 vs 32.7, p < 0.01), and acid reflux (42.3 +/- 7.6 vs 19.1 +/- 2.8, p < 0.01) than controls. After air infusion the incidence of gas reflux episodes was increased, both in patients (0.58 +/- 0.36 vs 3.50 +/- 0.61, p < 0.01) and in controls (0.75 +/- 0.67 vs 4.08 +/- 0.59, p < 0.01). In contrast, the incidence of acid and weakly acidic reflux episodes was not increased after air infusion, neither in patients (acid: 1.25 +/- 0.37 vs 1.20 +/- 0.33, weakly acidic: 1.08 +/- 0.40 vs 0.80 +/- 0.23) nor in controls (acid: 0.72 +/- 0.34 vs 0.50 +/- 0.23, weakly acidic: 0.80 +/- 0.35 vs 0.33 +/- 0.19). Air infusion increased transient lower esophageal sphincter relaxations (TLESR) frequency in patients and controls, but this was entirely because of an increase in gas reflux-associated TLESRs.

CONCLUSIONS

Patients with GERD swallow air more frequently and belch more frequently than healthy subjects. However, air swallowing is not the cause of their increase in reflux.

Aerophagia and rumination: Recognition and therapy

Aerophagia and rumination syndrome are functional upper gastrointestinal disorders that are becoming increasingly recognized in otherwise-healthy children and adults. Aerophagia is primarily characterized by troublesome repetitive belching and abdominal symptoms that result from air sucking and swallowing. Rumination syndrome is primarily characterized by regurgitation occurring shortly after meal intake. Physiologic studies suggest that both disorders are a result of habitual behavior with associated esophageal and gastric physiologic deviations. However, the underlying etiology of these disorders remains unclear. Studies examining optimal treatments are lacking. However, therapeutic approaches utilizing biofeedback may be helpful in alleviating symptoms for patients with these conditions.

[Belching (ructus)]

Accumulation of air in the stomach increases the gastric volume, which activates receptors in the gastric wall. This results in a reflex that relaxes the lower oesophageal sphincter, whereby the intragastric air can escape through the oesophagus. Ventilation of the stomach via the oesophagus is known as belching (ructus). Belching often occurs in combination with reflux symptoms and dyspepsia. In these cases, other symptoms are often more predominant, and it is advisable to treat these first. In patients with aerophagia, belching is the most common reason for medical consultation. These patients belch frequently, up to 20 times per minute, and often during consultation. Aerophagia results from air being sucked into the oesophagus or injected by pharyngeal contraction, after which it is expelled immediately. In contrast to the described gastric belching, aerophagia is therefore a form of supragastric belching. Aerophagia is a behavioural disorder, and behavioural therapy or logopedics appears to be most common therapeutic approach.

Addition of esophageal impedance monitoring to pH monitoring increases the yield of symptom association analysis in patients off PPI therapy

BACKGROUND

The additional yield of esophageal impedance monitoring in identification of reflux as the cause of reflux symptoms is unknown.

OBJECTIVES

To compare the yield of symptom-reflux association analysis of combined esophageal pH-impedance data with the yield of analysis of pH data alone.

METHODS

In 60 patients with symptoms of heartburn and regurgitation combined, 24-h pH-impedance monitoring was performed. Acid-suppressive medication was stopped 1 wk in advance. Patients (48) with at least one symptom during the measurement period were selected for further analysis. Patients were instructed to note the time and nature of their symptoms. Eleven types of reflux episodes were defined, based on combinations of magnitude of the pH drop, nadir pH, and nature of the refluxate (gas and liquid) on impedance tracings. Symptom association analysis-symptom index, the symptom sensitivity index, and the symptom association probability (SAP)-was performed for each definition of reflux.

RESULTS

The proportion of patients with a positive SAP (> or =95.0%) varied between 62.5% and 77.1%, depending on the definition of reflux episodes. When both pH and impedance parameters were used to identify reflux, a higher proportion of patients had a positive SAP than with pH alone (77.1%vs 66.7%, p < 0.05). Symptom association analysis for acidic and weakly acidic reflux separately did not result in a higher yield than analysis with all reflux episodes pooled, regardless of pH.

CONCLUSION

In patients off proton pump inhibitor, the addition of impedance monitoring to esophageal pH monitoring leads to an increase in the proportion of patients in whom an association between reflux episodes and symptoms can be identified.

Determinants of perception of heartburn and regurgitation

BACKGROUND AND AIMS

It is not known why some reflux episodes evoke symptoms and others do not. We investigated the determinants of perception of gastro-oesophageal reflux.

METHODS

In 32 patients with symptoms suggestive of gastro-oesophageal reflux, 24 hour ambulatory pH and impedance monitoring was performed after cessation of acid suppressive therapy. In the 20 patients who had at least one symptomatic reflux episode, characteristics of symptomatic and asymptomatic reflux episodes were compared.

RESULTS

A total of 1807 reflux episodes were detected, 203 of which were symptomatic. Compared with asymptomatic episodes, symptomatic episodes were associated with a larger pH drop (p<0.001), lower nadir pH (p<0.05), and higher proximal extent (p<0.005). Symptomatic reflux episodes had a longer volume and acid clearance time (p<0.05 and p<0.002). Symptomatic episodes were preceded by a higher oesophageal cumulative acid exposure time (p<0.05). The proximal extent of episodes preceding regurgitation was larger than those preceding heartburn; 14.8% of the symptomatic reflux episodes were weakly acidic. In total, 426 pure gas reflux episodes occurred, of which 12 were symptomatic. Symptomatic pure gas reflux was more frequently accompanied by a pH drop than asymptomatic gas reflux (p<0.05).

CONCLUSIONS

Heartburn and regurgitation are more likely to be evoked when the pH drop is large, proximal extent of the refluxate is high, and volume and acid clearance is delayed. Sensitisation of the oesophagus occurs by preceding acid exposure. Weakly acidic reflux is responsible for only a minority of symptoms in patients off therapy. Pure gas reflux associated with a pH drop ("acid vapour") can be perceived as heartburn and regurgitation.

Intermittent spatial separation of diaphragm and lower esophageal sphincter favors acidic and weakly acidic reflux

BACKGROUND & AIMS

In small hiatal hernias, the size of the hernia is variable. Intermittent complete reduction can be observed with high-resolution manometry as a transition from a double-peak (hernia) to a single-peak (reduced) high-pressure zone. The aim of this study was to investigate whether intermittent separation of the diaphragm and lower esophageal sphincter (LES) favors the occurrence of gastroesophageal reflux.

METHODS

In 16 patients with a small hiatal hernia (3 cm), prolonged high-resolution manometry was performed. Acid and weakly acidic reflux episodes were detected with pH-impedance monitoring.

RESULTS

The single pressure peak profile (reduced hernia) was present for 814 minutes (56.5% of total time), and the double peak profile (unreduced hernia) was present for 626 minutes (43.5% of total time). In all patients, both pressure profiles were observed. The transition rate between the 2 profiles was 7.5 +/- 0.9 per hour. More reflux occurred when the LES and diaphragm were separated versus the reduced hernia state (23.1 +/- 5.1 vs 12.2 +/- 2.4 episodes per hour, respectively; P < .05). The proportions of acidic reflux episodes during the single and double pressure peaks were similar (70% and 67%, respectively). In the two-pressure-zone state, there was an increase in all reflux mechanisms except transient LES relaxation.

CONCLUSIONS

In patients with a small hiatal hernia, intermittent reduction of the hernia occurs frequently. Spatial separation of the diaphragm and LES in the nonreduced state results in a 2-fold increase in acidic and weakly acidic reflux due to mechanisms other than transient LES relaxation.

Aerophagia in adults: a comparison with functional dyspepsia

BACKGROUND

Aerophagia is a functional upper gastrointestinal disorder that has not previously been well described in a large patient group.

AIMS

To describe the initial evaluation of patients who presented with symptoms of aerophagia at a tertiary medical centre.

METHODS

A computerized search was used to identify all patients who were diagnosed with aerophagia at the Mayo Clinic, Rochester between 1996 and 2003 (n = 79). Individual medical charts were abstracted for information on the demographics, clinical features, co-morbid diagnoses, diagnostic workup and treatment. Information on presenting symptoms was also collected for a group of patients who were classified as having functional dyspepsia for comparison (n = 121).

RESULTS

The median duration of symptoms in patients with aerophagia was 24 months. The most common symptoms were belching (56%), abdominal pain (19%), bloating (27%) and abdominal distension (19%). Patients with functional dyspepsia had a higher prevalence of reporting nausea, vomiting, early satiety, weight loss and abdominal pain (all P < 0.01, adjusting for age, gender and body mass index). Significantly more patients with aerophagia had anxiety (19%) than those with functional dyspepsia (6%, P < 0.01).

CONCLUSIONS

Individuals with aerophagia experience prolonged upper gastrointestinal symptoms. Initial presenting symptoms appear to be distinctly different from those who have functional dyspepsia.