Fundoplication eliminates chronic cough due to non-acid reflux identified by impedance pH monitoring

GERD-related chronic cough: Possible mechanism, diagnosis and treatment

GERD, or gastroesophageal reflux disease, is a prevalent medical condition that affects millions of individuals throughout the world. Chronic cough is often caused by GERD, and chronic cough caused by GER is defined as GERD-related chronic cough (GERC). It is still unclear what the underlying molecular mechanism behind GERC is. Reflux theory, reflex theory, airway allergies, and the novel mechanism of esophageal motility disorders are all assumed to be linked to GERC. Multichannel intraluminal impedance combined with pH monitoring remains the gold standard for the diagnosis of GERC, but is not well tolerated by patients due to its invasive nature. Recent discoveries of new impedance markers and new techniques (mucosal impedance testing, salivary pepsin, real-time MRI and narrow band imaging) show promises in the diagnosis of GERD, but the role in GERC needs further investigation. Advances in pharmacological treatment include potassium-competitive acid blockers and neuromodulators (such as Baclofen and Gabapentin), prokinetics and herbal medicines, as well as non-pharmacological treatments (such as lifestyle changes and respiratory exercises). More options have been provided for the treatment of GERC other than acid suppression therapy and anti-reflux surgery. In this review, we attempt to review recent advances in GERC mechanism, diagnosis, and subsequent treatment options, so as to provide guidance for management of GERC.

Laryngopharyngeal Reflux Among Patients Undergoing Bariatric Surgery

PURPOSE

The effect of altered subsphincteric gastric volume and pressure after bariatric surgery on laryngopharyngeal reflux (LPR) remains largely unknown. This was a cross-sectional pilot study conducted between January 2018 and January 2019 to identify changes in LPR symptoms and signs in bariatric surgery patients presurgery and postsurgery.

MATERIALS AND METHODS

Thirty-four patients listed for bariatric surgery in a single tertiary referral center were recruited, where 31 (77.4% female, mean age 46.3 ± 8.9 years) fulfilled the eligibility criteria. Of the eligible patients, 54.8% and 45.2% underwent sleeve gastrectomy (SG) and gastric bypass (GB), respectively. LPR symptoms were assessed using the self-reported reflux symptom index (RSI). Video-recorded endolaryngeal signs were scored using the reflux finding score (RFS) by two blinded otolaryngologists. Patients' presurgical and 3-month postsurgical body mass index (BMI), RSI, and RFS were determined. Patients were deemed as having LPR when RSI > 13 or RFS > 7.

RESULTS

There was a significant correlation between the postsurgical RSI and RFS changes (Pearson's r = 0.474, p = 0.007). Of the 31 patients, 12.9% (RSI) and 6.4% (RFS) recovered from preexisting LPR, whereas 22.6% (RSI) and 3.2% (RFS) developed new de novo LPR postsurgery. The postsurgical mean RFS change improved significantly in the GB group compared with that of the SG group (p < 0.05).

CONCLUSION

LPR is best assessed clinically using a multimodal approach (RSI and RFS). Bariatric surgery may worsen or lead to de novo LPR. Recognizing the LPR outcomes in these patients is paramount for optimal voice, speech, and swallowing functions.

Gastroesophageal reflux disease and chronic cough: A possible mechanism elucidated by ambulatory pH-impedance-pressure monitoring

BACKGROUND

The pathophysiological mechanism(s) of gastroesophageal reflux disease (GERD)-related chronic cough (CC) is unclear. We aimed to determine the mechanism of reflux-induced cough by synchronous monitoring of reflux episodes, esophageal motility, and cough.

METHODS

Patients with GERD were prospectively enrolled and classified into GERD with CC (GERD-CC) and without CC (GERD) groups. Twenty-four-hour ambulatory pH-impedance-pressure monitoring was performed; the reflux patterns, esophageal motility during prolonged exposure to acid and characteristics of reflux episodes that induced coughing paroxysms were analyzed.

KEY RESULTS

Thirty-one patients with GERD-CC and 47 with GERD were enrolled; all of whose monitoring results fulfilled the criteria for diagnosis of GERD. Patients with GERD-CC had higher reflux symptom scores, longer exposure to acid, higher DeMeester scores, and more frequent reflux episodes, proximal extent reflux detected by impedance, and higher percentage of strongly acidic reflux than patients in the GERD group (all P < .05). Of 63 reflux-cough episodes identified in the GERD-CC group, 74.6% of distal reflux and 67.0% of proximal reflux episodes were acidic. More patients had low pan-esophageal pressure in primary peristalsis (48.5% vs 11.8%, P = .000) and synchronous contraction in secondary peristalsis during prolonged exposure to acid in the GERD-CC than in the GERD group (63.9% vs 9.1%, P = .000).

CONCLUSIONS & INFERENCES

Proximal acidic reflux and distal reflux-reflex are jointly associated with reflux-induced cough in patients with GERD. Low pan-esophageal pressure in primary peristalsis and synchronous contraction in secondary peristalsis may play important roles in GERD-associated chronic cough.

Clinical measurement of gastrointestinal motility and function: who, when and which test?

Symptoms related to abnormal gastrointestinal motility and function are common. Oropharyngeal and oesophageal dysphagia, heartburn, bloating, abdominal pain and alterations in bowel habits are among the most frequent reasons for seeking medical attention from internists or general practitioners and are also common reasons for referral to gastroenterologists and colorectal surgeons. However, the nonspecific nature of gastrointestinal symptoms, the absence of a definitive diagnosis on routine investigations (such as endoscopy, radiology or blood tests) and the lack of specific treatments make disease management challenging. Advances in technology have driven progress in the understanding of many of these conditions. This Review serves as an introduction to a series of Consensus Statements on the clinical measurements of gastrointestinal motility, function and sensitivity. A structured, evidence-based approach to the initial assessment and empirical treatment of patients presenting with gastrointestinal symptoms is discussed, followed by an outline of the contribution of modern physiological measurement on the management of patients in whom the cause of symptoms has not been identified with other tests. Discussions include the indications for and utility of high-resolution manometry, ambulatory pH-impedance monitoring, gastric emptying studies, breath tests and investigations of anorectal structure and function in day-to-day practice and clinical management.

Extraesophageal Symptoms and Diseases Attributed to GERD: Where is the Pendulum Swinging Now?

The purpose of this review is to outline the recent developments in the field of extraesophageal reflux disease and provide clinically relevant recommendations. The recommendations outlined in this review are based on expert opinion and on relevant publications from PubMed and EMbase. The Clinical Practice Updates Committee of the American Gastroenterological Association proposes the following recommendations: Best Practice Advice 1: The role of a gastroenterologist in patients referred for evaluation of suspected extra esophageal symptom is to assess for gastroesophageal etiologies that could contribute to the presenting symptoms. Best Practice Advice 2: Non-GI evaluations by ENT, pulmonary and/or allergy are essential and often should be performed initially in most patients as the cause of the extraesophageal symptom is commonly multifactorial or not esophageal in origin. Best Practice Advice 3: Empiric therapy with aggressive acid suppression for 6-8 weeks with special focus on response of the extraesophageal symptoms can help in assessing association between reflux and extraesophageal symptoms. Best Practice Advice 4: No single testing methodology exists to definitively identify reflux as the etiology for the suspected extra esophageal symptoms. Best Practice Advice 5: Constellation of patient presentation, diagnostic test results and response to therapy should be employed in the determination of reflux as a possible etiology in extra esophageal symptoms. Best Practice Advice 6: Testing may need to be off or on proton pump inhibitor (PPI) therapy depending on patients' presenting demographics and symptoms in assessing the likelihood of abnormal gastroesophageal reflux. A. On therapy testing may be considered in those with high probability of baseline reflux (those with previous esophagitis, Barrett's esophagus or abnormal pH). B. Off therapy testing may be considered in those with low probability of baseline reflux with the goal of identifying moderate to severe reflux at baseline. Best Practice Advice 7: Lack of response to aggressive acid suppressive therapy combined with normal pH testing off therapy or impedance-pH testing on therapy significantly reduces the likelihood that reflux is a contributing etiology in presenting extraesophageal symptoms. Best Practice Advice 8: Surgical fundoplication is discouraged in those with extra esophageal reflux symptoms unresponsive to aggressive PPI therapy. Best Practice Advice 9: Fundoplication should only be considered in those with a mechanical defect (e.g., hiatal hernia), moderate to severe reflux at baseline off PPI therapy who have continued reflux despite PPI therapy and have failed more conservative non-GI treatments.

Diagnosis and treatment of patients with nonacid gastroesophageal reflux-induced chronic cough

Gastroesophageal reflux (GER) is one of the most common causes of chronic cough, and chronic cough due to GER represents a subtype of GER-related diseases. Gastroesophageal reflux-induced chronic cough (GERC) can be divided into two subgroups based on the pH of the GER. Nonacid GERC is less common than acid GERC, and its diagnosis and treatment strategy have not been standardized. However, nonacid GERC usually presents with its unique set of characteristics and features upon diagnosis and treatment in the clinic. Although the underlying molecular mechanism of nonacid GERC is not fully understood, it is considered to be associated with reflux theory, reflex theory and airway hypersensitivity. Multi-channel intraluminal impedance combined with pH monitoring is a promising new technique that can detect both acid and nonacid reflux, and our findings as well as those of others have shown its usefulness in diagnosing nonacid GERC. Development of new diagnostic techniques has led to an increased rate of nonacid GERC diagnosis. We summarize our experience in the diagnosis and treatment of nonacid GERC and provide a guide for future therapeutic approaches.

Chronic dry cough: Diagnostic and management approaches

Cough is the most common symptom for which medical treatment is sought in the outpatient setting. Chronic dry cough poses a great diagnostic and management challenge due to myriad etiologies. Chronic cough has been commonly considered to be caused by gastroesophageal reflux, post-nasal drip or asthma. However, recent evidences suggest that many patients with these conditions do not have cough, and in those with cough, the response to specific treatments is unpredictable at best. This raises questions about the concept of a triad of treatable causes for chronic cough. This article discusses the mechanism and etiology of cough, along with recent advances in the field of cough, highlighting some of the diagnostic and management challenges.

The utility of endoscopy and multichannel intraluminal impedance testing in children with cough and wheezing

BACKGROUND

Gastroesophageal reflux (GER) has been implicated as a causal factor in respiratory disease but prior studies have focused on the role of acid alone in the genesis of symptoms. Prior studies have relied on pH probe testing but this is blind to non-acid reflux which has been implicated in the genesis of extraesophageal symptoms. The objective of this prospective, cross-sectional study is to determine the utility of gastroesophageal reflux testing, including multichannel intraluminal impedance with pH (pH-MII) and upper gastrointestinal endoscopy (EGD), in the child with intractable cough and wheezing. We hypothesize that there is a high rate of pathologic reflux testing in these patients.

METHODS

Children ages 1-18 with chronic cough and wheezing who were undergoing bronchoscopy for the evaluation of cough and wheezing were recruited into this prospective, cross-sectional study. They underwent identical reflux testing with pH-MII and EGD at the time of bronchoscopy. Reflux burden, symptom association, and rates of esophageal pathology were determined. Results 58% of patients had abnormal reflux testing; 67% of patients had an abnormal pH-MII test and 32% of patients had abnormal esophageal biopsies. The most common pH-MII abnormality was an abnormal symptom association between cough and reflux and the most common endoscopic abnormality was reflux esophagitis. Seven percent of patients presenting only with cough were diagnosed with eosinophilic esophagitis.

CONCLUSIONS

There is a high yield to reflux testing in children with chronic cough and wheezing.

Chronic cough: an otorhinolaryngology perspective

PURPOSE OF REVIEW

Cough lasting more than 8 weeks is a common presenting complaint to the otolaryngologist. Historically, chronic cough has been attributed to post-nasal drip, laryngopharyngeal reflux and cough-variant asthma. This study reviews chronic cough from the viewpoint of an otolaryngologist.

RECENT FINDINGS

More recent studies suggest the influence of laryngeal neuropathy and its interplay with laryngopharyngeal reflux. There is limited evidence for post-nasal drip or cough-variant asthma causing chronic cough.

SUMMARY

In this study, we review the evidence for cause of chronic cough, as well as up to date techniques for the otolaryngologist, including transnasal esophagoscopy, to assess the patient in clinic allowing accurate diagnosis. Treatment options for the otolaryngologist are discussed and the role of multidisciplinary input emphasized.

Intraesophageal pressure recording improves the detection of cough during multichannel intraluminal impedance testing in children

BACKGROUND

One of the primary reasons for referral for reflux testing is to correlate reflux events with symptoms such as cough. Adult studies have suggested that symptom recording is flawed and pediatricians feel this is an even more significant problem because there may be errors in both parental and patient reports. We hypothesize that intraesophageal pressure recording (IEPR) provides an objective method to identify coughs during reflux testing in children.

METHODS

We recruited 20 children undergoing multichannel intraluminal impedance with pH (pH-MII) testing for the evaluation of cough. We placed simultaneous intraesophageal pressure and pH-MII catheters. Tracings were blindly scored by 2 observers without knowledge of patient/parent symptom report. After the blinded scoring, patient/parent report of symptoms was recorded.

RESULTS

Ninety-four percent of all coughs were detected by IEPR and only 48% of all coughs were reported by patients/parents. The mean time from the IEPR cough to the patient/parent cough was 11±16 seconds. Using IEPR as the criterion standard for the detection of cough, the sensitivity of patient report for the detection of cough is 46%. Using varying symptom windows because of the increased precision of IEPR, the number of patients with a positive symptom index could be reduced from 30% to 0%, preventing children from being falsely categorized as having reflux-related lung disease.

CONCLUSIONS

Parental and patient symptom recording in children is inadequate for making the diagnosis of reflux-related lung disease. If patients undergo pH-MII testing for reflux-related cough, IEPR should become the new standard by which to correlate reflux with cough.

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.

Findings of impedance pH-monitoring in patients with atypical gastroesophageal reflux symptoms

AIM

This study was designed to investigate about findings of Impedance pH-monitoring in patients with atypical symptoms of GERD.

BACKGROUND

The routine treatment with proton pump inhibitors is not very effective in patients with atypical symptoms of Gastro-Esophageal Reflux Disease (GERD). It may be due to non-acid reflux which cannot be monitored using common methods such as pH-metry. Therefore, in these patients combinational procedure of multi channel intraluminal impedance and pH monitoring has been suggested as a new approach.

PATIENTS AND METHODS

Sixty patients with atypical symptoms of GERD underwent combined impedance pH-monitoring. pH of reflux episodes, type of material refluxant, blous cleaning time, proximal extension and symptoms association probability (SAP) was recorded for each patient.

RESULTS

Globus sensation was reported as the most common atypical symptom. 95% of patients experienced weakly acid reflux. Mixed and pure gas refluxates were more frequent than pure liquid reflux. Bolus clearing time was pathologic in 36.7% of cases and proximal extension was detected in 43 patients (71.7%). Of the 46 symptomatic patients, 33.3% had a positive SAP and 43.3% had a negative SAP.

CONCLUSION

The findings of current study showed that the combinational procedure of MII and pH monitoring could provide important information for resistant to treatment patients' with atypical GERD symptoms.

How many cases of laryngopharyngeal reflux suspected by laryngoscopy are gastroesophageal reflux disease-related?

AIM: To investigate the prevalence of gastroesophageal reflux disease (GERD) in patients with a laryngoscopic diagnosis of laryngopharyngeal reflux (LPR).

METHODS: Between May 2011 and October 2011, 41 consecutive patients with laryngopharyngeal symptoms (LPS) and laryngoscopic diagnosis of LPR were empirically treated with proton pump inhibitors (PPIs) for at least 8 wk, and the therapeutic outcome was assessed through validated questionnaires (GERD impact scale, GIS; visual analogue scale, VAS). LPR diagnosis was performed by ear, nose and throat specialists using the reflux finding score (RFS) and reflux symptom index (RSI). After a 16-d wash-out from PPIs, all patients underwent an upper endoscopy, stationary esophageal manometry, 24-h multichannel intraluminal impedance and pH (MII-pH) esophageal monitoring. A positive correlation between LPR diagnosis and GERD was supposed based on the presence of esophagitis (ERD), pathological acid exposure time (AET) in the absence of esophageal erosions (NERD), and a positive correlation between symptoms and refluxes (hypersensitive esophagus, HE).

RESULTS: The male/female ratio was 0.52 (14/27), the mean age ± SD was 51.5 ± 12.7 years, and the mean body mass index was 25.7 ± 3.4 kg/m². All subjects reported one or more LPS. Twenty-five out of 41 patients also had typical GERD symptoms (heartburn and/or regurgitation). The most frequent laryngoscopic findings were posterior laryngeal hyperemia (38/41), linear indentation in the medial edge of the vocal fold (31/41), vocal fold nodules (6/41) and diffuse infraglottic oedema (25/41). The GIS analysis showed that 10/41 patients reported symptom relief with PPI therapy (P < 0.05); conversely, 23/41 did not report any clinical improvement. At the same time, the VAS analysis showed a significant reduction in typical GERD symptoms after PPI therapy (P < 0.001). A significant reduction in LPS symptoms. On the other hand, such result was not recorded for LPS. Esophagitis was detected in 2/41 patients, and ineffective esophageal motility was found in 3/41 patients. The MII-pH analysis showed an abnormal AET in 5/41 patients (2 ERD and 3 NERD); 11/41 patients had a normal AET and a positive association between symptoms and refluxes (HE), and 25/41 patients had a normal AET and a negative association between symptoms and refluxes (no GERD patients). It is noteworthy that HE patients had a positive association with typical GERD-related symptoms. Gas refluxes were found more frequently in patients with globus (29.7 ± 3.6) and hoarseness (21.5 ± 7.4) than in patients with heartburn or regurgitation (7.8 ± 6.2). Gas refluxes were positively associated with extra-esophageal symptoms (P < 0.05). Overall, no differences were found among the three groups of patients in terms of the frequency of laryngeal signs. The proximal reflux was abnormal in patients with ERD/NERD only. The differences observed by means of MII-pH analysis among the three subgroups of patients (ERD/NERD, HE, no GERD) were not demonstrated with the RSI and RFS. Moreover, only the number of gas refluxes was found to have a significant association with the RFS (P = 0.028 and P = 0.026, nominal and numerical correlation, respectively).

CONCLUSION: MII-pH analysis confirmed GERD diagnosis in less than 40% of patients with previous diagnosis of LPR, most likely because of the low specificity of the laryngoscopic findings.

Fundoplication in chronic intractable cough

Background

Airway reflux is a common cause of chronic cough and this is often refractory to medical therapy. Surgery in the form of Nissen fundoplication has been highly successful in the treatment of the classic reflux symptoms of heartburn and dyspepsia. There is a paucity of data regarding response to fundoplication in patients presenting with chronic cough.

Methods

We retrospectively reviewed the case notes of patients from the Hull Cough Clinic who had undergone Nissen fundoplication over the past 6 years. Demographic details, duration of symptoms, presence of other symptoms, results of oesophageal studies, outcome and complications were recorded. Patients were contacted by post and asked to complete a questionnaire detailing current symptoms. In a subgroup with continued troublesome cough 24 hour pharyngeal pH measurements were undertaken.

Results

Forty seven patients underwent fundoplication. The average duration of pre-operative cough was 8 years. Gastro intestinal symptoms were present in the majority. In 30 (64%) patients a positive response to treatment was recorded. Mild dysphagia or bloating was seen in 18 patients following surgery. Four patients needed repeat surgical intervention for modification of fundoplication. One patient developed aspiration pneumonia eight weeks following surgery and died of a myocardial infarction. Two thirds of patients with persisting cough had evidence of airway reflux on pharyngeal pH monitoring.

Conclusion

In these patients with intractable cough a long term response rate of 63% represents a useful therapeutic option. Treatment failure is more frequent than for classic peptic symptoms and may be related to persistent gaseous reflux.

The impact of reflux burden on Pseudomonas positivity in children with cystic fibrosis

OBJECTIVES

Nonacid gastroesophageal reflux (GER), particularly in patients taking acid suppression, has been implicated as a cause of respiratory infections. We hypothesize that children with cystic fibrosis (CF) and a higher nonacid reflux burden have greater rates of Pseudomonas aeruginosa (Pa) infection than patients with a lower reflux burden.

STUDY DESIGN

We reviewed the multichannel intraluminal impedance (pH-MII) tracings of 35 patients with CF between 2003 and 2010. We compared the reflux profiles between those patients who were Pa positive and Pa negative.

RESULTS

The mean age was 13.5 ± 5.8 years. Twenty-seven patients (76%) were Pa positive. Ninety seven percent of patients were taking proton pump inhibitors during pH-MII testing. The mean percentage of time pH was <4 was 8.5 ± 12%. Pa patients had a significantly higher total, acid and proximal nonacid reflux burden (P < 0.009). There was a negative correlation between nonacid reflux burden and FEV1 (r = -0.397, P = 0.03) and between total number of reflux events and FEV1 (r = -0.474, P = 0.009). After adjusting for age and FEV1, total reflux burden remains significantly associated with Pa positivity (P = 0.055).

CONCLUSIONS

Increased reflux burden may predispose patients to Pa infection and worse lung function.

Differential diagnosis in allergy

The otolaryngic allergist must be able to distinguish between common nonallergic diagnoses that present very similarly to allergic conditions. This article describes a few of the vast myriad of conditions that must be ruled out before a diagnosis of allergy may be made. After reading this article clinicians will be able to identify various conditions, which will enhance their ability to appropriately make correct decisions for prompt and efficient management of their patients with allergic or nonallergic diseases of the head and neck.

Does reflux monitoring with multichannel intraluminal impedance change clinical decision making?

OBJECTIVES

Multichannel intraluminal impedance with pH (pH-MII) has become the criterion standard test for the evaluation of gastroesophageal reflux disease, but it is not clear whether the results of this test change clinical decision making. The goal of the present study was to determine the differences in clinical decision making by attending physicians based on the pH probe results versus MII results.

METHODS

We conducted a prospective study in which physicians were initially given pH probe results and asked how they would change the patient's clinical management based on these results. Physicians were then given the MII results and asked how their management would change. Physicians then were asked whether they believed MII affected their clinical decision making overall.

RESULTS

pH probe results changed clinical management 40% of the time and MII results changed clinical management an additional 22% of the time. Clinical decision making was not influenced by the performance of pH-MII on or off acid suppression. The escalation of acid suppression therapy was the main management change that occurred based on the pH-MII results.

CONCLUSIONS

The addition of MII to the standard pH probe resulted in a change in management in approximately 25% of the patients, suggesting that there may be a role for pH-MII in clinical practice.

Effect of different pH criteria on dual-sensor pH monitoring in the evaluation of supraesophageal gastric reflux in children

BACKGROUND AND AIM

Existing tests for supraesophageal gastric reflux (SEGR) that focus on pH drops <4 in the proximal esophagus have had limited sensitivity and specificity. The aim of the present study was to evaluate the effect of newly proposed pH criteria on SEGR detection.

PATIENTS AND METHODS

Twenty-four-hour dual-sensor pH tracings of 32 patients were reviewed. Proximal esophageal pH data were evaluated according to the conventional definition of pH drop <4 and 2 proposed definitions: pH drop <5.5 while upright and <5.0 while supine and pH drop of >10% from a running baseline. For each potential SEGR event, the preceding 1-minute window was examined for corresponding distal acid reflux.

RESULTS

Of the 542 distal acid reflux events detected, 200 were associated with a proximal pH drop <4; this number increased to 295 using the definition of proximal pH drop <5.5 (upright)/<5.0 (supine) and 301 using the definition of proximal pH drop >10%. A proportion of proximal events, however, was not associated with distal acid reflux: 21 of 200 (10.5%) proximal pH <4 events, 119 of 414 (29%) proximal pH <5.5 (upright)/<5.0 (supine) events, and 272 of 573 (47%) proximal pH drop >10% events lacked a preceding or simultaneous drop in distal pH <4.

CONCLUSIONS

Although the use of more liberal pH criteria increased the diagnostic yield for SEGR events with dual-sensor monitoring, a significant proportion of proximal pH events did not correlate with distal acid reflux. These events could represent either false-positive measurements or association with weakly acid reflux.

Acoustic cough-reflux associations in chronic cough: potential triggers and mechanisms

BACKGROUND & AIMS

Central sensitization is thought to play a role in chronic cough and might explain the temporal association between cough and gastroesophageal reflux (GOR) in patients in whom non-GOR causes have been excluded. Using our novel simultaneous acoustic cough recording and impedance/pH monitoring technique, we aimed to explore this further by assessing such temporal associations and their relationship to the acidity, duration, and proximal extent of reflux and the presence of erosive disease and cough reflex sensitivity in unselected patients (ie, including non-GOR causes) with chronic cough.

METHODS

Twenty-four hour ambulatory acoustic cough monitoring with simultaneous impedance/pH recording was carried out in 71 unselected patients with chronic cough, aged 51-64 years (47 female). In addition, all patients underwent cough reflex sensitivity testing to citric acid, and 66 patients underwent gastroscopy. Temporal associations between cough and reflux were expressed using the symptom association probability.

RESULTS

Seventy percent of patients exhibited temporal associations, with 48% having a positive symptom association probability (SAP(R-C)) for cough preceded by reflux (mainly distal), 56% a positive symptom association probability (SAP(C-R (2 min))) for reflux preceded by cough, and 32% both. Moreover, SAP(R-C) positive patients had a more sensitive cough reflex (P = .03) but similar esophageal reflux exposure and erosive disease, together with similar prevalence of extraesophageal causes of cough compared with SAP(R-C) negative patients. Reflux immediately following cough was rare.

CONCLUSIONS

Cough temporally associates with reflux irrespective of proposed diagnoses, may be self-perpetuating in some patients, and is likely to be driven by central processes.

Future directions in treating cough

Cough is a common and troublesome symptom that can be difficult to treat. New therapeutic options that are safe and more effective than those currently available are needed. In this article, the authors offer opinion on future directions in the treatment of cough, with a particular emphasis on the clinical syndrome associated with cough reflex hypersensitivity. In addition, the article provides an overview of some of the diagnostic technologies and promising drug targets likely to emerge from current clinical and scientific endeavor.

Reflux events detected by pH-MII do not determine fundoplication outcome

BACKGROUND

Because of complications and its invasive nature, fundoplication is often a treatment of last resort for children with gastroesophageal reflux. Gastroesophageal reflux testing does not always predict who will benefit from antireflux surgery. Furthermore, there are no studies to determine whether a higher preoperative reflux burden, including acid and nonacid reflux, is associated with an improved postfundoplication outcome. The aim of the study was to determine predictors of fundoplication outcome including acid and nonacid reflux burden.

PATIENTS AND METHODS

We retrospectively reviewed preoperative pH-multichannel intraluminal impedance tracings and medical records of 34 patients who underwent fundoplication. Patients were categorized as improved or not improved, and the demographic and reflux characteristics were compared between groups. Multivariate analysis was performed to determine predictors of outcome.

RESULTS

No single reflux marker, including the number of acid, nonacid, total events, or the percentage of time that reflux was in the esophagus, predicted fundoplication outcome (P > 0.1). Neither a positive symptom index nor a positive symptom sensitivity index predicted postoperative improvement (P > 0.4). Receiver operating characteristic curve analysis failed to reveal an ideal value to maximize sensitivity for either the symptom index or the symptom sensitivity index.

CONCLUSIONS

pH-multichannel intraluminal impedance testing may not be a useful tool in predicting fundoplication outcome.

New insights in cough

Chronic cough is common, blights patients' lives and is hard to treat. Chronic cough patients demonstrate high objective cough rates and as a group have increased cough reflex sensitivity. However, conventional cough challenge techniques show substantial overlap with normal subjects. This suggests that other important mechanisms have yet to be determined. For the last two decades, chronic cough has been considered to be caused by gastro-oesophageal reflux, post-nasal drip or asthma. However, many patients with these conditions do not have cough, and in those with cough, the response to specific treatments is unpredictable at best. In addition, many chronic cough patients do not have an identifiable cause. This raises questions about the concept of a triad of treatable causes for chronic cough. Our current understanding of the neurophysiology of the cough reflex is largely derived from animal work with limited data in humans. By analogy with chronic pain syndromes, both peripheral and central sensitization may be important mechanisms in chronic cough, and are under active investigation. We need to understand the mechanisms underlying sensitization, how they interact with cough triggers and their relationship with the sensations that drive the urge to cough, and the subsequent motor cough response in chronic cough. Only then will we develop effective interventions.

Azithromycin reduces gastroesophageal reflux and aspiration in lung transplant recipients

Azithromycin (AZI) is a macrolide antibiotic that improves lung function in lung transplant recipients (LTx). Gastroesophageal reflux (GER) has been implicated in the pathogenesis of chronic rejection after LTx. Macrolide antibiotics may affect GER by modifying esophageal and gastric motility. The purpose of this study was to evaluate the effect of AZI on GER and gastric aspiration after LTx. Acid and weakly acidic GER was measured with 24-h pH-impedance monitoring in 47 LTx patients (12 patients "on" AZI). Gastric aspiration was assessed in a separate group of 30 LTx patients before and after AZI by measurements of pepsin and bile acid in bronchoalveolar lavage fluid (BALF). Patients "on" AZI had a significant lower total number of reflux events [41 (30-61) vs. 22.5 (7-37.5)], number of acid reflux events [24 (16-41) vs. 8 (4-18)], esophageal acid exposure [2.9% (0.7-7.3) vs. 0.2% (0.1-2.0)], bolus exposure [0.73% (0.5-1.4) vs. 0.21% (0.12-0.92)], and proximal extent of reflux [14 (9-24) vs. 5 (2-7)]. AZI reduced the concentration of bile acids in BALF without affecting levels of pepsin. LTx patients "on" AZI have less GER and bile acids aspiration. This effect might be due to enhanced esophageal motility and accelerated gastric emptying.

Cough in adult cystic fibrosis: diagnosis and response to fundoplication

BACKGROUND

Gastroesophageal reflux is one of the most common causes of chronic cough in the general population. Reflux occurs frequently in patients with cystic fibrosis (CF). We undertook laparoscopic Nissen fundoplication in adult CF patients with a clinical diagnosis of reflux cough who had failed conventional medical therapies.

OBJECTIVE

We determined the response to the surgical route in the treatment of intractable reflux cough in CF.

METHOD

Patients with refractory cough were assessed by 24 h pH monitoring and oesophageal manometry. Pre-and post-operation cough, lung function and exacerbation frequency were compared. Cough was assessed by the Leicester Cough Questionnaire (LCQ), lung function by spirometry and exacerbation frequency was defined by comparing the postoperative epoch with a similar preoperatively.

RESULTS

Significant abnormalities of oesophageal function were seen in all patients studied. 6 patients (2 females), with the mean age of 34.5 years consented to surgery. Their mean number of reflux episodes was 144.4, mean DeMeester score was 39.2, and mean lower oesophageal sphincter pressure 12.4 mmHg. There was a small change in the FEV1 from 1.03 L to 1.17 (P = 0.04), and FVC improved from 2.62 to 2.87 (P = 0.05). Fundoplication lead to a marked fall in cough with the total LCQ score increasing from 11.9 to 18.3 (P = 0.01). Exacerbation events were reduced by 50% post operatively.

CONCLUSION

Whilst there is an obvious attention to respiratory causes of cough in CF, reflux is also a common cause. Fundoplication is highly effective in the control of reflux cough in CF. Significant reduction in exacerbation frequency may indicate that reflux with possible aspiration is a major unrecognised contributor to airway disease.

Gastroesophageal reflux monitoring: pH (catheter and capsule) and impedance

Diagnostic testing for GERD has evolved to include multi esophageal sites (distal, proximal and hypopharyngeal monitoring), wireless pH, and oropharyngeal devices. The versatility of the devices has increased our ability to better understand the role of acid reflux in various disorders involving reflux of acid. Wireless pH monitoring improves patient comfort and allows monitoring for gastroesophageal reflux events over several days. Ambulatory MII-pH monitoring is another exciting diagnostic tool, which is capable of detecting more than one type of reflux and achieves higher sensitivity and specificity to detect GERD than endoscopy or pH-metry. It is useful in patients with either typical or atypical reflux symptoms who are refractory to proton pump inhibitor (PPI) therapy. In this setting, MII-pH can be performed on PPI therapy to assess the efficacy of PPIs and the role of nonacid or acid reflux in persistent symptoms.

Ambulatory monitoring of GERD: current technology

Various techniques have been devised to diagnose, characterize, and classify gastroesophageal reflux (GER). Stationary techniques, such as fluoroscopy and scintigraphy, provide interesting anatomic and functional information related to GER but are not sensitive enough and are usually performed in nonphysiologic conditions. Ambulatory techniques for GER monitoring have been developed and used since 1974. The current available techniques include catheter and wireless pH-metry, Bilitec, and impedance-pH monitoring. Prolonged wireless pH monitoring can be useful to evaluate patients off and on proton pump inhibitor (PPI) treatment. Impedance-pH monitoring is being used increasingly in patients who have persistent symptoms on PPI therapy because it can establish an association between symptoms and weakly acidic or nonacid reflux. Bilitec is performed in patients suspected to have increased duodenogastroesophageal reflux (DGER). This article discusses the technical details, clinical indications, and applications of these diagnostic techniques.

High-resolution manometry and impedance-pH/manometry: valuable tools in clinical and investigational esophagology

Both high-resolution manometry (HRM) and impedance-pH/manometry monitoring have established themselves as research tools and both are now emerging in the clinical arena. Solid-state HRM capable of simultaneously monitoring the entire pressure profile from the pharynx to the stomach along with pressure topography plotting represents an evolution in esophageal manometry. Two strengths of HRM with pressure topography plots compared with conventional manometric recordings are (1) accurately delineating and tracking the movement of functionally defined contractile elements of the esophagus and its sphincters, and (2) easily distinguishing between luminal pressurization attributable to spastic contractions and that resultant from a trapped bolus in a dysfunctional esophagus. Making these distinctions objectifies the identification of achalasia, distal esophageal spasm, functional obstruction, and subtypes thereof. Ambulatory intraluminal impedance pH monitoring has opened our eyes to the trafficking of much more than acid reflux through the esophageal lumen. It is clear that acid reflux as identified by a conventional pH electrode represents only a subset of reflux events with many more reflux episodes being composed of less acidic and gaseous mixtures. This has prompted many investigations into the genesis of refractory reflux symptoms. However, with both technologies, the challenge has been to make sense of the vastly expanded datasets. At the very least, HRM is a major technological tweak on conventional manometry, and impedance pH monitoring yields information above and beyond that gained from conventional pH monitoring studies. Ultimately, however, both technologies will be strengthened as outcome studies evaluating their utilization become available.

Non-acidic supraesophageal reflux associated with diffuse alveolar damage and allograft dysfunction after lung transplantation: a case report

Advances in lung transplantation have improved 1-year survival rates, but allograft dysfunction continues to be a significant cause of post-transplant death. Diffuse alveolar damage is an early indication of allograft dysfunction and has been linked to gastroesophageal reflux. We report a case of diffuse alveolar damage-associated allograft dysfunction in a patient found to have significant non-acid gastroesophageal reflux.

An analysis of persistent symptoms in acid-suppressed patients undergoing impedance-pH monitoring

BACKGROUND & AIMS

Despite proton-pump inhibitors (PPIs), patients may have persistent symptoms of gastroesophageal reflux disease (GERD). We aimed to identify symptom types and frequency experienced by patients on PPI therapy, and to identify the type of reflux, if any, associated with these symptoms.

METHODS

A retrospective review was performed of 200 patients on PPI with GERD symptoms during ambulatory impedance-pH testing. The symptom index (SI) was determined for each symptom, and an SI of 50% or more was considered positive. Patients were divided into 2 groups: those with exclusively nonacid reflux (NAR) episodes and those with mixed-acid and NAR episodes. Symptom profiles were compared between these 2 groups.

RESULTS

A total of 415 symptoms were reported by the 200 patients on twice-daily PPIs. Throat clearing was most common (24%). A total of 110 (27%) were typical symptoms and 305 (73%) were atypical. Typical symptoms were more likely to have a positive SI than atypical symptoms (48% vs 25%, P < .01). Eighty-four patients (42%) had a positive SI, and 116 patients (58%) had a negative SI. One hundred patients (50%) had only NAR; the other 100 had mixed acid and NAR. Heartburn (21% vs 63%, P < .01) and nausea (8% vs 44%, P < .01) were more likely associated with reflux in the mixed-acid and NAR group.

CONCLUSIONS

Patients on PPIs still experience GERD symptoms. Impedance-pH monitoring identifies similar symptom associations with all types of reflux and also clarifies symptoms not related to any reflux.

Lipid-laden macrophage index is not an indicator of gastroesophageal reflux-related respiratory disease in children

BACKGROUND

The lipid-laden macrophage index has been used to evaluate for gastroesophageal reflux-related respiratory disease, but the relationship between reflux detected by pH probe and the lipid-laden macrophage index is uncertain despite widespread use of the lipid-laden macrophage index in clinical decision-making. It was the aim of this study to correlate reflux as detected by multichannel intraluminal impedance with the lipid-laden macrophage index.

METHODS

Patients undergoing both pH multichannel intraluminal impedance testing and bronchoscopy between January 2002 and January 2006 were identified. Baseline characteristics were compared by using parametric and nonparametric testing. Reflux profiles were correlated with the lipid-laden macrophage index by using Spearman correlations.

RESULTS

There was no significant correlation between the lipid-laden macrophage index and the number of acid or nonacid reflux events. There also was no significant correlation between the lipid-laden macrophage index and the amount of full-column reflux. There was no significant difference between the mean lipid-laden macrophage index in patients with and without esophagitis. Finally, in patients who underwent fundoplication (n = 13) for intractable respiratory disease, there was no significant difference in any of the reflux parameters between patients who did and did not experience clinical improvement after fundoplication. There was, however, a higher lipid-laden macrophage index in patients with no symptomatic improvement compared with patients with symptomatic improvement.

CONCLUSIONS

Lipid-laden macrophage index lacks the specificity necessary to detect reflux-related respiratory disease.

Esophageal impedance-pH monitoring

Classical techniques like endoscopy and esophageal pH-metry are routinely used to study patients with symptoms related to gastroesophageal reflux disease (GERD). Although these techniques have been useful over the years both for diagnosis and therapeutic guidance, there are still many patients with typical or atypical GERD symptoms with normal endoscopy and pH-metry that do not respond adequately to antisecretory therapy. Ambulatory esophageal impedance-pH monitoring is a new technique that can be used to evaluate all types of gastroesophageal reflux, achieving higher rates of sensitivity and specificity than standard techniques. This review describes esophageal impedance-pH monitoring, summarizing the current literature on validation studies and clinical application.

New technologies to evaluate esophageal function

This review provides an overview of the recent advances made in diagnostic technologies of esophageal functional disorders. There is discussion of technologies that evaluate esophageal motor function with special attention to high-resolution manometry and esophageal manometry combined with intraluminal impedance testing. Technologies to evaluate gastroesophageal reflux disease are presented with focus on 24-h ambulatory pH monitoring with intraluminal impedance testing and 48-h ambulatory catheter-free pH monitoring. These new technologies have advanced the study and treatment of esophageal disorders in that they allow for more accurate diagnosis of known esophageal disorders and have introduced previously unexplored disorders, such as achalasia with shortening of the esophagus and nonacid reflux.

Improved diagnosis of gastro-oesophageal reflux in patients with unexplained chronic cough

BACKGROUND

Symptoms, oesophageal pHmetry and proton pump inhibitor treatment are used for diagnosing gastro-oesophageal reflux-related cough. Weakly acidic reflux is now increasingly associated with reflux symptoms such as regurgitation or chest pain.

AIM

To study the association between weakly acidic reflux and cough in a selected, large group of patients with unexplained chronic cough.

METHODS

A total of 100 patients with chronic cough (77 'off' and 23 'on' a proton pump inhibitor) were studied using impedance-pHmetry for reflux detection and manometry for objective cough monitoring. Symptom Association Probability (SAP) Analysis characterized the reflux-cough association.

RESULTS

Acid reflux could be a potential mechanism for cough in 45 patients (with either heartburn, high acid exposure or +SAP for acid reflux). Weakly acidic reflux could be a potential mechanism for cough in 24 patients (with either increased oesophageal volume exposure, increased number of weakly acidic reflux or +SAP for weakly acidic reflux). Reflux could not be identified as a potential mechanism for cough in 31 patients.

CONCLUSION

A positive association between cough and weakly acidic reflux was found in a significant subgroup of patients with unexplained chronic cough. Impedance-pH-manometry identified patients in whom cough can be related to reflux that would have been disregarded using the standard diagnostic criteria for acid reflux.

Nonacid reflux in patients with chronic cough on acid-suppressive therapy

BACKGROUND

It is generally accepted that extraesophageal gastroesophageal reflux disease (GERD) symptoms and their persistence despite acid-suppressive therapy are poor prognostic factors for antireflux surgery. Recent studies indicating that cough can be temporally associated with reflux episodes of pH 4 to 7 (ie, nonacid reflux) reinvigorates the need for a more careful workup in patients with cough suspected to be due to GERD.

AIM

To evaluate the frequency of chronic cough associated with nonacid reflux and the response of these patients to laparoscopic Nissen fundoplication.

METHODS

We retrospectively reviewed data from patients with persistent cough despite twice-daily proton pump inhibitor (PPI) with or without the use of nighttime regimens of histamine-2 receptor antagonist (H2RA), who had undergone combined multichannel intraluminal impedance and pH monitoring. The association of cough and reflux was evaluated by calculating the symptom index (SI) [positive if > or = 50%]. A subset of patients with positive SI values for impedance-detected reflux with therapy was referred for laparoscopic Nissen fundoplication.

RESULTS

Of 50 patients (38 female patients; mean age, 43 years; age range, 6 months to 84 years) who were monitored while receiving therapy, 13 patients (26%) had a positive SI for cough. The SI-positive group had a lower percentage of female patients and patients of younger age compared to the SI-negative group. Laparoscopic Nissen fundoplication was performed in six SI-positive patients who became asymptomatic and stopped receiving acid-suppressive therapy during follow-up evaluations (median time, 17 months; range, 12 to 27 months).

CONCLUSION

Impedance pH monitoring should be performed while receiving therapy in patients with persistent symptoms who are receiving PPI therapy. A positive SI for nonacid reflux may be helpful in selecting patients who will benefit from antireflux surgery.

Clinical cough and its mechanisms

Cough is the commonest symptom of clinical importance and the most frequent reason for new consultations with a doctor. Although therapy directed at any underlying cause for cough can be effective there is a clinical need for new treatments specifically directed at the cough itself. A major obstacle to the development of such therapy has been an imprecise understanding of the pathophysiological mechanisms responsible for cough. In this article, we review the important clinical aspects of both acute and chronic cough, offer practical insight into the existing treatment options, highlight the current understanding of cough pathophysiology and identify important areas for future research effort.

Technology Insight: the role of impedance testing for esophageal disorders

Classic techniques like videofluoroscopy, stationary manometry, and ambulatory 24 h pH-metry are routinely used in the clinic to study patients with dysphagia, chest pain and reflux-related symptoms. Although these techniques have been very useful over the years, both for diagnosis and for therapeutic guidance, there are still many patients with dysphagia or chest pain who remain undiagnosed even after testing, and patients with typical and atypical symptoms of gastroesophageal reflux disease, with normal pH-metry findings, who do not respond adequately to antisecretory therapy. Esophageal impedance monitoring is a new technique that can be used alone and in combination with pH-metry and manometry to evaluate bolus transport and all types of gastroesophageal reflux (acid and nonacid). This review describes the esophageal impedance monitoring technique and summarizes the published validation studies that compare impedance monitoring with other methods, as well as normal values and reproducibility of impedance patterns and their association with symptoms.