Combined ambulatory esophageal manometry and dual-probe pH-metry in evaluation of patients with chronic unexplained cough

Positive bronchoalveolar lavage pepsin assay associated with viral and fungal respiratory infections in children with chronic cough

OBJECTIVE

To assess the association between commonly obtained endoscopic and serologic data and bronchoalveolar lavage pepsin assay (BAL) results in children with chronic cough.

STUDY DESIGN

We performed a retrospective chart review of 72 children with a BAL pepsin obtained through our Aerodigestive Center over an 18-month period. BAL outcomes include evidence of viral, bacterial, or fungal infection, presence of lipid-laden macrophages, and cytology (eosinophils, neutrophils, and lymphocytes). Gastrointestinal outcomes include esophagogastroduodenoscopy (EGD) and pH impedance probe findings. Other characteristics include serum eosinophils, neutrophils, and lymphocytes; spirometry; FeNO; and IgE.

RESULTS

Seventy-two patients underwent BAL pepsin testing. Median age was 4.9 years, 30.6% had severe persistent asthma, and 59.2% were on reflux medication. There was an association between positive BAL pepsin assay and positive viral panel (p = .002) or fungal culture (p = .027). No significant association found between positive BAL bacterial culture; BAL cytology; the presence of BAL lipid-laden macrophages; IgE; spirometry; FeNO; CBC neutrophil, eosinophil, or lymphocytes; pH impedance testing parameters; or EGD pathology.

CONCLUSIONS

BAL pepsin is associated with a positive BAL viral PCR or fungal culture. Lack of correlation between pepsin-positivity and pH-impedance parameters or EGD pathology suggests microaspiration may be due to an acute event (such as a respiratory infection) rather than chronic gastroesophageal reflux disease. This may be especially true in the presence of a positive viral panel or fungal culture when a BAL pepsin is obtained.

Life-Threatening and Non-Life-Threatening Complications Associated With Coughing: A Scoping Review

BACKGROUND

This is an update of the section on complications that are associated with coughing in the 2006 CHEST cough guidelines that addresses two aims: (1) to systematically identify and thematically categorize the diverse complications of cough by providing a guide for future studies and (2) to identify gaps in the literature for future research.

RESEARCH QUESTION

What are the potential complications that are associated with the act of coughing that have been reported in infants, children, adolescents, and adults?

STUDY DESIGN AND METHODS

A scoping review was performed with the use of PubMed and SCOPUS databases that were searched from their beginning until September 6, 2019.

RESULTS

Two hundred forty-seven publications met our inclusion criteria. To these, we added 38 articles from the 2006 complications paper that were not identified in the literature search plus the paper itself for a final total of 286 publications that formed the basis of this review. Since 2006, three new categories of complications have been reported: ear, nose and throat; disease transmission; and laboratory testing. Multiple additional complications that fall outside of these three categories have also been identified and included in the following categories: cardiovascular, constitutional symptoms, dermatologic, GI, genitourinary, musculoskeletal, neurologic, ophthalmologic, psychosocial/quality of life, and respiratory. Not previously highlighted is that some of the complications led to serious morbidity that included death, especially in patients with comorbid conditions, and potentially resulted in harm to others when cough resulted in a motor vehicle accident.

INTERPRETATION

Our work identified a large number of cough complications that we thematically categorized primarily by organ system so that future studies of each system or each complication can be conducted. The gap in the literature that future studies should address is to identify the frequency of the complications and the strength of their association with cough. Only then will one be able to describe the findings in a manner that allows specific recommendations for avoiding these complications. In the meantime, patients with cough should be evaluated and treated according to evidence-based guidelines to mitigate or prevent the myriad of potential complications that are associated with coughing.

Typical symptoms and not positive reflux-cough correlation predict cure of gastroesophageal reflux disease related chronic cough after laparoscopic fundoplication: a retrospective study

Background

The effect of laparoscopic fundoplication on reflux-related chronic cough is unpredictable, the aim of the study is to investigate the predictive effect of positive reflux-cough correlation on the resolution of reflux-related chronic cough after anti-reflux surgery.

Methods

A 5 years retrospective review was performed. Logistic regression analysis was used to determine the independent predictors on the cure of chronic cough.

Results

Seventy-nine patients were included in this study, among which chronic cough was cured in 47 (59.5%) and significantly improved in 10 (12.7%) patients. Present of typical symptoms (odds ratio = 6.435,95% confidence interval [CI] = 1.427–29.032, p = 0.015) and number of Reflux episodes (impedance) ≥73 (odds ratio = 0.306, 95% confidence interval [CI] = 0.107–0.874, p = 0.027) were significantly associated with the cure of chronic cough.

Conclusions

laparoscopic fundoplicaiton is effective for the management of reflux-related chronic cough, particularly with the present of typical symptoms.

Trial registration

(Trial registration number: ChiCTR1800016444; Trial registration date: June 01, 2018)

Ambulatory pH-impedance-pressure monitoring as a diagnostic tool for the reflux-cough syndrome

Gastroesophageal reflux is considered to be a significant contributing factor to chronic unexplained cough. Patients are often presumed to have reflux-induced cough and are exposed to high-dose and long-term empirical therapy with proton pump inhibitors (PPIs) despite the limited treatment efficacy in this population. We aimed to assess the diagnostic value of 24-hour ambulatory pH-impedance-pressure monitoring for the diagnosis of reflux-induced chronic cough. In this multicenter study, we evaluated 192 patients with chronic cough using 24-hour pH-impedance-pressure monitoring off PPIs. Manometry was used to detect all cough bursts while pH-impedance allowed for the evaluation of all reflux episodes, including weakly acidic reflux. The symptom association probability was used to determine a temporal relationship between reflux and cough. A diagnosis of reflux-induced cough was made in 25.5% of the patients. If only acid reflux episodes were used, 22.4% of those patients would not have been diagnosed. Significantly more patients with reflux-induced cough had typical reflux symptoms (P = 0.031) and a pathological distal acid exposure time (P = 0.025) in comparison to patients without the diagnosis. A diagnosis of cough-induced reflux was made in 24.0% of the patients. Only 59% of all cough bursts were registered by the patients. Overall, only approximately one quarter of patients with chronic unexplained cough have reflux-induced cough, explaining the observation that the vast majority of patients with chronic cough do not benefit from antireflux therapy. pH-impedance-pressure monitoring helps to identify patients who are likely to have reflux as a cause of their chronic cough.

Reflux-cough syndrome: Assessment of temporal association between reflux episodes and cough bursts

BACKGROUND

Gastro-esophageal reflux can be the cause of chronic cough. In the assessment of the temporal association between reflux and cough, previous studies have used a two-minute time window, based on studies in patients with heartburn. However, it remains unclear whether the optimal time window duration for the evaluation of reflux-induced cough is two minutes as well. Therefore, we aimed to determine whether a two-minute time window is optimal to diagnose reflux-induced cough.

METHODS

In this multicenter study, 137 patients with chronic cough were evaluated using 24-h pH-impedance-pressure monitoring. Repetitive symptom association analysis was employed using an array of time windows of various duration. For each time window, the symptom association probability (SAP) and symptom index (SI) were calculated.

KEY RESULTS

A total of 4377 cough burst episodes and 5074 reflux episodes were detected. The number of patients with a positive SAP increased with increasing window duration until a plateau was reached around a time window duration of 1.5 min. Similarly, the SI increased steeply until a window duration of about 2 min, after which a linear increase was seen.

CONCLUSIONS AND INFERENCES

A two-minute time window seems appropriate for evaluation of the relationship between reflux and chronic cough using 24-h pH-impedance-pressure monitoring. A time window duration of 30 s or 1 min is too short to diagnose patients with reflux-induced cough accurately.

Determinants of reflux-induced chronic cough

OBJECTIVE

Gastro-oesophageal reflux is considered to be an important contributing factor in chronic unexplained cough. It remains unclear why some reflux episodes in the same patient causes cough while others do not. To understand more about the mechanism by which reflux induces cough, we aimed to identify factors which are important in triggering cough.

DESIGN

In this multicentre study, 49 patients with reflux-associated chronic cough were analysed using 24-hour pH-impedance-pressure monitoring. The characteristics of reflux episodes that were followed by cough were compared with reflux episodes not associated with cough.

RESULTS

The majority (72.4%) of the reflux episodes were acidic (pH<4). Compared with reflux episodes that were not followed by cough, reflux episodes that were followed by a cough burst were associated with a higher proximal extent (p=0.0001), a higher volume clearance time (p=0.002) and a higher acid burden in the preceding 15 min window (p=0.019) and higher reflux burden in the preceding 30 min window (p=0.044). No significant difference was found between the two groups when looking at the nadir pH, the pH drop, the acid clearance time or the percentage of reflux episodes which were acidic.

CONCLUSIONS

The presence of a larger volume of refluxate and oesophageal exposure to reflux for a longer period of time seems to play an important role in inducing cough, while the acidity of the refluxate seems to be less relevant. This helps explain the observation that most patients with chronic cough tend not to benefit from acid inhibitory treatment.

Respiratory disease and the oesophagus: reflux, reflexes and microaspiration

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

Cough reflex sensitization from esophagus and nose

The diseases of the esophagus and nose are among the major factors contributing to chronic cough although their role in different patient populations is debated. Studies in animal models and in humans show that afferent C-fiber activators applied on esophageal or nasal mucosa do not initiate cough, but enhance cough induced by inhaled irritants. These results are consistent with the hypothesis that activation of esophageal and nasal C-fibers contribute to cough reflex hypersensitivity observed in chronic cough patients with gastroesophageal reflux disease (GERD) and chronic rhinitis, respectively. The afferent nerves mediating cough sensitization from the esophagus are probably the neural crest-derived vagal jugular C-fibers. In addition to their responsiveness to high concentration of acid typical for gastroesophageal reflux (pH < 5), esophageal C-fibers also express receptors for activation by weakly acidic reflux such as receptors highly sensitive to acid and receptors for bile acids. The nature of sensory pathways from the nose and their activators relevant for cough sensitization are less understood. Increased cough reflex sensitivity was also reported in many patients with GERD or rhinitis who do not complain of cough indicating that additional endogenous or exogenous factors may be required to develop chronic coughing in these diseases.

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.

Weakly acidic gastroesophageal refluxes are frequently triggers in young children with chronic cough

OBJECTIVE

To evaluate whether the proportion of acid and weakly acidic refluxes preceding cough bursts could be different in infants, preschool- and school-aged children with chronic, unexplained cough.

PATIENTS AND METHODS

One hundred six children with unexplained chronic cough, not receiving acid suppressive therapy, underwent impedance-pH monitoring. They were divided into Group A: <2 years (21 pts), Group B: ≥2 to ≤6 years (41 pts), and Group C: >6 years (44 pts). Reflux was defined as acid (pH <4), weakly acidic (WA; pH 4-7), and weakly alkaline (pH >7).Cough episodes were considered temporally associated with gastroesophageal reflux (GER) when occurring within 2 min after a GER episode.

RESULTS

Impedance-pH detected 55.50 (39.00-76.00) reflux episodes/patient with an acid-to-WA reflux event ratio of 3.31 (1.55-8.33). This parameter was significantly lower in Group A (1.33 [0.41-3.40]) than in Group B (3.06 [2.00-6.50]; P < 0.05] and Group C (5.09 [2.34-12.43; P < 0.001]). No cough episode was preceded by weakly alkaline refluxes in any patient. During impedance-pH recording, 93 patients (87.7%) had at least one cough episode that had been preceded by impedance refluxes in 83 patients. In this latter group (83 pts), the median number of cough episodes was 12.0 (5.0-25.5), of which 48.15% (30.15-71.43%) were preceded by refluxes; GER-preceded cough episodes were similar in the three groups. The majority of children had cough episodes preceded by acid refluxes in the total population (78.3%), in Group B (80.5%) and in Group C (93.7%), but not in Group A (40.0%; P < 0.001).

CONCLUSIONS

In addition to acid, also a significant proportion of WA GER may precede cough episodes in young children with persistent cough, possibly explaining the inconstant effects of anti-acid treatment on respiratory symptoms.

Characterization of the upper esophageal sphincter response during cough

BACKGROUND

Vagal reflex initiated by esophageal stimulation and microaspiration can cause chronic cough in patients with gastroesophageal reflux disease (GERD). By raising intraabdominal pressure,cough can, in turn, predispose to GERD. The role of the upper esophageal sphincter (UES)in preventing esophagopharyngeal reflux during coughing is not well known. The aim of this study was to evaluate the UES response during coughing.

METHODS

We studied 20 healthy young (10 women; age, 27 ± 5 years) and 15 healthy elderly(nine women; age, 73 ± 4 years) subjects. Hard and soft cough-induced pressure changes in the UES, distal esophagus, lower esophageal sphincter, and stomach were determined simultaneously using high-resolution manometry and concurrent acoustic cough recordings.

RESULTS

Resting UES pressure was significantly higher in the young compared with the elderly subjects (42 ± 14 mm Hg vs 24 ± 9 mm Hg; P < .001). Cough induced a UES contractile response in all subjects. Despite lower UES resting pressures in the elderly subjects, the maximum UES pressure during cough was similar between the young and the elderly subjects (hard cough, 230 ± 107 mm Hg vs 278 ± 125 mm Hg, respectively; soft cough, 156 ± 85 mm Hg vs 164 ± 119 mm Hg, respectively; P not significant for both). The UES pressure increase over baseline during cough was significantly higher than that in the esophagus, lower esophageal sphincter, and stomach for both groups ( P < .001).

CONCLUSIONS

Cough induces a rise in UES pressure, and this response is preserved in elderly people. A cough-induced rise in UES pressure is significantly higher than that in the esophagus and stomach,thereby providing a barrier against retrograde entry of gastric contents into the pharynx.

Breaking the sound barrier? Pitfalls and benefits of acoustic cough monitoring

Traditionally push-button and symptom diaries have been used to document cough events, especially when examining temporal associations between cough and reflux events. More recently, acoustic devices have allowed more accurate recording of cough events, and compared with the latter traditional techniques reported 6-18 times more coughing. Whether the differences reported between these techniques represents disparities in subject groups or cough detection and quantification methods is unknown. In this issue of the American Journal of Gastroenterology, Kavitt et al. show that listeners of such recordings have a 4-fold increase in odds of recording cough events compared with patients using push-button techniques, and that even when using a 5-min window to assess temporal concordance/discordance, over 70% of coughs were not reported by the patients. These observations have potential significant implications when assessing temporal associations between cough and reflux, and thus any clinical decision making based on these data. This editorial examines both the findings of Kavitt et al. and discusses the pitfalls and benefits of validated accurate documentation of cough.

The relationship between gastroesophageal reflux and cough in children with chronic unexplained cough using combined impedance-pH-manometry recordings

INTRODUCTION

Assessment of the reflux-cough association in children is challenging. Esophageal (impedance) pH recording is sensitive to recognize reflux. However, cough recorded by an event marker, possibly lacks accuracy. We aimed to study the exact time relationship between reflux and cough in children with chronic cough.

METHODS

Twenty-six children (12 boys; 1-10.5 years) with chronic unexplained cough underwent ambulatory impedance-pH-manometry recordings. Manometry was used for precise cough recognition. Reflux was assessed with impedance-pH monitoring and defined as acid (pH <4), weakly acidic (WA) (pH 4-7), weakly alkaline (WALK) (pH ≥7), or acid only (pH <4 for ≥4 sec without impedance pattern). Cough was considered "induced by" reflux, if it started ≤2 min after reflux. The Symptom Association Probability (SAP) was calculated and considered positive if >95%. Cough-induced reflux if it occurred 30 sec before the reflux event.

RESULTS

Impedance-pH detected 30 (21-52) reflux episodes/patient (55.2% acid, 41.5% WA, and 3.3% WALK). Additionally 59 acid only events were identified [1 (0-21)/patient]. Manometry detected 47 (5-203) cough bursts/patient. Reflux-cough was found in 22/26 patients. Ten patients had a +SAP for reflux-cough (one acid, six WA, and three acid + WA gastroesophageal reflux [GER]), of which nine had a normal acid exposure. Six out of 10 patients with +SAP using manometry had a +SAP using the event marker. Cough-reflux was detected in 19 patients [3 (0-7)/patient]. Only a small fraction of the esophageal acid exposure [9.6 (0.4-31.8%)] was secondary to cough.

CONCLUSION

Both acid and WA GER may precede cough in children with unexplained cough, but cough does not induce GER. Objective cough recording improves symptom association analysis.

Combined lung-sound and reflux-monitoring: a pilot study of a novel approach to detect nocturnal respiratory symptoms in gastro-oesophageal reflux disease

BACKGROUND

Increased prevalence of respiratory symptoms has been commonly reported in patients with gastro-oesophageal reflux disease (GERD).

AIM

To introduce a novel Lung-Sound-Monitoring device that allows simultaneous measurement of both nocturnal respiratory symptoms and episodes of acidic and biliary refluxes.

METHODS

Nocturnal respiratory symptoms (coughing and wheezing) were continuously recorded in 20 healthy subjects and 30 reflux patients with respiratory symptoms in parallel to combined pH-monitoring and Bilitec measurement.

RESULTS

Analysis could be completed in 20 healthy subjects and in 25 patients with reflux. A clear temporal correlation to reflux phases was detected in 49% of coughing and 41% of wheezing events, respectively. Moreover, 89% of the coughing and 100% of the wheezing events succeeded reflux episodes. Finally, the technique was capable of assessing a statistically significant difference between patients and controls regarding the occurrence of these symptoms.

CONCLUSIONS

Our pilot study establishes the Lung-Sound-Monitoring system as a unique tool to measure objectively the temporal correlation between gastroesophageal reflux and the appearance of respiratory symptoms. It represents a useful technique to identify patients with respiratory symptoms due to reflux, and therefore allows one to determine and quantify the impact of therapeutic interventions such as antireflux therapy on respiratory symptoms.

Loss of alkalization in proximal esophagus: a new diagnostic paradigm for patients with laryngopharyngeal reflux

INTRODUCTION

Cervical esophageal pH monitoring using a pH threshold of <4 in the diagnosis of laryngopharyngeal reflux (LPR) is disappointing. We hypothesized that failure to maintain adequate alkalization instead of acidification of the cervical esophagus may be a better indicator of cervical esophageal exposure to gastric juice. The aim of this study was to define normal values for the percent time the cervical esophagus is exposed to a pH ≥7 and to use the inability to maintain this as an indicator for diagnosis of LPR.

MATERIAL AND METHODS

Fifty-nine asymptomatic volunteers had a complete foregut evaluation including pH monitoring of the cervical esophagus. Cervical esophageal exposure to a pH <4 was calculated, and the records were reanalyzed using the threshold pH ≥7. The sensitivity of these two pH thresholds was compared in a group of 51 patients with LPR symptoms that were completely relieved after an antireflux operation.

RESULTS

Compared to normal subjects, patients with LPR were less able to maintain an alkaline pH in the cervical esophagus, as expressed by a lower median percent time pH ≥ 7 (10.4 vs. 38.2, p < 0.0001). In normal subjects, the fifth percentile value for percent time pH ≥ 7 in the cervical esophagus was 19.6%. In 84% of the LPR patients (43/51), the percent time pH ≥ 7 were below the threshold of 19.6%. In contrast, 69% (35/51) had an abnormal test when the pH records were analyzed using the percent time pH < 4. Of the 16 patients with a false negative test using pH < 4, 11 (69%) were identified as having an abnormal study when the threshold of pH ≥ 7 was used.

CONCLUSION

Normal subjects should have a pH ≥7 in cervical esophagus for at least 19.6% of the monitored period. Failure to maintain this alkaline environment is a more sensitive indicator in the diagnosis of the LPR and identifies two thirds of the patients with a false negative test using pH <4.

Gastric juice from patients "on" acid suppressive therapy can still provoke a significant inflammatory reaction by human bronchial epithelial cells

BACKGROUND

Patients with reflux-related respiratory symptoms are frequently treated with proton pump inhibitors (PPI). It is unclear whether aspiration of gastric juice (GJ) from patients "on" PPI can provoke a similar bronchial inflammatory reaction than that observed in patients "off" medication. The goal of this study was to evaluate the effect of GJ from patients with and without PPI treatment on production of IL-8 by human primary bronchial epithelial cells (PBEC).

STUDY

PBEC were exposed during 24 hours to GJ (1/1000) from patients "on" (n=10) and "off" (n=13) PPI and to nonacidic gastric components (pepsin and bile acids). IL-8 concentration in supernatant was measured with enzyme-linked immunosorbent assay. Endotoxin level in GJ samples was analyzed with a LAL assay.

RESULTS

Exposure of PBEC to GJ from patients "on" PPI provoked a higher production of IL-8 than GJ from patients "off" PPI [279 pg/mL (36 to 498) vs. 11 pg/mL (9 to 27)]. A correlation was found between pH of GJ and IL-8 production (r=0.659, P=0.0006). No correlation was found between IL-8 production and concentration of bile acids or pepsin. Filtration (0.20 [mu]m) of GJ from patients "on" PPI reduced IL-8 production. A positive correlation was found between IL-8 production and endotoxin levels of GJ samples (1/1000) (r=0.654, P=0.0007).

CONCLUSIONS

Exposure of bronchial epithelial cells to GJ from patients "on" PPI is able to induce high IL-8 production. These results suggest that aspiration of GJ in patients treated with PPI might still be able to provoke a significant bronchial inflammatory reaction.

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.

Extraesophageal manifestations of gastroesophageal reflux disease: real or imagined?

PURPOSE OF REVIEW

Extraesophageal reflux disease is a common clinical presentation to gastroenterology as well as ear, nose and throat, allergy, and asthma clinics. The diagnosis and management of this condition is challenging. We review the current dilemma in this area and discuss the latest studies which help guide our therapies for patients with suspected extraesophageal reflux.

RECENT FINDINGS

Diagnostic approach to patients with extraesophageal reflux disease involved the use of insensitive tools, which have hampered the ability to correctly identify patients at risk. Empiric trial using proton pump inhibitors is still the recommended initial approach to those suspected of having reflux as the cause for extraesophageal symptoms such as asthma, chronic cough, or laryngitis. Diagnostic testing should be reserved to those unresponsive to therapy. Most recent studies suggest that ambulatory impedance/pH monitoring performed on therapy may be most likely to help exclude reflux as the cause for persistent symptoms. Recent randomized placebo-controlled studies on chronic laryngitis, cough, and asthma have been disappointing in showing benefit of acid suppressive therapy.

SUMMARY

Gastroduodenal reflux may cause symptoms such as chronic cough, asthma, or laryngitis. However, we are currently limited in our diagnostic ability to identify the subgroup of patients who might respond to acid suppressive therapy. Impedance/pH monitoring may be a step in the right direction; however, outcome studies are needed to better understand the role of acid or nonacid reflux in patients with extraesophageal symptoms.

Validation of an ambulatory cough detection and counting application using voluntary cough under different conditions

Background

While cough is an important defence mechanism of the respiratory system, its chronic presence is bothersome and may indicate the presence of a serious disease. We hereby describe the validation process of a novel cough detection and counting technology (PulmoTrack-CC™, KarmelSonix, Haifa, Israel).

Methods

Tracheal and chest wall sounds, ambient sounds and chest motion were digitally recorded, using the PulmoTrack^® hardware, from healthy volunteers coughing voluntarily while (a) laying supine, (b) sitting, (c) sitting with strong ambient noise, (d) walking, and (e) climbing stairs, a total of 25 minutes per subject. The cough monitoring algorithm was applied to the recorded data to detect and count coughs.

The detection algorithm first searches for cough 'candidates' by identifying loud sounds with a cough pattern, followed by a secondary verification process based on detection of specific characteristics of cough. The recorded data were independently and blindly evaluated by trained experts who listened to the sounds and visually reviewed them on a sonogram display.

The validation process was based on two methods: (i) Referring to an expert consensus as gold standard, and comparing each cough detected by the algorithm to the expert marking, we marked True and False, positive and negative detections.These values were used to evaluate the specificity and sensitivity of the cough monitoring system. (ii) Counting the number of coughs in longer segments (t = 60 sec, n = 300) and plotting the cough count vs. the corresponding experts' count whereby the linear regression equation, the regression coefficient (R²) and the joint-distribution density Bland-Altman plots could be determined.

Results

Data were recorded from 12 volunteers undergoing the complete protocol. The overall Specificity for cough events was 94% and the Sensitivity was 96%, with similar values found for all conditions, except for the stair climbing stage where the Specificity was 87% with Sensitivity of 97%. The regression equation between the PulmoTrack-CC™ cough event counts and the Experts' determination was with R² of 0.94.

Discussion

This validation scheme provides an objective and quantitative assessment method of a cough counting algorithm in a range of realistic situations that simulate ambulatory monitoring of cough. The ability to detect voluntary coughs under acoustically challenging ambient conditions may represent a useful step towards a clinically applicable automatic cough detector.

Characteristics of gastroesophageal reflux and potential risk of gastric content aspiration in children with cystic fibrosis

OBJECTIVES

Increased gastroesophageal reflux (GER) is common in children with cystic fibrosis (CF). We studied the occurrence of acid, weakly acidic (WA), and weakly alkaline (WALK) reflux in children with CF and evaluated a possible surrogate marker for risk of gastric content aspiration.

PATIENTS AND METHODS

Twenty-four children with CF underwent impedance-pH monitoring for detection of acid (pH < 4), WA (pH 4-7), and WALK-GER (pH > or = 7). In 11 children, cough was objectively recorded with esophageal manometry and the symptom association probability was calculated to determine the reflux-cough relation. Presence of bile acids (BA) was measured in the saliva of 65 patients with CF and 23 healthy children, respectively.

RESULTS

Sixteen of the 24 children had increased GER (esophageal acid exposure). The majority of reflux events were acidic in nature. WA reflux was less common and WALK reflux was rare. The sequence reflux-cough was found in 8 of the 11 children and 1 of 11 children had a positive symptom association probability for reflux-cough. The sequence cough-reflux was found in only 3 of the 11 children. Only a small fraction of the total esophageal acid and volume exposure was secondary to cough. Twenty-three of the 65 children with CF had BA in saliva compared with none of the healthy controls.

CONCLUSIONS

Although WA-GER is uncommon, acid GER is prevalent in children with CF. It is a primary phenomenon and is not secondary to cough. One third of the children with CF have BA in saliva, which may indicate an increased risk for aspiration. However, the impact of salivary BA and potential aspiration on CF pulmonary disease needs further investigation.

Cough and gastroesophageal reflux: insights from animal models

Chronic cough in gastroesophageal reflux disease (GERD) has been attributed to irritation of the esophagus and/or upper airways by reflux of gastric content. Animal models have provided insight into both of these putative mechanisms. In patients with chronic cough and GERD, stimuli associated with reflex in the esophagus sensitize the cough reflex. This sensitization can be reproduced in the guinea pig and is most likely mediated by the esophageal afferent nerve fibers carried by the vagus nerves. Studies in animals have identified several subtypes of vagal esophageal C-fibers that may subserve this function. The putative nociceptive vagal C-fibers in the guinea pig esophagus are stimulated by acid and express the TRPV1 and TRPA1 receptors that confer responsiveness to disparate noxious stimuli. Acute and/or chronic irritation of the upper airways by reflux may contribute to cough by stimulation and/or sensitization of the airway afferent nerves. Studies in animals have identified airway nerves that likely initiate cough due to aspirated reflux; have characterized their pharmacology; and have provided insight into changes of their sensitivity. Studies in animal models have also described the neurophysiology of reflexes that protect the airways from reflux. In conclusion, animal models provide mechanistic insight into the modulation of cough from the esophagus and the pharmacology of neural pathways mediating cough in GERD.

Damage to lung epithelial cells and lining fluid antioxidant defense by humic acid

Humic acid causes diseases including lung emphysema and fibrosis. Emerging evidence indicates that oxidative stress is involved in humic acid-induced effects. In the present study, we investigated generation of hydroxyl radicals from humic acid, as well as the effects of humic acid to lung epithelial cells and artificial alveolar lining fluid antioxidant mixture. The involvement of iron in humic acid-induced effects was also determined. We found that humic acid (concentration and time dependently) reduced the cell survival, increased caspase-3 activity, depleted GSH and raised lipid peroxidation in epithelial cells. Humic acid reduced antioxidant levels in the lining fluid antioxidant mix, which could be prevented by adding metal ion chelators. These findings suggest that humic acid causes oxidative stress in lung cells and alveolar lining fluid, which is most likely triggered by hydroxyl radicals produced directly from humic acid. Iron is probably involved in humic acid toxicity.

Acidification of the oesophagus acutely increases the cough sensitivity in patients with gastro-oesophageal reflux and chronic cough

Gastro-oesophageal reflux disease (GORD) is one of the most common causes of chronic cough; however, the mechanisms by which GOR initiates coughing are incompletely understood. We address the hypothesis that acidification of oesophagus acutely increases the cough reflex sensitivity in patients with GORD and chronic cough. Nine patients with GORD with chronic cough and 16 patients with GORD without cough were recruited. In a randomized double blind study, saline and acid (HCl, 0.1 mol L(-1)) were separately infused into oesophagus via naso-oesophageal catheter. Cough reflex sensitivity to inhaled capsaicin was determined immediately after completion of each infusion. Infusion of acid into oesophagus increased capsaicin cough reflex sensitivity in patients with GORD and chronic cough. In contrast, acid had no effect on the cough sensitivity in patients with GORD without cough. In a separate study, acid infusion into oesophagus did not affect the cough sensitivity in 18 healthy subjects. We conclude that acid in the oesophagus acutely increases the cough reflex sensitivity to capsaicin in patients with GORD and chronic cough. This phenomenon may contribute to the pathogenesis of cough due to GORD.

Salivary egf concentration in adults with reflux chronic laryngitis before and after treatment: preliminary results

The Laryngopharyngeal Reflux (LPR) physiopathology is still unknown. The Epidermal Growth Factor (EGF) is a biologically active salivary protein that aids in the rapid regeneration of the oropharyngeal and upper digestive tract mucosas. Salivary deficiency of this protein in patients with LPR has been demonstrated in previous studies.

AIM

To compare salivary EGF concentration in patients with LPR before and after treatment.

MATERIALS AND METHODS

In this prospective study twelve patients with GERD and moderate LPR were studied. Whole saliva samples were collected before and after treatment and salivary EGF concentration was determined using a commercially available ELISA kit (Quantikine).

RESULTS

There were eleven females and one male among the patients, the mean age was 49 years. The mean pre-treatment salivary EGF concentration was 2,867.6 pg/mL and the mean post treatment EGF concentration was 1,588.5 pg/mL. This difference was statistically significant (p=0.015).

DISCUSSION AND CONCLUSIONS

Although salivary EGF concentrations are higher before LPR treatment, the concentration is still much lower than the mean salivary EGF concentration in normal individuals without LPR, which suggests a primary disorder of this defense factor in individuals with LPR.

Diagnostic yield of oesophageal pH monitoring in patients with chronic unexplained cough

OBJECTIVE

One of the main causes of persistent cough is gastro-oesophageal reflux. In these patients, excessive oesophageal acid exposure and/or a temporal association between gastro-oesophageal reflux and cough can be demonstrated during 24-h pH monitoring. Impedance pH monitoring may have a higher yield than pH monitoring alone, but this technique is not yet widely available. The aim of this study was to assess the diagnostic yield of ambulatory 24-h oesophageal pH monitoring for the evaluation of chronic unexplained cough.

MATERIAL AND METHODS

Twenty-four-hour pH monitoring studies were analysed in 55 patients with chronic cough. In 14 of these studies concurrent ambulatory pressure monitoring was done. A cough episode was considered to be related to reflux if the cough occurred within two minutes after the onset of the reflux episode ("reflux-cough sequence"). Temporal relationships between cough and reflux were expressed by using the symptom association probability (SAP).

RESULTS

Thirty-seven patients actually coughed during the 24-h study. Eleven patients (20%) had a positive SAP for the reflux-cough sequence. In 5 patients, reflux followed coughing. Pathological oesophageal acid exposure was found in 15 subjects. Interestingly, only a minority (39.2%) of the cough bursts detected manometrically were marked by patients who had undergone both combined 24-h pH and pressure recording.

CONCLUSIONS

This study shows that, in a routine clinical setting, combined 24-h pH and pressure monitoring is useful in the evaluation of patients with chronic unexplained cough, as positive findings are not infrequently found and have diagnostic and therapeutic consequences.

Airway responses to esophageal acidification

The effects of esophageal acidification on airway function are unclear. Some have found that the esophageal acidification causes a small increase in airway resistance, but this change is too small to cause significant symptoms. The aims of this study were to investigate the effects of esophageal acidification on multiple measures of airway function in chloralose-anesthetized cats. The esophagus was cannulated and perfused with either 0.1 M PBS or 0.1 N HCl at 1 ml/min as the following parameters were quantified in separate experiments: diameter of bronchi (n = 5), tracheal mucociliary transport rate (n = 4), tracheobronchial mucus secretion (n = 7), and lung function (n = 6). We found that esophageal acidification for 10-30 min decreased bronchial diameters primarily of the smaller low-resistance airways (10-22%, P < 0.05), decreased tracheal mucociliary transport (53%, 8.7 +/- 2.4 vs. 4.1 +/- 1.3 mm/min, P < 0.05), increased tracheobronchial mucus secretion (147%, 3.4 +/- 0.7 vs. 8.4 +/- 2.6 mg/10 min, P < 0.05), and caused no change in total lung resistance or dynamic compliance (P > 0.05). Considering that tracheal mucociliary transport rate is governed in part by mucus secretion, we concluded that the primary airway response to esophageal acidification observed is increased mucus secretion. Airway constriction may act to assist in rapid secretion of mucus and to increase the effectiveness of coughing while not affecting lung resistance or compliance. Given the buffering capabilities of mucus, esophageal acidification activates appropriate physiological responses that may act to neutralize gastroesophageal reflux that reaches the larynx, pharynx, or lower airways.

Estudo comparativo da concentração salivar do fator de crescimento epidérmico em indivíduos com laringite crônica por doença do refluxo gastroesofágica antes e após o tratamento: resultados preliminares

Os mecanismos fisiopatológicos do refluxo laringofaríngeo (RLF) são pouco conhecidos. O Fator de Crescimento Epidérmico (EGF) é a proteína de produção salivar com maior ação na regeneração do epitélio da orofaringe e tubo digestivo alto, tendo sido demonstradas deficiências em sua concentração salivar em indivíduos com RLF. OBJETIVO: Comparar a concentração salivar de EGF em um mesmo indivíduo com RLF antes e após o tratamento. MATERIAL E MÉTODO: Neste estudo prospectivo doze indivíduos com DRGE e RLF de moderada intensidade tiveram sua saliva espontânea coletada antes e após o tratamento e controle da doença. A concentração salivar de EGF foi estabelecida através de exame de ELISA (Quantikine ®). RESULTADOS: Onze pacientes eram do sexo feminino e um do sexo masculino, com idade média de 49 anos. A concentração salivar de EGF pré-tratamento foi de 2.867,6pg/mL e a pós-tratamento foi 1.588,5pg/mL, sendo esta diferença estatisticamente significante (p=0,015). DISCUSSÃO E CONCLUSÕES: Apesar de a concentração salivar de EGF ser maior nos indivíduos antes do tratamento, esta não consegue alcançar àquela de uma população normal (estabelecida previamente), o que sugere uma deficiência primária deste importante fator de defesa em indivíduos com RLF.

Defining the relationship between gastroesophageal reflux and cough: probabilities, possibilities and limitations

The common co-existence of cough and gastroesophageal reflux disease (GORD) is well established. However, ascertaining cause and effect is more difficult for many reasons that include occurrence by chance of two common symptoms, the changing definition of GORD, equipment limitations and the lack of randomised controlled trials. Given these difficulties, it is not surprising that there is disparity of opinion between respiratory and gastroenterology society guidelines on the link between GORD and chronic cough. This commentary explores of these issues.

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.

Omeprazole reduces the response to capsaicin but not to methacholine in asthmatic patients with proximal reflux

OBJECTIVE

To study the relationships between airway responsiveness to methacholine and capsaicin, proximal or distal reflux and the effects of short-term acid inhibition.

MATERIAL AND METHODS

Twenty-nine asthmatics, not taking steroids regularly, underwent respiratory symptom measurements, 24-h dual-probe pH monitoring, and challenges with methacholine and capsaicin. Challenges and symptom measurements were repeated after 12 days' omeprazole treatment (20 mg b.i.d.). The results (median and range) were expressed as PD20 methacholine (mg) and PD5 capsaicin (dose causing five coughs, nmol).

RESULTS

Seventeen patients presented pathological reflux in the distal esophagus, and 17 in the proximal esophagus. At baseline no correlation was found between PD20 or PD5 and reflux. Treatment with omeprazole did not change bronchial responsiveness to methacholine (basal: 0.16 mg, 0.02-1.27; omeprazole: 0.15 mg, 0.02-1.60); omeprazole decreased the tussive response to capsaicin (basal: 0.08 nmol, 0.08-2.46; omeprazole: 0.61 nmol, 0.08-9.84, p<0.001) only in patients with pathological reflux. The decrease was positively correlated with proximal acid exposure (r2=0.70, p<0.001). Omeprazole reduced asthma symptoms in patients with proximal reflux, cough in those with proximal or distal reflux.

CONCLUSIONS

In asthmatics, inhibition of gastric acid secretion does not influence bronchial hyperresponsiveness but decreases tussive sensitivity and this effect is related to proximal reflux.

Chronic cough: state-of-the-art review

Cough is the most common presenting complaint in adults seeking medical treatment in an ambulatory setting. Chronic cough (persisting greater than 3 weeks) can be associated with myriad diseases that may overlap multiple medical specialties. For this reason, a thorough assessment of the patient with chronic cough relies on a multidisciplinary approach and close cooperation between pulmonary medicine, gastroenterology, and otolaryngology. Despite this daunting task, success can be achieved in up to 90% of patients with chronic cough if a systematic and thorough approach is used. The purpose of this review is to summarize the state-of-the-art in the diagnosis and treatment of chronic cough for the practicing otolaryngologist.

Analysis of the expression of heme oxygenase-1 gene in human alveolar epithelial cells exposed to cigarette smoke condensate

Airway epithelium is exposed to inhaled exogenous sources. Injury of the alveolar epithelium by cigarette smoking is presumed to be an important process in the pathogenesis of smoking-related pulmonary diseases. Current mechanistic assays that measure the toxicity of cigarette smoke focus on carcinogenesis. However, there is a need to design assays relevant to other disease processes. Oxidative stress is implicated in the pathogenesis of many respiratory diseases including chronic obstructive pulmonary disease. Therefore, we evaluated whether in vitro studies of cigarette smoking are appropriate to examine HO-1 mRNA expression. The human lung epithelial cell line A549 was exposed to the particulate fraction of cigarette smoke (Cigarette Smoke Condensate; CSC) and examined for the induction of HO-1 mRNA. HO-1 gene expression by CSC is increased dose-dependently. In comparison of the induction of HO-1 mRNA by CSC prepared from flue-cured or Burley tobacco, CSC from flue-cured tobacco seems to tend to induce an mRNA of HO-1 higher than CSC from Burley tobacco. The adaptation of HO-1 mRNA expression assay as a biologically relevant indicator of cigarette smoke-induced stress may be exemplified in this study whereby CSC derived from cigarette smoke positively correlated with an increase in HO-1 expression and the difference of the type of tobacco can be detected.

Complications of cough: ACCP evidence-based clinical practice guidelines

OBJECTIVES

To review the spectrum and frequency of complications associated with coughing.

DESIGN/METHODOLOGY

Ovid MEDLINE literature review (through March 2004) for all studies published in the English language, including case series and case reports, since 1966 using the MeSH terms "cough" and "complications."

RESULTS

The complications of cough appear to stem from physiologic events. The magnitude of pressures, velocities, and energy that is generated during vigorous coughing allow coughing to be an effective means of clearing the airways of excessive secretions and foreign material, and providing cardiopulmonary resuscitation; however, they can also cause a variety of profound physical and psychosocial complications. The adverse occurrences include cardiovascular, constitutional, GI, genitourinary, musculoskeletal, neurologic, ophthalmologic, psychosocial, respiratory, and skin complications, and a decrease in health-related quality of life.

CONCLUSIONS

Knowledge of the spectrum of complications should enable clinicians to appreciate (1) the impact of cough on patients, (2) why it is imperative to exhaust all possible diagnostic and therapeutic options to eliminate cough, and (3) why it is inappropriate to minimize a patient's complaint of cough and/or advise him/her to "live with it."

Chronic Cough Due to Gastroesophageal Reflux Disease

OBJECTIVES

To critically review and summarize the literature on cough and gastroesophageal reflux disease (GERD), and to make evidence-based recommendations regarding the diagnosis and treatment of chronic cough due to GERD.

DESIGN/METHODOLOGY

Ovid MEDLINE literature review (through March 2004) for all studies published in the English language and selected articles published in other languages such as French since 1963 using the medical subject heading terms "cough," "gastroesophageal reflux," and "gastroesophageal reflux disease."

RESULTS

GERD, singly or in combination with other conditions, is one of the most common causes of chronic cough. In patients with normal chest radiographic findings, GERD most likely causes cough by stimulation of an esophageal-bronchial reflex. When GERD causes cough, there may be no GI symptoms up to 75% of the time. While 24-h esophageal pH monitoring is the most sensitive and specific test in linking GERD and cough in a cause-effect relationship, it has its limitations. In addition, there is no general agreement on how to best interpret the test, and it cannot detect non-acid reflux events. Therefore, when patients fit the clinical profile that has a high likelihood of predicting that GERD is the cause of cough, antireflux medical therapy should be empirically instituted. While some patients improve with minimal medical therapy, others require more intensive regimens. When empiric treatment fails, it cannot be assumed that GERD has been ruled out as a cause of chronic cough. Rather, an objective investigation for GERD is then recommended because the empiric therapy may not have been intensive enough or medical therapy may have failed. Surgery may be efficacious when intensive medical therapy has failed in selected patients who have undergone an extensive objective GERD evaluation.

CONCLUSIONS

Accurately diagnosing and successfully treating chronic cough due to GERD can be a major challenge.

The diagnosis and management of gastro-oesophageal reflux in infants

Gastro-oesophageal reflux (GOR) and gastro-oesophageal reflux disease (GORD) occur frequently during the first months of life. Gastro-oesophageal reflux may be a primary gastro-intestinal motility disorder, but it may also be secondary to other conditions such as cow's milk protein allergy. Objective diagnosis can be difficult because there may be absence of correlation between history, results of pH monitoring and histology. Severe GORD may cause minor symptoms, and minor GOR may cause severe symptoms. Several different therapeutic interventions exist. Simply stated, thickened formula reduces regurgitation and alginates and proton pump inhibitors can be used to decrease acid GOR, depending on the severity of the GORD. Efficacy data of prokinetic drugs are either lacking or disappointing. Regarding side-effects, interest has been focused on cisapride, although other molecules have similar effects. Long-term side-effects such as the nutritional consequence of therapeutic management have been insufficiently studied, especially for the acid-reducing molecules.

Catheter-based pH monitoring: use in evaluation of gastroesophageal reflux disease symptoms (on and off therapy)

Tube-based ambulatory pH testing has rapidly evolved in the past 3 decades to become the standard by which other diagnostic approaches to gastroesophageal reflux disease are judged. Acid exposure 5 cm above the manometrically determined lower esophageal sphincter is the standard for documentation of pathologic acid exposure of the distal esophagus. Proximal esophageal or hypopharyngeal monitoring is an evolving technique that may shed light on patients with supraesophageal symptoms. The ability to simultaneously monitor esophageal and gastric acidity (usually in patients with persistent symptoms despite therapy) is another advantage of this technique. Whether the new system that allows simultaneous pH and impedance monitoring and the system that uses an implantable tubeless monitoring capsule will supplant this older but well-established technology remains to be determined.

The role of pH monitoring in extraesophageal gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is linked to several extraesophageal disease states including laryngitis, asthma, chronic cough, and noncardiac chest pain (NCCP). Although 24-hour pH monitoring is considered the "gold standard" in the diagnosis of typical GERD, it is also increasingly used in establishing the diagnosis of GERD in patients with extraesophageal symptoms. The clinical utility of pH monitoring in this patient population, however, remains controversial. In this article, the authors examine the role of pH monitoring in laryngitis, asthma, chronic cough, and NCCP.

Effect of cigarette smoking on haem-oxygenase expression in alveolar macrophages

We investigated the effect of chronic cigarette smoking on the expression of haem-oxygenase (HO)-1 and HO-2. Normal subjects and asymptomatic young current smokers with normal lung function tests underwent bronchoalveolar lavage for recovery of macrophages. Reverse transcription/polymerase chain reaction (RT-PCR) analysis showed no significant difference in HO-1 and HO-2 mRNA expression between the two groups. On the other hand, Western blot analysis showed a significant (P<0.05) reduction of HO-2 protein, but not of HO-1, in alveolar macrophages from smokers compared to normal. There was no significant differences by immunocytochemistry for HO-1 and HO-2 expression between the groups. We concluded that HO-2 expression is reduced in alveolar macrophages of smokers, possibly due to the oxidative stress of cigarette smoke. This may in turn lead to reduced protection against further oxidative insults.

Is ambulatory 24-h dual-probe pH monitoring useful in suspected ENT manifestations of GERD?

BACKGROUND AND AIMS

The present study is aimed at assessing the relationship between ear, nose and throat manifestations and proximal reflux in gastro-oesophageal reflux disease by using 24-h dual-probe pH monitoring.

PATIENTS AND METHODS

Fifty-eight patients were included: (;) 28 patients with suspected ear, nose and throat manifestations of gastrooesophageal reflux disease: (ii) 18 patients with typical symptoms of gastro-oesophageal reflux disease without extraoesophageal manifestations of gastro-oesophageal reflux disease; (iii) 12 healthy volunteers. Ambulatory 24-h dual-probe pH monitoring was performed in all patients. Oesophagogastroscopy was performed in all patients of groups I and II. Ear, nose and throat examination was performed in all patients with ear, nose and throat complaints.

RESULTS

At the upper oesophageal sphincter, results of pH monitoring were significantly different between groups I and III (0.009 < P < 0.02) and between groups I and II (0.008 < P < 0.03). When comparing data at the lower oesophageal sphincter, we found a significant difference between groups II and III (0.002 < P < 0.009) and between groups I and III (0.001 < P < 0.002). Endoscopic examination of the oesophagus did not show any significant difference between groups I and II. Laryngoscopy was abnormal in 86% of the patients with ear, nose and throat symptoms.

CONCLUSIONS

Ambulatory 24-h dual-probe pH monitoring is useful in the assessment of patients with suspected ear, nose and throat manifestations of gastro-oesophageal reflux disease, especially in the case of abnormal laryngoscopy.

Extraesophageal manifestations of GERD

The association between gastroesophageal reflux disease (GERD) and extraesophageal disease is often referred to as extraesophageal reflux (EER). This article reviews EER, discussing epidemiology, pathogenesis, diagnosis, and treatment with a focus on the most studied and convincing EER disorders-asthma, cough, and laryngitis. Although EER comprises a heterogeneous group of disorders, some general characterizations can be made, as follows. First, although GERD's association with extraesophageal diseases is well-established, definitive evidence of causation has been more elusive, rendering epidemiological data scarce. Secondly, regarding the pathogenesis of EER, 2 basic models have been proposed: direct injury to extraesophageal tissue by acid and pepsin exposure or injury mediated through an esophageal reflex mechanism. Third, because heartburn and regurgitation are often absent in patients with EER, GERD may not be suspected. Even when GERD is suspected, the diagnosis may be difficult to confirm. Although endoscopy and barium esophagram remain important tools for detecting esophageal complications, they may fail to establish the presence of GERD. Even when GERD is diagnosed by endoscopy or barium esophagram, causation between GERD and extraesophageal symptoms cannot be determined. Esophageal pH is the most sensitive tool for detecting GERD, and it plays an important role in EER. However, even pH testing cannot establish GERD's causative relationship to extraesophageal symptoms. In this regard, effective treatment of GERD resulting in significant improvement or remission of the extraesophageal symptoms provides the best evidence for GERD's pathogenic role. Finally, EER generally requires more prolonged and aggressive antisecretory therapy than typical GERD requires.

The role of proton pump inhibitors in the management of gastroesophageal reflux disease-related asthma and chronic cough

Gastroesophageal reflux disease (GERD) occurs in at least one third of patients with asthma and is recognized as a potential trigger for asthma symptoms. The results of studies conducted in patients with both asthma and GERD, in which proton pump inhibitor (PPI) therapy is used to evaluate its effect on asthma outcome, are inconsistent, and many of these studies suffer from different design flaws. However, it does appear that PPI treatment may improve nocturnal asthma symptoms in patients who also have GERD. Moreover, both daytime asthmatic symptoms and pulmonary function seem to improve in some patients with PPI treatment. There is evidence that more severe GERD might predict a more favorable asthma outcome with PPI therapy. For effective management of GERD-related asthma, PPIs should be used at a dose double that of the standard dose for a minimum of 2 to 3 months. Although GERD is also known to be an important cause of chronic cough, there have been only 2 placebo-controlled trials investigating the efficacy of PPI on GERD-related chronic cough. Results of both of these trials suggest that PPI treatment relieves GERD-related chronic cough. As with GERD-related asthma, it would seem reasonable to use a double-standard dose of a PPI for a minimum of 2 to 3 months in the management of GERD-related chronic cough. However, larger, adequately planned studies are needed to confirm the role of PPIs in the management of GERD-related asthma and chronic cough.

Improvement of respiratory symptoms following laparoscopic Nissen fundoplication

BACKGROUND

Laparoscopic fundoplication has become the standard of care for the management of symptomatic gastro-oesophageal reflux disease (GORD). Although atypical and respiratory symptoms are frequently described in standard texts in association with reflux, the response of respiratory symptoms to management of GORD has not been extensively studied.

METHODS

Herein is reported a prospective series of 29 patients who presented with predominantly respiratory symptoms. Typical and respiratory symptoms were graded according to a standard scale. All patients had preoperative investigations confirming GORD. These patients were treated by a laparoscopic Nissen fundoplication and followed up for a minimum of 14 months (range: 14-48 months). Patients were contacted and interviewed by an independent observer.

RESULTS

Conversion to open surgery was necessary in three patients. There were four significant complications. Ultimately control of typical reflux symptoms was achieved in 88%. Cough was completely relieved in 81% and improved in a further 13%. Wheeze and nocturnal bronchospasm was completely relieved in 50% and improved in the balance. Dysphagia remains a significant problem, with only 42% of patients completely free of trouble.

CONCLUSIONS

Overall the respiratory symptoms were improved in the majority of patients, with cough responding somewhat better than wheeze. Appropriate patient selection remains the greatest challenge when a patient with cough or wheeze that is considered to be due to GORD is referred for surgery.

Cough and paradoxical vocal fold motion

OBJECTIVES

The differential diagnosis and treatment of patients with chronic cough, paradoxical vocal fold motion, and disordered breathing can be a challenge to most practicing otolaryngologists. Tracheobronchial (ie, asthma, bronchitis, and tracheal stenosis), laryngeal (ie, vocal fold paralysis and neoplasms), and rhinologic (ie, allergies and rhinosinusitis) etiologies are commonly diagnosed and treated effectively. However, occasionally one is faced with patients who are refractory to medical treatment and have no obvious rhinologic, laryngeal or pulmonary cause.

STUDY DESIGN AND SETTING

We conducted a review of the literature.

METHODS

We present a thorough review of the current medical literature exploring the complex neurologic mechanisms involved in the production of cough and the relationship between gastroesophageal reflux disease, vagal neurapathy, and paradoxical vocal fold motion.

RESULTS

The diagnosis and successful treatment of chronic cough can be complex. It requires a thorough understanding of the neurologic mechanisms behind cough excitation and suppression. Successful treatment strategies include aggressive management of the patient's reactive airway disease, gastroesophageal reflux disease, and, in select cases, paradoxical vocal fold motion. This may involve a well-coordinated effort among pulmonologists, otolaryngologists, gastroenterologists, and speech pathologists.

CONCLUSION

Gastroesophageal reflux disease, vagal neuropathy, and paradoxical vocal fold motion are additional causes of chronic cough and disordered breathing that need to be considered, in the absence of obvious laryngotracheal and/or rhinologic pathology. A high index of suspicion is essential in making the diagnosis and formulating an effective multidisciplinary treatment plan for these patients.