Simultaneous tracheal and oesophageal pH measurements in asthmatic patients with gastro-oesophageal reflux

Gastroesophageal reflux disease in chronic obstructive pulmonary disease

Gastroesophageal reflux disease (GERD) is one of the most common comorbidities of chronic obstructive pulmonary disease (COPD). Decreased lower and upper esophageal sphincter pressures, esophageal dysmotility, high transdiaphragmatic pressure, and decreased saliva secretion have been implicated as mechanisms leading to the development of GERD in COPD. Clinically, comorbid GERD in COPD is reportedly associated with worse symptoms, quality of life, and lung function, as well as a high risk of exacerbations. Aspiration of regurgitation and the cholinergic-mediated esophagobronchial reflex play a significant role in the pathophysiology. Abnormal swallowing reflexes and discoordination of swallowing can worsen aspiration. The diagnosis of GERD is not based on a single criterion; however, various approaches, including questionnaires and endoscopic evaluations, can be widely applied in clinical settings. Due to the increased risk of esophageal and gastric cancers in patients with COPD, the threshold for endoscopic examination should be low. Acid inhibitory agents, such as proton pump inhibitors and histamine H2 receptor antagonists, and prokinetic agents, including mosapride and itopride, are clinically used to treat GERD. Endoscopic fundoplication can be performed in patients with GERD refractory to medical treatment. There is still insufficient evidence, but an increasing number of studies have suggested the clinical efficacy of treatment in patients with COPD and GERD. As GERD is an evaluative and treatable common disease, and access to evaluation and treatment is relatively easy, clinicians should provide adequate care for GERD in the management of COPD.

Management of comorbidities in difficult and severe asthma

Difficult-to-treat and severe asthma are challenging clinical entities. In the face of suboptimal asthma control, the temptation for clinicians is to reflexively escalate asthma-directed therapy, including increasing exposure to corticosteroids and commencement of costly but potent biologic therapies. However, asthma control is objectively and subjectively assessed based on measurable parameters (such as exacerbations or variability in pulmonary physiology), symptoms and patient histories. Crucially, these features can be confounded by common untreated comorbidities, affecting clinicians' assessment of asthma treatment efficacy.

Gastroesophageal Reflux Disease and Asthma: A Narrative Review

Gastroesophageal reflux disease (GERD) is defined by retrograde reflux of gastric contents to the esophagus leading to various signs and symptoms that range from heartburn/regurgitation to the development of extraesophageal respiratory syndromes like asthma. Although a cause-effect relationship has been proposed, evidence suggests that these two entities share a complex mechanism that may be reciprocal to each other. The understanding of the underlying mechanisms is imperial due to the fact that asthmatic patients may benefit from reflux therapy with subsequent improvement in pulmonary function testing and quality of life. This study has revised available literature in order to provide evidence for a nexus between GERD and asthma based on clinical correlation, pathophysiology, and pharmacologic management.

Prevalence and effects of gastro-oesophageal reflux during spirometry in subjects undergoing reflux assessment

Variability during spirometry can persist despite control of technical and personal factors. We postulate spirometry induces gastro-oesophageal reflux (GOR), which may cause variability and affect results of spirometry. Fifty-eight (58) subjects undergoing GOR investigation with oesophageal manometry and 24hr pH monitoring were recruited. Oesophageal dysmotility and GOR were assessed as part of clinical care. Subjects performed 2 sets of spirometry separated by a 10-minute rest period. The assessment of GOR during spirometry procedure (defined by a lower oesophageal pH<4) started from the first set of spirometry and concluded when the second set of spirometry was completed. We calculated variability (%) of FEV₁, FVC and PEFR within each set as well as changes over 10-minutes. Twenty-six subjects (45%) recorded GOR during assessment. Of these, 23 subjects recorded GOR during the 10-minute rest period. Four subjects had GOR recorded only during spirometry tests. We did not find variability of spirometry parameters between the groups with and without GOR during spirometry procedure. However, in subjects with GOR, we found small but significant reductions of PEFR (0.5L/s, 8%, p<0.001) and FEV₁ (84 mL, 3%, p = 0.048) in the second set of spirometry compared to the first spirometry set. This pilot study demonstrates that GOR can occur during and following spirometry. Presence of GOR during spirometry in this patient population caused small decreases in PEFR and FEV₁ when it is repeated 10-minutes later however not increase variability in a single series of measurements.

Bidirectional Association Between GERD and Asthma: Two Longitudinal Follow-Up Studies Using a National Sample Cohort

BACKGROUND

A relation between gastroesophageal reflux disease (GERD) and asthma has been suggested; however, causality has not been investigated.

OBJECTIVE

This study aimed to delineate the causal relation between GERD and asthma.

METHODS

Participants of the Korean National Health Insurance Service-National Sample Cohort 2002-2013 who were ≥20 years old were selected for this study. In study I, 116,502 patients with GERD were matched in a 1:2 ratio to 233,004 control I participants, and the hazard ratio (HR) of asthma in patients with GERD was analyzed. In study II, 104,146 patients with asthma were matched in a 1:1 ratio to 104,146 control II participants, and the HR for GERD in patients with asthma was analyzed. A stratified Cox-proportional hazards model was used. Subgroup analyses were performed according to age and sex.

RESULTS

In study I, 12.5% (14,595 of 116,502) of the GERD group and 7.8% (18,135 of 233,004) of the control I group presented asthma (P < .001). The GERD group demonstrated a 1.46-fold higher HR for asthma than the control I group (95% confidence interval [CI] = 1.42-1.49, P < .001). In study II, 16.9% (17,582 of 104,146) of the asthma group and 11.9% (12,393 of 104,146) of the control II group presented GERD (P < .001). The asthma group showed a 1.36-fold higher HR for GERD than the control II group (95% CI = 1.33-1.39, P < .001). All age and sex subgroups presented consistent results.

CONCLUSION

GERD and asthma had a bidirectional relation in the study population.

Study to determine the likely accuracy of pH testing to confirm nasogastric tube placement

Objective

To establish the likely accuracy of pH testing to identify gastric aspirates at different pH cut-offs to confirm nasogastric tube placement.

Methods

This prospective observational study included a convenience sample of adult patients who had two (one fresh and one frozen) gastric and oesophageal samples taken during gastroscopy or two bronchial and saliva samples taken during bronchoscopy. The degree of observer agreement for the pH of fresh and frozen samples was indicted by kappa (k) statistics. The sensitivities and specificities at pH ≤5.5 and the area under the receiver operating characteristics (ROC) curve at different pH cut-offs were calculated to identify gastric and non-gastric aspirates.

Results

Ninety-seven patients had a gastroscopy, 106 a bronchoscopy. There was complete agreement between observers in 57/92 (62%) of the paired fresh and frozen gastric samples (k=0.496, 95% CI 0.364 to 0.627). The sensitivity of a pH ≤5.5 to correctly identify gastric samples was 68% (95% CI 57 to 77) and the specificity was 79% (95% CI 74 to 84). The overall accuracy to correctly classify samples was between 76% and 77%, regardless of whether patients were taking antacids or not. The area under the ROC curve at different pH cut-offs was 0.74.

Conclusion

The diagnostic accuracy of pH ≤5.5 to differentiate gastric from non-gastric samples was low, regardless of whether patients were taking antacids or not. Due to the limited accuracy of the pH sticks and the operators’ ability to differentiate colorimetric results, there is an urgent need to identify more accurate and safer methods to confirm correct placement of nasogastric tubes.

Review article: gastro-oesophageal reflux disease in asthma and chronic obstructive pulmonary disease

BACKGROUND

When gastro-oesophageal reflux is causing symptoms or lesions in the oesophagus, this is referred to as gastro-oesophageal reflux disease (GERD). GERD can manifest itself through typical symptoms (heartburn, regurgitation) or may lead to extra-oesophageal symptoms. Extra-oesophageal manifestations of GERD gained increasing attention over the last decade, especially respiratory disorders, because of the prevalent co-occurrence with GERD. The role of GERD in the pathogenesis of respiratory disorders has become a topic of intense discussion.

AIM

To provide an overview of the current knowledge on the role of GERD in asthma and chronic obstructive pulmonary disease (COPD).

METHODS

PubMed was searched for relevant articles using the keywords: GERD, asthma, COPD, prevalence, treatment. Case reports were excluded, only English language articles were considered.

RESULTS

Estimates for the prevalence of GERD in asthma range from 30% to 90%, compared to an average of 24% in controls. In COPD patients, the prevalence of GERD ranges from 19% to 78% compared to an average of 18% in controls. These data indicate an increased prevalence of GERD in patients with asthma and COPD, although causality is not established and GERD treatment yielded inconsistent effects. Literature supports GERD as a risk factor for COPD-exacerbations and a predictor of the 'frequent-exacerbator'-phenotype.

CONCLUSIONS

Despite the high prevalence of GERD in asthma and COPD, a causal link is lacking. The results of anti-reflux therapy on pulmonary outcome are inconsistent and contradictory. Future studies will need to identify subgroups of asthmatics and COPD patients that may benefit from anti-reflux therapy (nocturnal or silent reflux).

Effectiveness of proton pump inhibitor in unexplained chronic cough

Background

Current guidelines recommend that patients with unexplained chronic cough undergo empirical proton pump inhibitor (PPI) treatment, but scientific evidence for this treatment is lacking. We investigated the effectiveness and appropriate dose of PPI therapy in chronic cough.

Methods

We included 27 patients with unexplained chronic cough after excluding subjects with positive response to postnasal drip medication. Subjects were randomized to a placebo, standard, and high dose of PPI groups with blinding. The drug or placebo was administered orally for 8 weeks, and the Leicester Cough Questionnaire (LCQ) score and visual analogue scale (VAS) scores were collected.

Results

The LCQ score in the PPI group significantly improved from 0 weeks (11.4 ± 1.4) to 4 weeks (14.8 ± 1.4) and to 8 weeks (17.1 ± 1.4), whereas that in the placebo group did not improve from 0 weeks (13.7 ± 1.1) to 8 weeks (11.8 ± 1.4); the difference between the 2 groups was significant (P < 0.001). In subgroup analysis according to reflux, significant improvements in the LCQ score were observed in the PPI group regardless of reflux (P < 0.001 in the reflux group and P < 0.001 in the no reflux group, respectively; P = 0.188 between the 2 groups). In addition, improvements in LCQ and VAS scores between the standard- and high-dose PPI groups were not significantly different; however, adverse reactions were induced by only the high dose (16.7%).

Conclusions

The results of this pilot study support the empirical use of the standard dose of PPI for 8 weeks in patients suffering from unexplained chronic cough regardless of whether reflux is present.

Trial registration

ClinicalTrial.gov NCT01888549 www.clinicaltrials.gov; cris.nih.go.kr KCT0000543 cris.nih.go.kr/

The Role of Microaspiration in the Pathogenesis of Gastroesophageal Reflux-related Chronic Cough

Background/Aims

Gastroesophageal reflux disease (GERD) is one of the main causes of chronic cough. We evaluated the role of microaspiration in the pathogenesis of reflux-related cough by determining the amount of lipid-laden macrophages (LLMs) in bronchoalveolar lavage (BAL) specimens.

Methods

A total of 161 cases of chronic cough were evaluated, and 36 patients (average age 48.2 years) were recruited for this single center prospective study. Patients with a history of smoking, angiotensin converting enzyme inhibitor usage, any abnormality on pulmonary function tests, abnormal chest X-rays, occupational or environmental exposures, or upper airway cough syndrome were excluded. GERD was evaluated by 24-hour esophageal impedance-pH monitoring. BAL specimens for LLM determination were obtained from 34 patients by flexible bronchoscopy.

Results

Patients with pathological intra-esophageal reflux according to multichannel intraluminal impedance and pH monitoring had higher LLM positivity in BAL specimens than patients without pathological reflux (8/14 in reflux positive group vs 1/22 in reflux negative group; P = 0.004). The BAL cell distribution was not different between the 2 groups (P = 0.574 for macrophages, P = 0.348 for lymphocytes, P = 0.873 for neutrophils and P = 0.450 for eosinophils).

Conclusions

Our results confirm the role of the microaspiration of refluxate in the pathogenetic mechanism of chronic cough. While bronchoscopy is indicated in patients with chronic cough, in addition to the routine airway evaluation, BAL and LLM detection should be performed. LLM can be used to diagnose aspiration in reflux-related chronic cough. Future studies are needed to evaluate the response to anti-reflux medications or surgery in patients with LLM positivity.

Weakly acidic pH reduces inflammatory cytokine expression in airway epithelial cells

Background

Aspiration lung disease (ALD) is a common cause of respiratory morbidity in children and adults with severe neurodisability (sND). Recent studies suggest that chronic microaspiration of gastric contents is associated with mild rather than low, airway acidification. We investigated inflammatory responses to infection by airway epithelial cells (AECs) exposed to weakly acidic media.

Methods

Using pH measurements from children with sND at high risk of ALD as a guide, we incubated AECs in weakly acidic (pH5.5–7.4) media alone; in combination with lipopolysaccharide (LPS); or prior to LPS stimulation at normal pH. Interleukin (IL) -6 and IL-8 expression were measured.

Results

IL-6/8 expression in AECs simultaneously exposed to weakly acidic media and LPS for 4 h was reduced with no effect on cell viability. Pre-incubation of AECs at weakly acidic pH also reduced subsequent LPS-induced cytokine expression. Suppression of inflammation was greatest at lower pHs (pH 5.5–6.0) for prolonged periods (16/24 h), but this also adversely affected cell viability.

Conclusion

AEC inflammatory responses to bacterial stimuli is markedly reduced in a mildly acidic environment.

Hiatal Hernia on Chest High-Resolution Computed Tomography and Exacerbation Rates in COPD Individuals

Background: Gastroesophageal reflux disease (GERD) is associated with frequent chronic obstructive pulmonary disease (COPD) exacerbations. Hiatal hernia (HH) contributes to GERD pathogenesis and is identifiable on chest high-resolution computed tomography (HRCT). We hypothesize that the presence of an HH on HRCT identifies those at increased risk for acute exacerbation of COPD. Methods: We retrospectively reviewed a prospectively enrolled cohort of smokers with and without airflow obstruction. HHs were identified visually on inspiratory HRCT. Individuals' demographic and clinical information was compared with secondary analysis performed using a propensity score generated matched cohort. Results: There were 523 COPD individuals and 607 unobstructed smokers. COPD individuals had more HHs than unobstructed smokers, (11.6% versus 6.1%, p < 0.001). COPD individuals with hernias were older, female, overweight and GERD positive as compared to those without hernia. There was no difference in self-reported exacerbation rates or hospitalizations per year, but similar severity of obstruction, smoking rates and long-term oxygen use. Analysis with the matched cohort revealed no significant difference in exacerbation rates. Conclusions: Presence of HHs on inspiratory HRCT scan did not predict worse symptoms or exacerbation rate in COPD individuals. Those with HHs were older, more obese, and predominantly female compared to those without HHs.

Extra-esophageal gastroesophageal reflux disease and asthma: understanding this interplay

Gastroesophageal reflux disease (GERD) is a condition that develops when there is reflux of stomach contents, which typically manifests as heartburn and regurgitation. These esophageal symptoms are well recognized; however, there are extra-esophageal manifestations of GERD, which include asthma, chronic cough, laryngitis and sinusitis. With the rising incidence of asthma, there is increasing interest in identifying how GERD impacts asthma development and therapy. Due to the poor sensitivity of endoscopy and pH monitoring, empiric therapy with proton pump inhibitors (PPIs) is now considered the initial diagnostic step in patients suspected of having GERD-related symptoms. If unresponsive, diagnostic testing with pH monitoring off therapy and/or impedance/pH monitoring on therapy, may be reasonable in order to assess for baseline presence of reflux with the former and exclude continued acid or weakly acid reflux with the latter tests. PPI-unresponsive asthmatics, without overt regurgitation, usually have either no reflux or causes other than GERD. In this group, PPI therapy should be discontinued. In those with GERD as a contributing factor acid suppressive therapy should be continued as well as optimally treating other etiologies requiring concomitant treatment. Surgical fundoplication is rarely needed but in those with a large hiatal hernia, moderate-to-severe reflux by pH monitoring surgery might be helpful in eliminating the need for high-dose acid suppressive therapy.

Approach to chronic cough: the neuropathic basis for cough hypersensitivity syndrome

Chronic cough is a common symptom that can be difficult to manage because associated causes may remain elusive and treatment of any associated cause may not provide relief. Current antitussives have limited efficacy and undesirable side-effects. Patients with chronic cough describe sensory symptoms suggestive of upper airway and laryngeal neural dysfunction, and report cough triggered by low-level physical and chemical stimuli supporting the concept of cough reflex hypersensitivity. Mechanisms underlying peripheral and central augmentation of the afferent cough pathways have been identified. Chronic cough is a neuropathic condition that could be secondary to sensory nerve damage caused by inflammatory, infective and allergic factors. Recent success in the treatment of chronic cough with agents used for treating neuropathic pain such as gabapentin and amitryptiline would also support this concept. Research into neuropathic cough may lead to the discovery of more effective antitussives.

The effects of concomitant GERD, dyspepsia, and rhinosinusitis on asthma symptoms and FeNO in asthmatic patients taking controller medications

Background

Losing the sense of smell, which suggests eosinophilic rhinosinusitis, is a subjective symptom, sometimes reported in asthmatic patients taking controller medication. Upper abdominal symptoms, suggesting gastroesophageal reflux disease (GERD) or functional dyspepsia, occur also in these patients. However, the relationship between these symptoms, concomitant with asthma, and the intensity of eosinophilic airway inflammation remains obscure.

Objective

To assess the symptoms of asthma and rhinosinusitis, and to examine the relationship between the symptoms and bronchial inflammation, a new questionnaire, the G scale, was developed. To investigate the effects of GERD, dyspepsia, and rhinosinusitis on asthma symptoms and bronchial inflammation, the symptoms of asthma and rhinosinusitis obtained by the G scale, upper abdominal symptoms obtained by the modified F scale, a questionnaire for GERD and dyspepsia, and fractional exhaled nitric oxide (FeNO) were analyzed.

Methods

A prospective, observational study was performed in four hospitals in Gunma prefecture, and a retrospective analysis was done using data obtained from five hospitals in Gunma prefecture and Fukui prefecture, Japan. A total of 252 patients diagnosed as having asthma participated in the prospective study.

Results

The frequency of daytime phlegm or losing the sense of smell had a positive correlation with FeNO levels in asthmatic patients taking controller medication. Upper abdominal symptoms, as well as symptoms suggesting rhinitis, were well correlated with asthma symptoms. However, neither upper abdominal symptoms nor rhinitis symptoms increased FeNO levels, which reflect eosinophilic airway inflammation during treatment for asthma. On the other hand, the degree of upper abdominal symptoms or dyspepsia symptoms had a weak but significant negative correlation with FeNO levels.

Conclusion

Daytime phlegm and losing the sense of smell suggest that eosinophilic airway inflammation persists, despite anti-inflammatory therapy, in patients with asthma. Although rhinitis and GERD made the subjective symptoms of asthma worse, they did not seem to enhance eosinophilic airway inflammation.

Lung diffusion capacity in children with respiratory symptoms and untreated GERD

BACKGROUND

Gastroesophageal reflux disease (GERD) is associated with many respiratory disorders, among which, chronic cough, laryngitis, and asthma are among the most common. We investigated lung function, including gas diffusion capacity, in children with poor asthma control or chronic laryngitis with untreated GERD.

MATERIAL AND METHODS

A total of 71 children, aged 6-17 years, with chronic respiratory and other symptoms suggestive for GERD, were enrolled and divided into 2 groups: chronic laryngitis and asthma. Participants underwent 24-hour pH monitoring and lung function assessment, measurement of single-breath diffusing capacity of the lung for carbon monoxide (DLCO), and fraction of exhaled nitric oxide (FENO) measurement.

RESULTS

24-hour pH monitoring was positive for GERD in 92.1% of preselected children with asthma and 90.1% of children with chronic recurrent laryngitis. All flows (PEF, MEF75, MEF50, and MEF25) were significantly lower in the asthma group, while FENO and DLCO were significantly lower in the laryngitis group. A significant inverse relationship was found between DLCO and all reflux indexes in the laryngitis group. Each unit change of Johnson-DeMeester score and Boix-Ochoa score increased the odds for significantly lower DLCO in laryngitis patients by 3.9% and 5.5%, respectively.

CONCLUSIONS

In children with uncontrolled asthma and chronic laryngitis, the regurgitation of gastric contents due to GERD contributes to poor asthma control and aggravation of chronic laryngitis. Despite having normal lung function, the gas diffusion capacity should be controlled in patients with GERD and chronic laryngitis, and it might be the very first abnormality in distal airways.

Lung function in patients with gastro-esophageal reflux disease and respiratory symptoms

The aim of this study was to investigate lung function in patients with gastro-esophageal reflux disease (GERD) who present respiratory symptoms suggestive of the possibility of co-morbid asthma. The study encompassed 20 patients (9 women and 11 men; age range from 11 to 68 years) diagnosed with GERD and presenting with chronic cough and other non-specific periodic respiratory complaints. The control group consisted of closely gender and age-matched 20 subjects without any gastrointestinal or respiratory symptoms. All patients and control subjects were tested for lung function, which encompassed spirometric and flow-volume variables. We found that none of the GERD patients had lung function abnormalities characteristic of asthma. There were, however, decreases in forced expired volume in 1 s, forced vital capacity, and in maximal instantaneous forced expiratory flows in the GERD patients compared with the healthy subjects. We conclude that cough accompanying GERD is unlikely to be associated with the presence of co-morbid asthma, but rather suggests a mild airway inflammation developing as a sequel of GERD. The corollary is that chronic cough should prompt physician's attention to consider diagnostic work-up toward the possibility of GERD.

Experimental study for the mechanism of gastroesophageal-reflux-associated asthma

Epidemiologic studies have shown a strong association between gastroesophageal reflux (GER) and asthma, especially in children. Diagnosing GER can be difficult in some patients when GER presents solely with asthma. The aim of this study was to explore the relationship between GER and asthma with animal model. Sixty rats were randomly divided into six equal groups, GER group, GER-associated-asthma group, allergic asthma group, and their control groups. The cytokine levels and concentration of inflammatory cells in bronchoalveolar lavage (BAL) were determined. The BAL of the rats with allergic asthma contained higher concentration of Interleukin-5 (IL-5) and more eosinophils than those of rats with GER-associated-asthma. This demonstrates that assaying the concentrations of IL-5 and inflammatory cells in BAL may be an effective method of distinguishing GER-associated asthma from allergic asthma.

Gastroesophageal reflux disease and childhood asthma

PURPOSE OF REVIEW

Gastroesophageal reflux disease (GERD) is common in children with asthma and may be present with or without symptoms. Clinicians, influenced by position statements in national guidelines, have routinely treated children with poorly controlled asthma with various anti-GERD medications. This practice is based on the pervasive but unproven belief that GERD is an important determinant of poor asthma control.

RECENT FINDINGS

Clinical studies show that GERD is highly prevalent in children with asthma, with estimates as high as 80%, but nearly half of the children are asymptomatic. However, there is no conclusive evidence per se that asymptomatic GERD informs asthma control, and treatment of GERD in the few controlled trials available for review does not substantively improve asthma outcomes. In a recent large controlled clinical trial, treatment with a proton-pump inhibitor (PPI) was not only ineffective, but adverse effects were common, including an increased prevalence of symptomatic respiratory infections.

SUMMARY

Current evidence does not support the routine use of anti-GERD medications in the treatment of poorly controlled asthma of childhood. However large controlled trials of children symptomatic of both GERD and asthma have not been conducted, and in this case the benefits of treatment, although unproven, might outweigh the risks.

The association between reflux esophagitis and airway hyper-reactivity in patients with gastro-esophageal reflux

BACKGROUND

The association of gastro-esophageal reflux (GER) with a wide variety of pulmonary disorders was recognized. We aimed to evaluate the effect of GER-induced esophagitis on airway hyper-reactivity (AHR) in patients and the response to treatment.

MATERIALS AND METHODS

In this cohort study, 30 patients attending the gastrointestinal clinic of a university hospital with acid reflux symptoms were included. All patients were evaluated endoscopically and divided into case group with esophagitis and control group without any evidence of esophagitis. Spirometry and methacholine test were done in all patients before and after treatment of GER with pantoprazole 40 mg daily for six months.

RESULTS

There was a significant difference in the rate of positive methacholine test between the cases (40%) and the controls (6.7%) prior to anti-acid therapy (P < 0.0001). After six months of treatment, the frequency of positive methacholine test diminished from 40 to 13.3% in the case group (P < 0.05) but did not change in the controls (P = 0.15).

CONCLUSION

The presence of esophagitis due to GER would increase the AHR and treatment with pantoperazole would decrease AHR in patients with proved esophagitis and no previous history of asthma after six months.

Airway reflux, cough and respiratory disease

It is increasingly accepted that the effects of gastro-oesophageal reflux are not limited to the gastrointestinal tract. The adjacent respiratory structures are also at risk from material ejected from the proximal oesophagus as a result of the failure of anatomical and physiological barriers. There is evidence of the influence of reflux on several respiratory and otorhinological conditions and although in many cases the precise mechanism has yet to be elucidated, the association alone opens potential novel avenues of therapy to clinicians struggling to treat patients with apparently intractable respiratory complaints. This review provides a description of the airway reflux syndrome, its effects on the lung and current and future therapeutic options.

Association of gastroesophageal reflux disease with asthma control

Gastroesophageal reflux disease (GERD) may make asthma difficult to control and may be a potential risk factor for frequent asthma exacerbations, but the mechanisms of the relationship between GERD and not well-controlled asthma remain unclear. The aim of this study was to explore the association of GERD with asthma control in adults. Patients with asthma were consecutively recruited, and Asthma Control Test (ACT) and Reflux Diagnostic Questionnaire scores were determined. The patients were categorized into not well-controlled asthma and well-controlled asthma groups according to the ACT score. Univariate and multivariate logistic regression analyses were performed to evaluate the relationship between GERD and not well-controlled asthma. Seven hundred and sixty-eight patients with asthma were enrolled. The mean ACT score was 18.2 ± 3.6, and there were 161 (21.0%) patients with not well-controlled asthma. The Reflux Diagnostic Questionnaire score was 10.5 ± 4.7, and 212 (27.6%) patients were complicated by GERD. Multivariate logistic regression analyses revealed the independent association of GERD with not well-controlled asthma (odds ratio, 3.12; 95% confidence interval, 1.53-4.88) after other established contributors to asthma control were adjusted. In conclusion, there is an association of GERD with not well-controlled asthma, independent of other potential contributors to asthma control.

Airway irritation and cough evoked by acid: from human to ion channel

Inhalation or aspiration of acid solution evokes airway defense responses such as cough and reflex bronchoconstriction, resulting from activation of vagal bronchopulmonary C-fibers and Aδ afferents. The stimulatory effect of hydrogen ion on these sensory nerves is generated by activation of two major types of ion channels expressed in these neurons: a rapidly activating and inactivating current mediated through ASICs, and a slow sustaining current via activation of TRPV1. Recent studies have shown that these acid-evoked responses are elevated during airway inflammatory reaction, revealing the potential convergence of a wide array of inflammatory signaling on these ion channels. Since pH in the airway fluid drops substantially in patients with inflammatory airway diseases, these heightened stimulatory effects of acid on airway sensory nerves may play a part in the manifestation of airway irritation and excessive cough under those pathophysiological conditions.

Protective role of aerodigestive reflexes against aspiration: study on subjects with impaired and preserved reflexes

BACKGROUND & AIMS

Direct evidence to support the airway protective function of aerodigestive reflexes triggered by pharyngeal stimulation was previously demonstrated by abolishing these reflexes by topical pharyngeal anesthesia in normal subjects. Studies have also shown that these reflexes deteriorate in cigarette smokers. Aim of this study was to determine the influence of defective pharyngeal aerodigestive reflexes on airway protection in cigarette smokers.

METHODS

Pharyngoglottal Closure reflex; PGCR, Pharyngo-UES Contractile reflex; PUCR, and Reflexive Pharyngeal Swallow; RPS were studied in 15 healthy non-smokers (24.2±3.3 SD y, 7 males) and 15 healthy chronic smokers (27.3±8.1, 7 males). To elicit these reflexes and to evaluate aspiration, colored water was perfused into the hypopharynx at the rate of 1 mL/min. Maximum volume of water that can safely dwell in the hypopharynx before spilling into the larynx (Hypopharyngeal Safe Volume; HPSV) and the threshold volume to elicit PGCR, PUCR, and RPS were determined in smokers and results compared with non-smokers.

RESULTS

At baseline, RPS was elicited in all non-smokers (100%) and in only 3 of 15 smokers (20%; P<.001). None of the non-smokers showed evidence of laryngeal spillage of water, whereas 12 of 15 smokers with absent RPS had laryngeal spillage. Pharyngeal anesthesia abolished RPS reflex in all non-smokers resulting in laryngeal spillage. The HPSV was 0.61±0.06 mL and 0.76±0.06 mL in non-smokers and smokers respectively (P=.1).

CONCLUSIONS

Deteriorated reflexive pharyngeal swallow in chronic cigarette smokers predispose them to risks of aspiration and similarly, abolishing this reflex in non-smokers also results in laryngeal spillage. These observations directly demonstrate the airway protective function of RPS.

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.

A nocturnal decline of salivary pH associated with airway hyperresponsiveness in asthma

Salivary pH is associated with esophageal acid reflux and neutralization of esophageal acid. In this study, we assessed the association between nocturnal decline of salivary pH and airway hyperresponsiveness. Salivary pH was serially assessed in 9 patients with mild asthma (7 men and 2 women; mean age 33.3 years; mean %predicted FEV(1.0) 89.4%) and 10 healthy volunteers (6 men and 4 women; mean age 31.2 years) using a pH indicator tape. The buffering capacity of saliva was defined as the median effective dose (ED(50)) for acidification of saliva with 0.01 N HCl, and airway responsiveness was defined as the dose of methacholine producing a 35% fall in Grs (PD(35)-Grs). There was a significant correlation between the values obtained from the pH indicator tape and those obtained from the electrometric pH meter. Using the indicator tape for sequential monitoring, we observed a nocturnal fall (ΔpH) in salivary pH in all subjects. A significant correlation was found between airway hyperresponsiveness (PD(35)-Grs) and either ΔpH or ED(50) in mildly asthmatic patients. Vagal reflux dysfunction might contribute to nocturnal salivary pH as well as to airway hyperresponsiveness in mild asthmatics.

Chronic 'cough hypersensitivity syndrome': a more precise label for chronic cough

Chronic cough remains a challenge to many clinicians because there is often no diagnostic link to causation, and because indirect antitussives are largely ineffective. Chronic cough can also be a predominant symptom associated with many chronic respiratory diseases such as COPD, asthma and pulmonary fibrosis. Chronic cough itself does impair the quality of life and is associated with psychological impairment. The symptoms associated with chronic cough include persistent tickling or irritating sensation in the chest or throat, hoarse voice, dysphonia or vocal cord dysfunction. Currently, the clinical diagnosis of cough is associated with chronic cough caused by airway eosinophilic conditions such as asthma, gastrooesophageal reflux disease or post-nasal drip (or upper airway syndrome), which implies cause and effect, or with chronic cough associated with other diseases such as COPD, cancer or heart failure, that does not necessarily imply cause and effect. A recently-recognised category is idiopathic cough, with no associated or causative diagnosis. We suggest that there is a better label needed for chronic cough, that includes the common association with a hypersensitive cough response to tussive stimuli such as capsaicin or citric acid. This would invoke a hypersensitive syndrome, and there are good reasons to use a new label that would encompass the problem of chronic cough: the chronic 'cough hypersensitivity syndrome'. This would focus the problem on the cough symptomatology and lead to greater focus on understanding the mechanisms of cough sensitisation, with the ultimate aim of obtaining more effective antitussives.

Determinants of exhaled breath condensate pH in a large population with asthma

BACKGROUND

Exhaled breath condensate (EBC) pH is 2 log orders below normal during acute asthma exacerbations and returns to normal with antiinflammatory therapy. However, the determinants of EBC pH, particularly in stable asthma, are poorly understood. We hypothesized that patients with severe asthma would have low EBC pH and that there would be an asthma subpopulation of patients with characteristically low values.

METHODS

We studied the association of EBC pH with clinical characteristics in 572 stable subjects enrolled in the Severe Asthma Research Program. These included 250 subjects with severe asthma, 291 with nonsevere asthma, and 31 healthy control subjects.

RESULTS

Overall, EBC in this population of stable, treated study subjects was not lower in severe asthma (8.02; interquartile range [IQR], 7.61-8.41) or nonsevere asthma (7.90; IQR, 7.52-8.20) than in control subjects (7.9; IQR, 7.40-8.20). However, in subjects with asthma the data clustered below and above pH 6.5. Subjects in the subpopulation with pH < 6.5 had lower fraction of exhaled NO (FeNO) values (FeNO = 22.6 ± 18.1 parts per billion) than those with pH ≥ 6.5 (39.9 ± 40.2 parts per billion; P < .0001). By multiple linear regression, low EBC pH was associated with high BMI, high BAL neutrophil counts, low prebronchodilator FEV(1) ratio, high allergy symptoms, race other than white, and gastroesophageal reflux symptoms.

CONCLUSION

Asthma is a complex syndrome. Subjects who are not experiencing an exacerbation but have low EBC pH appear to be a unique subpopulation.

Risk of Barrett's oesophagus, oesophageal adenocarcinoma and reflux oesophagitis and the use of nitrates and asthma medications

OBJECTIVE

To investigate the relationship between use of asthma medication and nitrates and risk of reflux oesophagitis, Barrett's oesophagus and oesophageal adenocarcinoma.

MATERIAL AND METHODS

Data were collected on use of asthma medication and nitrates at least 1 year before interview from patients with reflux oesophagitis, Barrett's oesophagus and oesophageal adenocarcinoma. Associations between use of asthma medications and nitrates and the risk of reflux oesophagitis, Barrett's oesophagus and oesophageal adenocarcinoma were estimated using multiple logistic regression.

RESULTS

Nine hundred and forty-one subjects were recruited: 230 reflux oesophagitis, 224 Barrett's oesophagus, 227 oesophageal adenocarcinoma patients and 260 population controls. Barrett's oesophagus patients were more likely than controls to have had a diagnosis of asthma (odds ratio 2.15, 95% confidence interval 1.15-4.03) and to have used asthma medications (odds ratio 2.13, 95% confidence interval 1.09-4.16). No significant associations were observed between use of asthma medication or nitrates and reflux oesophagitis or oesophageal adenocarcinoma.

CONCLUSIONS

Gastro-oesophageal reflux symptoms appear to confound the association between asthma medication use and Barrett's oesophagus. However, it is possible that asthma medications may increase the risk of Barrett's oesophagus by other mechanisms.

The relationship between gastroesophageal reflux and asthma: an update

Asthma and gastroesophageal reflux disease (GERD) are both common conditions and, hence, they often coexist. However, asthmatics have been found to have a much greater prevalence of GERD symptoms than the general population. There remains debate regarding the underlying physiologic mechanism(s) of this relationship and whether treatment of GERD actually translates into improved asthma outcomes. Based on smaller trials with somewhat conflicting results regarding improved asthma control with treatment of GERD, current guidelines recommend a trial of GERD treatment for symptomatic asthmatics even without symptoms of GERD. However, recently a large multicenter trial demonstrated that the treatment of asymptomatic GERD with proton-pump inhibitors did not improve asthma control in terms of pulmonary function, rate of asthma exacerbations, asthma-related quality of life, or asthma symptom frequency. These data suggest empiric treatment of asymptomatic GERD in asthmatics is not a useful practice. This review article provides an overview of the epidemiology and pathophysiologic relationships between asthma and GERD as well as a summary of current data regarding links between treatment of GERD with asthma outcomes.

Identification of Intrinsic Airway Acidification in Pulmonary Tuberculosis

Exhaled breath condensate acidification reflects the presence of airway acidification. Mycobacterium tuberculosis is an organism particularly sensitive to acidity. We aimed to determine if there is evidence of airway acidification in a cross section of patients with active tuberculosis.We enrolled 51 subjects with active tuberculosis in Ghana and Thailand, and compared them to control subjects. We collected exhaled breath condensate, and assayed for pH after gas standardization.Exhaled breath condensate pH from the control group revealed a median of 7.9 (7.7 - 8.0, n = 21), significantly higher than the active pulmonary tuberculosis patients who had a median pH of 7.4 (7.0 - 7.7; n = 51; p=0.002). Presence or absence of antibiotic therapy did not affect EBC pH values.These exhaled breath condensate data support the theory that airways become acidic in active tuberculosis infection. This may be a mechanism of immune response and pathology not previously considered.

Gastroesophageal reflux disease and asthma

PURPOSE OF REVIEW

Asthma and gastroesophageal reflux disease (GERD) are both common diseases, and hence they often coexist. However, the coexistence of asthma and GERD is far more frequent than chance association. There remains debate regarding the mechanism of this relationship and whether treatment of GERD improves asthma outcomes.

RECENT FINDINGS

Recent data have confirmed the high prevalence of GERD among patients with asthma. Many asthmatic patients with GERD documented by pH probe do not have classic symptoms of GERD and are considered to have 'silent GERD'. On the basis of smaller trials with somewhat conflicting results regarding improved asthma control with treatment of GERD, consensus guidelines recommend a trial of GERD treatment for symptomatic asthmatic patients even without symptoms of GERD. Recently, a large multicenter trial demonstrated that the treatment of asymptomatic GERD with proton pump inhibitors did not improve asthma control in terms of pulmonary function, rate of asthma exacerbations, asthma-related quality of life, or asthma symptom frequency.

SUMMARY

Asthmatic patients have more GERD than the general population. There is not a clear understanding of why this is true. Current guidelines recommend that physicians consider treating patients who have poorly controlled asthma for GERD, even without GERD symptoms. Recent data suggest that this is not a useful practice for mild-to-moderate asthmatic patients.

Effect of systemic alcohol and nicotine on airway protective reflexes

OBJECTIVES

Injection of water into the pharynx induces contraction of the upper esophageal sphincter (UES), triggers the pharyngo-UES contractile reflex (PUCR), and at a higher volume, triggers an irrepressible swallow, the reflexive pharyngeal swallow (RPS). These aerodigestive reflexes have been proposed to reduce the risks of aspiration. Alcohol ingestion can predispose to aspiration and previous studies have shown that cigarette smoking can adversely affect these reflexes. It is not known whether this is a local effect of smoking on the pharynx or a systemic effect of nicotine. The aim of this study was to elucidate the effect of systemic alcohol and nicotine on PUCR and RPS.

METHODS

Ten healthy non-smoking subjects (8 men, 2 women; mean age: 32+/-3 s.d. years) and 10 healthy chronic smokers (7 men, 3 women; 34+/-8 years) with no history of alcohol abuse were studied. Using previously described techniques, the above reflexes were elicited by rapid and slow water injections into the pharynx, before and after an intravenous injection of 5% alcohol (breath alcohol level of 0.1%), before and after smoking, and before and after a nicotine patch was applied. Blood nicotine levels were measured.

RESULTS

During rapid and slow water injections, alcohol significantly increased the threshold volume (ml) to trigger PUCR and RPS (rapid: PUCR: baseline 0.2+/-0.05, alcohol 0.4+/-0.09; P=0.022; RPS: baseline 0.5+/-0.17, alcohol 0.8+/-0.19; P=0.01, slow: PUCR: baseline 0.2+/-0.03, alcohol 0.4+/-0.08; P=0.012; RPS: baseline 3.0+/-0.3, alcohol 4.6+/-0.5; P=0.028). During rapid water injections, acute smoking increased the threshold volume to trigger PUCR and RPS (PUCR: baseline 0.4+/-0.06, smoking 0.67+/-0.09; P=0.03; RPS: baseline 0.7+/-0.03, smoking 1.1+/-0.1; P=0.001). No similar increases were noted after a nicotine patch was applied.

CONCLUSIONS

Acute systemic alcohol exposure inhibits the elicitation PUCR and RPS. Unlike cigarette smoking, systemic nicotine does not alter the elicitation of these reflexes.

Acid aspiration-induced airways hyperresponsiveness in mice

The role of gastroesophageal reflux and micro-aspiration as a trigger of airways hyperresponsiveness (AHR) in patients with asthma is controversial. The role of acid reflux and aspiration as a direct cause of AHR in normal subjects is also unclear. We speculated that aspiration of a weak acid with a pH (1.8) equivalent to the upper range of typical gastric contents would lead to AHR in naive mice. We further speculated that modest reductions in aspirate acidity to a level expected during gastric acid suppression therapy (pH 4.0) would impede aspiration-induced AHR. BALB/c female mice were briefly anesthetized with isoflurane and allowed to aspirate 75 microl of saline with HCl (pH 1.8, 4.0, or 7.4) or underwent sham aspiration. Mice were re-anesthetized 2 or 24 h later, underwent tracheostomy, and were coupled to a mechanical ventilator. Forced oscillations were used to periodically measure respiratory impedance (Zrs) following aerosol delivery of saline and increasing doses of methacholine to measure for AHR. Values for elastance (H), airways resistance (R(N)), and tissue damping (G) were derived from Zrs. Aspirate pH of 1.8 led to a significant overall increase in peak R(N), G, and H compared with pH 4.0 and 7.4 at 2 and 24 h. Differences between pH 7.4 and 4.0 were not significant. In mice aspirating pH 1.8 compared with controls, airway lavage fluid contained more neutrophils, higher protein, and demonstrated higher permeability. We conclude that acid aspiration triggers an acute AHR, driven principally by breakdown of epithelial barrier integrity within the airways.

Effects of asymptomatic proximal and distal gastroesophageal reflux on asthma severity

RATIONALE

Silent gastroesophageal reflux (GER) is common in patients with asthma, but it is unclear whether GER is associated with worse asthma symptoms or reduced lung function.

OBJECTIVES

To determine in patients with poorly controlled asthma, whether proximal or distal esophageal reflux is associated with asthma severity, symptoms, physiology, or functional status.

METHODS

Baseline asthma characteristics were measured in patients with asthma enrolled in a multicenter trial assessing the effectiveness of esomeprazole on asthma control. All participants underwent 24-hour esophageal pH probe monitoring. Lung function, methacholine responsiveness, asthma symptoms, and quality-of-life scores were compared in subjects with and without GER.

MEASUREMENTS AND MAIN RESULTS

Of 304 participants with probe recordings, 53% had reflux. Of 242 participants with recordings of proximal pH, 38% had proximal reflux. There was no difference in need for short-acting bronchodilators, nocturnal awakenings, dose of inhaled corticosteroid, use of long-acting beta-agonists, lung function, or methacholine reactivity between individuals with and without proximal or distal GER. Participants with GER reported more use of oral corticosteroids and had worse asthma quality of life and subjects with proximal GER had significantly worse asthma quality of life and health-related quality of life compared with participants without GER.

CONCLUSIONS

Asymptomatic GER is not associated with distinguishing asthma symptoms or lower lung function in individuals with suboptimal asthma control who are using inhaled corticosteroids. Patients with proximal reflux report significantly worse asthma and health-related quality of life despite lack of physiologic impairment or increase in asthma symptoms. Clinical trial registered with www.clinicaltrials.gov (NCT00069823).

Pulmonary inflammation and airway hyperresponsiveness in a mouse model of asthma complicated by acid aspiration

Several studies have indicated a strong association between asthma and aspiration of stomach contents. However, the complex association between these inflammatory processes has not been studied extensively in animal models. In the present study, we developed an animal model to evaluate the inflammatory cell, chemokine, and airway responses to asthma complicated by aspiration. The model was produced by sensitizing mice to cockroach allergens from house-dust extracts. Mice with asthma-like airway responses then were inoculated intratracheally with either an acidic solution or saline. Acid aspiration increased airway hyperresponsiveness in mice with asthma for at least 8 h. After 6 h, the combined injury caused an additive, not synergistic, increase in airway hyperresponsiveness and neutrophil recruitment to the airways. Although cysteinyl leukotrienes in bronchoalveolar lavage fluid were higher after acid aspiration, treatment with a receptor antagonist before aspiration did not diminish airway hyperresponsiveness. Vagal mechanisms reportedly mediate airway responses in acid aspiration; however, pretreatment with an anticholinergic agent did not reduce airway responses to acid. These results are consistent with an effective model of the acute effects of aspiration on the allergic lung. Further studies could examine how various forms of aspiration influence the severity of asthma.

Prevalence of gastroesophageal reflux in lung transplant candidates with advanced lung disease

OBJECTIVE

To assess the esophageal function profile and the prevalence of gastro-esophageal reflux (GER) in lung transplant candidates.

METHODS

From July of 2005 to November of 2006, a prospective study was conducted involving 55 candidates for lung transplantation at the Santa Casa de Misericórdia Hospital in Porto Alegre, Brazil. Prior to transplantation, patients underwent outpatient stationary esophageal manometry and 24-h esophageal pH-metry using one and two electrodes.

RESULTS

Abnormal esophageal manometry was documented in 80% of the patients, and 24% of the patients presented pathological acid reflux. Digestive symptoms presented sensitivity and specificity for GER of 50% and 61%, respectively. Of the patients with chronic obstructive pulmonary disease, 94% presented abnormal esophageal manometry, and 80% presented lower esophageal sphincter hypotonia, making it the most common finding. Patients with bronchiectasis presented the highest prevalence of GER (50%).

CONCLUSIONS

In patients with advanced lung disease, GER is highly prevalent. In the population studied, digestive symptoms of GER were not predictive of pathological acid reflux. The role that GER plays in chronic rejection should be examined and clarified in future studies.

A MCh test pre-post esophageal acidification in detecting GER-related asthma

The direct effect of gastro-esophageal reflux (GER) on lung function is still debated. Objective. To investigate the role of esophageal acidification in affecting airway response to MCh in GER-related versus atopic asthmatics and to assess specificity and sensitivity of events. Subjects. A total of 56 never-smoking, mild asthmatics: 27 non-atopic asthmatics and acid GER (GER+ve) and 29 atopic asthmatics without any GER (GER-ve). Methods. Each subject performed an MCh challenge in baseline (MCh(b)), and 30 minutes after an acid drink (125 mL at pH = 2; MCh(ac)), one day apart. PD(20)FEV(1) MCh(b) and MCh(ac) were compared by estimating the area under the ROC curve (AU-ROC). Results. GER+ve and GER-ve subjects (well matched in baseline) had a different duration of esophageal acid contact (24-hour monitoring; pH-24h AU(4)), and PD(20)FEV(1) MCh(ac) (both p < 0.001). AU-ROC was 86.3% (76% to 97%, 95%CI). Sensitivity and specificity of changes were 82.8% (72.9% to 92.7%, 95%CI) and 85.2% (75.9% to 94.5%, 95%CI), respectively. The difference in MCh threshold that maximized both the sensitivity and specificity level was 100 mu g. Conclusions. The esophageal acidification identified GER-related asthma with a good level of both sensitivity and specificity by enhancing the MCh response only in the presence of acid GER. Data are supporting the effectiveness of this procedure for clinical purposes.

Sleep-related problems in common medical conditions

Common medical problems are often associated with abnormalities of sleep. Patients with chronic medical disorders often have fewer hours of sleep and less restorative sleep compared to healthy individuals, and this poor sleep may worsen the subjective symptoms of the disorder. Individuals with lung disease often have disturbed sleep related to oxygen desaturations, coughing, or dyspnea. Both obstructive lung disease and restrictive lung diseases are associated with poor quality sleep. Awakenings from sleep are common in untreated or undertreated asthma, and cause sleep disruption. Gastroesophageal reflux is a major cause of disrupted sleep due to awakenings from heartburn, dyspepsia, acid brash, coughing, or choking. Patients with chronic renal disease commonly have sleep complaints often due to insomnia, insufficient sleep, sleep apnea, or restless legs syndrome. Complaints related to sleep are very common in patients with fibromyalgia and other causes of chronic pain. Sleep disruption increases the sensation of pain and decreases quality of life. Patients with infectious diseases, including acute viral illnesses, HIV-related disease, and Lyme disease, may have significant problems with insomnia and hypersomnolence. Women with menopause have from insomnia, sleep-disordered breathing, restless legs syndrome, or fibromyalgia. Patients with cancer or receiving cancer therapy are often bothered by insomnia or other sleep disturbances that affect quality of life and daytime energy. The objective of this article is to review frequently encountered medical conditions and examine their impact on sleep, and to review frequent sleep-related problems associated with these common medical conditions.

Efficacy of esomeprazole for treatment of poorly controlled asthma

BACKGROUND

Gastroesophageal reflux is common among patients with asthma but often causes mild or no symptoms. It is not known whether treatment of gastroesophageal reflux with proton-pump inhibitors in patients who have poorly controlled asthma without symptoms of gastroesophageal reflux can substantially improve asthma control.

METHODS

In a parallel-group, double-blind trial, we randomly assigned 412 participants with inadequately controlled asthma, despite treatment with inhaled corticosteroids, and with minimal or no symptoms of gastroesophageal reflux to receive either 40 mg of esomeprazole twice a day or matching placebo. Participants were followed for 24 weeks with the use of daily asthma diaries, spirometry performed once every 4 weeks, and questionnaires that asked about asthma symptoms. We used ambulatory pH monitoring to ascertain the presence or absence of gastroesophageal reflux in the participants. The primary outcome was the rate of episodes of poor asthma control, as assessed on the basis of entries in asthma diaries.

RESULTS

Episodes of poor asthma control occurred with similar frequency in the placebo and esomeprazole groups (2.3 and 2.5 events per person-year, respectively; P=0.66). There was no treatment effect with respect to individual components of the episodes of poor asthma control or with respect to secondary outcomes, including pulmonary function, airway reactivity, asthma control, symptom scores, nocturnal awakening, or quality of life. The presence of gastroesophageal reflux, which was documented by pH monitoring in 40% of participants with minimal or no symptoms, did not identify a subgroup of patients that benefited from treatment with proton-pump inhibitors. There were fewer serious adverse events among patients receiving esomeprazole than among those receiving placebo (11 vs. 17).

CONCLUSIONS

Despite a high prevalence of asymptomatic gastroesophageal reflux among patients with poorly controlled asthma, treatment with proton-pump inhibitors does not improve asthma control. Asymptomatic gastroesophageal reflux is not a likely cause of poorly controlled asthma. (ClinicalTrials.gov number, NCT00069823.)

Obstructive sleep apnea syndrome and asthma: what are the links?

Recent data suggest that obstructive sleep apnea syndrome (OSAS) is an independent risk factor for asthma exacerbations. Neuromechanical reflex bronchoconstriction, gastroesophageal reflux, inflammation (local and systemic), and the indirect effect on dyspnea of OSAS-induced cardiac dysfunction have been suggested as mechanisms that lead to worsening asthma control in patients with concomitant OSAS. Vascular endothelial growth factor-induced airway angiogenesis, leptin-related airway changes, and OSAS-induced weight gain also may play a common mechanistic role linking both disorders. Several studies have confirmed that asthmatic patients are more prone to develop OSAS symptoms than are members of the general population. The common asthmatic features that promote OSAS symptoms are nasal obstruction, a decrease in pharyngeal cross sectional area, and an increase in upper airway collapsibility. Clarifying the nature of the relationship between OSAS and asthma is a critical area with important therapeutic implications.

Recurrent respiratory infections

The child who has recurrent infections poses one of the most difficult diagnostic challenges in pediatrics. The clinician faces a two-fold challenge in determining first whether the child is normal or has a serious disease, and then, in the latter case, how to confirm or exclude the diagnosis with the minimum number of the least invasive tests. It is hoped that, in the absence of good-quality evidence for most clinical scenarios, the experience-based approach described in this article may prove a useful guide to the clinician.

Sleep and Obstructive Lung Diseases

Asthma and chronic obstructive pulmonary disease (COPD) are common obstructive lung diseases affecting millions of people in the United States. As sleep disorders are also common, it is not surprising that many people with obstructive lung disease also suffer from sleep disorders. However, people with COPD and those with asthma have worse sleep quality and more sleep-related problems when compared to people with other chronic health problems. In addition, a pathologic relationship may exist between obstructive sleep apnea (OSA) and obstructive lung diseases. This review focuses on the epidemiology, pathogenesis, and clinical implications of sleep disturbances in asthma and COPD.