Systematic review of outcomes for endoscopic sinus surgery and subsequent aspirin desensitization in aspirin-exacerbated respiratory disease

Objective:To review and evaluate outcomes of patients with aspirin-exacerbated respiratory disease(AERD)following endoscopic sinus surgery and subsequent aspirin desensitization.Methods:Electronic searches of OVID MEDLINE(1948 to September 10,2019),EMBASE(1980 to September 10,2019),and PubMed were performed on September 10,2019.A systematic review of the literature was performed using the 2009 PRISMA guidelines.Studies with both preoperative and postoperative data for patients with AERD who underwent sinus surgery and aspirin desensitization were considered appropriate for inclusion.Publications were written in English and included patients aged 18 years or older.Results:Six studies met inclusion criteria for this systematic review.The primary outcome measure was change in symptom profile measured by patient-reported quality of life scores.The results demonstrate statistically significant improvement in symptoms following endoscopic sinus surgery,with sustained improvement following aspirin desensitization.Revision surgery rates were significantly lower in patients maintained on aspirin therapy.Conclusion:This review suggests that surgery followed by aspirin desensitization results in improvement in both subjective and objective outcome measures.The adjunctive use of aspirin desensitization allows for long-term stability in symptom scores.Recurrence of polyps and worsening symptoms requiring revision surgery occurs when aspirin maintenance therapy is inter-rupted.

Aspirin-exacerbated respiratory disease:Update on medical management

Aspirin-exacerbated respiratory disease(AERD)is frequently diagnosed in patients with severe type 2 airway inflammation presenting with nasal polyps and severe asthma.It has been associated with a recalcitrant course with high medical and surgical requirements.The advent of recent biological and other targeted treatments show promise in the medical management of patient with AERD.The goal of complete disease control where patients no longer require recurrent surgical procedures,systemic corticosteroid exposure and may live with a stable and relatively normal quality of life is now within reach.Further work is necessary to identify biomarkers predictive of treatment response.

The importance of timely diagnosis of aspirin-exacerbated respiratory disease for patient health and safety

Backgroud:Aspirin-exacerbated respiratory disease(AERD)is a difficult-to-treat syndrome where timely diagnosis and initiation of disease-specific therapies are pertinent to improved patient outcomes.Objective:To characterize the most common timeline for development of the clinical triad[asthma,nasal polyposis,and reactions to nonsteroidal anti-inflammatory drugs(NSAIDs)],identify barriers to prompt diagnosis of AERD,and describe indications for an aspirin challenge to facilitate accurate diagnosis.Methods:Six hundred ninety-seven patients with diagnosed AERD and history of at least one sinus surgery to remove nasal polyps were identified in the Brigham and Women’s Hospital AERD registry.Patient reported age at disease onset of asthma,nasal polyposis,and age of first NSAID reaction were obtained from 2013 to 2019 at enrollment.Results:Of the 697 patients identified,diagnosis of asthma preceded diagnosis of nasal polyposis and first NSAID reaction,although there was considerable variability between patients.Conclusions:Prompt diagnosis of AERD is important for patient and provider education and improved care of this difficult-to-treat population of patients.Consider diagnostic aspirin challenge in patients without historical reactions to NSAIDs who have an otherwise compatible clinical history,specifically in patients who take daily low-dose aspirin,leukotriene modifiers,avoid NSAIDs,or who are severely symptomatic at baseline where it would be difficult to identify an acute worsening of symptoms.

Pathogenesis of NSAID-induced reactions in aspirin-exacerbated respiratory disease

It is well-established that following ingestion of aspirin or any other inhibitor of cyclooxygenase-1, patients with Samter’s disease, or aspirin-exacerbated respiratory disease (AERD) develop the sudden onset of worsening respiratory clinical symptoms, which usually in-volves nasal congestion, rhinorrhea, wheezing and bronchospasm. Gastrointestinal distress, nausea, a pruritic rash and angioedema can also occasionally develop. However, the underlying pathologic mechanism that drives these clinical reactions remains elusive. Pretreatment with medications that inhibit the leukotriene pathway decreases the severity of clinical reactions, which points to the involvement of cysteinyl leukotrienes (cysLTs) in the pathogenesis of these aspirin-induced reactions. Furthermore, studies of aspirin challenges in carefully-phenotyped patients with AERD have confirmed that both proinflammatory lipid mediators, predominantly cysLTs and prostaglandin (PG) D 2, and the influx of effector cells to the respiratory tissue, contribute to symptom development during aspirin-induced reactions. Mast cells, which have been identified as the major cellular source of cysLTs and PGD 2, are likely to be major participants in the acute reactions, and are an attractive target for future pharmacotherapies in AERD. Although several recent studies support the role of platelets as inflammatory effector cells and as a source of cysLT overproduction in AERD, it is not yet clear whether platelet activation plays a direct role in the development of the aspirin-induced reactions. To further our understanding of the pathogenesis of aspirin-induced reactions in AERD, and to broaden the pharmacotherapeutic options available to these patients, additional investigations with targeted clinical trials will be required.

Endogenous cannabinoids may regulate chronic inflammation in aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease(AERD)is characterized by the triad of chronic rhinosinusitis with nasal polyposis,adult-onset asthma and non-IgE mediated reactions to aspirin and other cyclooxygenase-1(COX-1)inhibitors.Patients with AERD are dependent on COX-1 activity to maintain production of prostaglandin(PG)species,such as PGE2,which maintain physiologic levels of inflammation and limit the production of pro-inflammatory cysteinyl leukotrienes.The endogenous cannabinoid system is a family of immunomodulatory lipids and their innate g-protein coupled receptors that are closely related to arachidonic acid and may modulate inflammation via several pathways,including the direct production of metabolically active prostaglandin glycerol-esters.A recent pilot study has identified the significant up-regulation of the peripherally expressed,type-2 cannabinoid receptor(CB2)in AERD nasal polyps versus control tissues from patients with either allergic fungal rhinosinusitis or no history of chronic sinonasal inflammation.These early findings suggest the involvement of increased endogenous cannabinoid activity in prostaglandin deficient states such as AERD.Future study is needed to explore the significance of these findings,with specific investigation of the impact of CB2 activation on markers of airway inflammation,as well as the potential to measure CB2 expression as a screening biomarker for the evaluation of unrecognized disease.

Advanced nanomedicines and immunotherapeutics to treat respiratory diseases especially COVID-19 induced thrombosis

Immunotherapy and associated immune regulation strategies gained huge attraction in order to be utilized for treatment and prevention of respiratory diseases.Engineering specifically nanomedicines can be used to regulate host immunity in lungs in the case of respiratory diseases including coronavirus disease 2019(COVID-19)infection.COVID-19 causes pulmonary embolisms,thus new therapeutic options are required to target thrombosis,as conventional treatment options are either not effective due to the complexity of the immunethrombosis pathophysiology.In this review,we discuss regulation of immune response in respiratory diseases especially COVID-19.We further discuss thrombosis and provide an overview of some antithrombotic nanoparticles,which can be used to develop nanomedicine against thrombo-inflammation induced by COVID-19 and other respiratory infectious diseases.We also elaborate the importance of immunomodulatory nanomedicines that can block pro-inflammatory signalling pathways,and thus can be recommended to treat respiratory infectious diseases.

Short-term effects of low-level PM_(2.5),PM_(10),O_(3),and tropical meteorological conditions on emergency department visits for respiratory diseases in Haikou,China

Objective:To assess the correlation between atmospheric pollutants,meteorological factors,and emergency department visits for respiratory diseases in Haikou City.Methods:Daily data on atmospheric pollutants,meteorological factors,and emergency department visits for respiratory diseases in Haikou City from 2018 to 2021 were collected.The Spearman rank correlation test was used to analyze the correlation,and a distributed lag non-linear model was employed to analyze the health effects and lag impacts of environmental factors.Subgroup analyses were conducted based on sex and age.Results:According to the criteria of International Classification of Diseases(ICD-10:J00-J99),a total of 221913 cases were included,accounting for 21.3%of the total emergency department visits in Haikou City.For every 1℃increase in temperature,the risk of emergency department visits increased by 1.029%(95%CI 1.016%-1.042%).Relative humidity greater than 80%reduced the risk of visits,while higher atmospheric pressure(>1010 hpa)also decreased the likelihood of daily emergency department visits.Higher concentrations of PM_(2.5)(30-50μg/m^(3)),PM10(>60μg/m^(3)),and O_(3)(75-125μg/m^(3))were associated with increased visits.Higher temperatures(>25℃)have a greater impact on females and children aged 0-14 years,while males are more sensitive to low atmospheric pressure.Individuals aged 65 and above exhibited increased sensitivity to O_(3)concentration,and the effects of PM2.5,PM10,and O_(3)are more pronounced in individuals over 14 years old.Conclusions:Short-term exposure to high temperatures,particulate matter pollutants(PM_(2.5)and PM_(10)),and ozone(O_(3))is associated with increased emergency department visits for respiratory diseases.

Respiratory Mechanics, Respiratory Muscle Strength, Control of Ventilation and Gas Exchange in Patients with Autoimmune Liver Disease

Objectives: To assess respiratory elastance and resistive properties in patients with autoimmune liver disorders using the passive relaxation expiration technique and compare findings to a group of patients with non-autoimmune liver disease and control subjects. These findings were then related to control of ventilation and gas exchange. A secondary objective was to assess respiratory muscle strength and gas exchange and their relation to respiratory mechanics. Methods: Measurements included respiratory elastance and resistance using the passive relaxation method. Pulmonary function, gas exchange and control of ventilation were assessed using standard methods. Results: a) Compared to control subjects, Ers in patients with liver disease was on average 50% greater than in controls;b) mean respiratory resistance, expressed as the respiratory constants, K1 and K2 in the Rohrer relationship, Pao/V’ = K1 + K2V’, was not different from control resistance;c) mean maximal inspiratory and maximal expiratory pressures averaged 36% and 55% of their respective control values;d) inspiratory occlusion pressure in 0.1 sec (P0.1) was increased and negatively associated with FVC;and e) increases in P0.1, mean inspiratory flow (Vt/Ti) and presence of respiratory alkalosis confirmed the increase in ventilatory drive. Despite inspiratory muscle weakness in patients, P0.1/Pimax averaged 5-fold higher than in control subjects. Conclusions: Despite inspiratory muscle weakness and a V’E similar to that in normal subjects, central drive is increased in patients with chronic liver disease. The increase in ventilatory drive is related to smaller lung volumes and weakly associated with increase in respiratory elastance. Findings confirm that P0.1 is a reliable measure of central drive and is an approach that can be used in the evaluation of control of ventilation in patients with chronic liver disease.

Home-Nebulized Inhaled Glucocorticoid Therapy in Pediatric Respiratory Diseases

Objective:To evaluate the therapeutic effect of home-nebulized inhaled glucocorticoid therapy in pediatric respiratory diseases.Methods:60 cases of children with respiratory diseases admitted between October 2022 and October 2023 were selected as study subjects and randomly divided into the control group and the observation group,30 cases each.The control group was provided with conventional treatment only,while the observation group was provided with home-nebulized inhalation glucocorticosteroid treatment,and the treatment effects,clinical symptom relief time,disease recurrence rate,and treatment satisfaction of the children’s families were recorded and compared between the two groups.Results:A comparison of the two groups in terms of gender and age showed that the differences were not statistically significant(P>0.05).In terms of clinical efficacy,the total effective rate of the observation group was 90.00%,which was significantly higher than that of the control group of 66.67%(P<0.05).Compared with the control group,the disappearance time of the clinical symptoms of the observed group was significantly shortened(P<0.05).In addition,the satisfaction scores of the families of the children in the observation group were significantly higher than those of the control group(P<0.05).Conclusion:Home-nebulized inhalation glucocorticoid therapy shows significant clinical efficacy in pediatric respiratory diseases,significantly reduces the time of disappearance of clinical symptoms,and improves the satisfaction of patients’families,which provides an effective treatment option for children.

Research Progress on the Association Between Gut Microbiota and Respiratory System Diseases

This paper aims to review the association between gut microbiota and respiratory system diseases, and explore their potential mechanisms and clinical significance. Gut microbiota, as an important microbial ecosystem in the human body, has profound effects on host health. Recent studies have shown that the imbalance of gut microbiota is closely related to the occurrence and development of respiratory system diseases, including asthma, chronic obstructive pulmonary disease (COPD), and pneumonia. We comprehensively analyzed the current research progress and found that gut microbiota may affect respiratory system diseases through various pathways, including immune regulation, inflammatory responses, and airway mucus secretion. Additionally, environmental factors, lifestyle, and dietary habits are also closely related to gut microbiota and respiratory system health. Understanding the relationship between gut microbiota and respiratory system diseases not only helps to reveal the mechanisms of disease occurrence but also provides a theoretical basis for the development of new treatment strategies. Future research should focus on exploring the types and functions of gut microbiota, conducting clinical trials based on this, investigating the effects of gut microbiota modulation on the treatment and prevention of respiratory system diseases, and providing new directions for personalized medicine.

Observation on the Effect of Non-Invasive Ventilator Combined with Conventional Therapy in the Treatment of Chronic Obstructive Pulmonary Disease Complicated with Respiratory Failure

Objective:To explore the clinical effect of a non-invasive ventilator combined with conventional therapy in the treatment of patients with chronic obstructive pulmonary disease(COPD)combined with respiratory failure.Methods:68 patients with COPD combined with respiratory failure treated in our hospital from September 2021 to October 2023 were selected as the research subjects.Using the random number table method,they were divided into a control group and an experimental group of 34 cases each.The control group received conventional symptomatic treatment,and the experimental group received non-invasive ventilator treatment based on the control group.The clinical effects,blood gas indicators(partial pressure of carbon dioxide(PaCO_(2)),partial pressure of oxygen(PaO_(2)),arterial oxygen saturation(SaO_(2))),lung function(forced expiratory volume in 1 second(FEV1),forced vital capacity(FVC),6 min walking distance),complications,and inflammatory factor levels(c-reactive protein(CRP),interleukin-6(IL-6),neutrophil-to-lymphocyte ratio(NLR))of the two groups of patients were observed.Results:(1)The clinical efficacy of the patients in the experimental group(33/97.06%)was more significant as compared with the control group(25/73.53%)(P<0.05);(2)After treatment,the clinical efficacy of the two groups of patients in terms of FEV1,FEV1/FVC,6-minute walking distance,PaO_(2)and SaO_(2)all increased in the experimental group as compared to that of the control group(P<0.05);(3)After treatment,the PaCO_(2),CRP,IL-6,and NLR of the two groups of patients decreased,and the decrease in the experimental group was higher than that of the control group(P<0.05);(4)The patients’complication rate in the experimental group(2/5.88%)was lower as compared to that of the control group(9/26.46%)(P<0.05).Conclusion:Non-invasive ventilators combined with conventional therapy achieved good clinical results in treating patients with COPD and respiratory failure.

Analysis of Perioperative Respiratory Care Methods and their Application Value in Children with Congenital Heart Disease

Objective:To analyze the perioperative respiratory care methods and application value in children with congenital heart disease.Methods:60 children with congenital heart disease(treated from January 2021 to October 2023)were screened and divided into two groups randomly.Each group consisted of 30 cases.The perioperative routine was used in the control group.The observation group underwent the perioperative routine along with better respiratory care.Oxygenation indicators,surgical complications,and family satisfaction levels of the groups were compared.Results:There was no significant difference in the oxygenation index between the two groups of children at admission(P>0.05).At discharge,the oxygenation indicators in the observation group were better than those of the control group,and the incidence of surgical complications was lower than that of the control group.The total satisfaction of family members in the observation group was higher than that of the control group(P<0.05).Conclusion:During the perioperative period for children with congenital heart disease,the implementation of respiratory care,which mainly involves symptomatic care,catheter care,sputum suction care,etc.,can actively improve the oxygenation indicators,reduce surgical complications,and promote faster and better recovery,of children with congenital heart disease.

Analysis of the Effect of Respiratory Rehabilitation Nursing on the Quality of Life of Patients with Chronic Obstructive Pulmonary Disease

Objective:To understand the impact of respiratory rehabilitation nursing on the quality of life of patients with chronic obstructive pulmonary disease(COPD),and to provide a theoretical basis for better clinical implementation of this nursing measure.Methods:68 COPD patients admitted from September 2022 to July 2023 were selected to determine the type of COPD(mild,moderate,severe)based on clinical manifestations and laboratory test results,and were divided into a study group(42 cases)and a control group(26 cases),with the control group adopting the conventional treatment plan,and the patients in the study group receiving individualized respiratory rehabilitation nursing care.The patients’respiratory function and quality of life after treatment are observed.Results:The total score of the study group(65.71±12.02)was significantly higher than that of the control group(52.73±11.54),and the difference was statistically significant(P<0.05);in terms of pulmonary function,the results of pulmonary function tests of the two groups of patients were in the normal range after treatment,and the study group was slightly better than that of the control group,and the difference was statistically significant(P<0.05);the score of the study group in terms of exercise endurance was significantly higher than that of the control group,and the difference was statistically significant(P<0.05).Conclusion:Respiratory rehabilitation nursing can effectively improve the quality of life of COPD patients,and is worthy of popularization and application.

Clinical Study on Respiratory Medicine Treatment of Chronic Obstructive Pulmonary Disease Combined with Respiratory Failure

Objective:To explore the respiratory medicine treatment methods for treating chronic obstructive pulmonary disease(COPD)combined with respiratory failure.Methods:70 cases of COPD patients with combined respiratory failure admitted to our hospital from January 2021 to January 2023 were selected as the study subjects,and randomly divided into the control group and the experimental group,each with 35 cases.The control group received only conventional treatment,and the experimental group received non-invasive positive pressure ventilation,and the treatment effects and changes in the levels of IL-18,hs-CRP,and CES2 inflammatory factors were observed and evaluated in the two groups.Results:There was no significant difference between the general data of the two groups(P>0.05);after treatment,the total effective rate of clinical efficacy of the observation group(91.43%)was significantly higher than that of the control group(71.43%),and the difference showed a significant correlation(P<0.05);after treatment,the level of inflammatory factor of the observation group was significantly reduced compared with that of the control group,and the difference showed a highly significant correlation(P<0.001).Conclusion:The non-invasive positive pressure ventilation treatment program significantly improves the therapeutic effect,effectively controls the level of inflammatory factors,and improves the health status of patients when dealing with patients with chronic obstructive pulmonary disease accompanied by respiratory failure,showing a good clinical application prospect.

A Diagnostic Approach to Diseases in Pig's Respiratory System Based upon SVM Binary Tree

[Objective]To study a diagnostic approach to diseases in pig＇s respiratory system based upon SVM binary tree. [Method] First with the help of clustering theory,the degree of separation based upon the characteristics of diseases is defined. Each time the type of highest degree of separation is isolated to get a decision tree with smaller accumulated errors and SVM binary tree is applied in the diagnostic experiment of four common respiratory diseases. [Result] The method is practicable and can be applied in the diagnosis of pig＇s respiratory diseases at the early stage. [Conclusion] It provides references to the healthy development of pig husbandry in China and increases in breeders＇ incomes.

Effect of exposure to ambient PM2.5 pollution on the risk of respiratory tract diseases： a meta-analysis of cohort studies

The International Agency for Research on Cancer and the World Health Organization have designated airborne particulates, including particulates of median aerodynamic diameter 〈 2.5 gm （PM2.5）, as Group 1 carcinogens. It has not been determined, however, whether exposure to ambient PM2.5 is associated with an increase in respiratory related diseases. This meta-analysis assessed the association between exposure to ambient fine particulate matter （PM2.5） and the risk of respiratory tract diseases, using relevant articles extracted from PubMed, Web of Science, and Embase. In results, of the 1,126 articles originally identified, 35 （3.1%） were included in this meta-analysis. PM2.5 was found to be associated with respiratory tract diseases. After subdivision by age group, respiratory tract disease, and continent, PM2.5 was strongly associated with respiratory tract diseases in children, in persons with cough, lower respiratory illness, and wheezing, and in individuals from North America, Europe, and Asia. The risk of respiratory tract diseases was greater for exposure to traffic-related than non-traffic-related air pollution. In children, the pooled relative risk （RR） represented significant increases in wheezing （8.2%）, cough （7.5%）, and lower respiratory illness （15.3%）. The pooled RRs in children were 1.091 （95%CI： 1.049, 1.135） for exposure to 〈 25 gg/m3 PM2.5, and 1.126 （95%CI： 1.067, l. 190） for exposure to 〉 25 gg/m3 PM2.5. In conclusion, exposure to ambient PM2.5 was significantly associated with the development of respiratory tract diseases, especially in children exposed to high concentrations of PM2.5.

Fear can be more harmful than the severe acute respiratory syndrome coronavirus 2 in controlling the corona virus disease 2019 epidemic

The current corona virus disease 2019 outbreak caused by severe acute respiratory syndrome coronavirus 2 started in Wuhan,China in December 2019 and has put the world on alert.To safeguard Chinese citizens and to strengthen global health security,China has made great efforts to control the epidemic.Many in the global community have joined China to limit the epidemic.However,discrimination and prejudice driven by fear or misinformation have been flowing globally,superseding evidence and jeopardizing the anti-severe acute respiratory syndrome coronavirus 2 efforts.We analyze this phenomenon and its underlying causes and suggest practical solutions.

Heart and lung, a dangerous liaison-Tako-tsubo cardiomyopathy and respiratory diseases: A systematic review

AIM: To investigate the possible association between Tako-tsubo cardiomyopathy(TTC)-a reversible clini-cal condition mimicking an acute myocardial infarction characterized by multifactorial pathophysiologic mecha-nisms- and respiratory system diseases. METHODS: We systematically searched PubMed and EMBASE medical information sources, to identify the different triggering causes, limiting our search to ar-ticles in English. The search keywords were: "tako-tsubo cardiomyopathy", "takotsubo", "takotsubo cardiomyopa-thy", "broken heart syndrome", "stress-induced cardio-myopathy", "apical ballooning syndrome", and "ampulla cardiomyopathy in combination with respiratory dis-eases, lung, pulmonary disease. For each kind of dis-ease, we registered: author, year and country of study, patient sex, age, concurring situation, and outcome. RESULTS: Out of a total of 1725 articles found, we se-lected 37 papers reporting a total of 38 patients. As ex-pected, most patients were women(81.6%), mean age was 65 ± 10 years. Outcome was favorable in 100% of cases, and all the patients have been discharged un-eventfully in a few days. CONCLUSION: An association between respiratory diseases and TTC is likely to exist. Patients with severe respiratory diseases, due to the high dosages of β2-agonists used or to the need of invasive procedures, are highly exposed to the risk of developing TTC.

Helicobacter pylori infection and respiratory diseases:a review

In the past few years,a variety of extradigestive disorders, including cardiovascular,skin,rheumatic and liver diseases, have been associated with Helicobacter pylori(H.pylori) infection.The activation of inflammatory mediators by H.pylori seems to be the pathogenetic mechanism underlying the observed associations.The present review summarizes the current literature,including our own studies,concerning the association between H.pyloriinfection and respiratory diseases. A small number of epidemiological and serologic,case- control studies suggest that H.pylori infection may be associated with the development of chronic bronchitis.A frequent coexistence of pulmonary tuberculosis and H.pylori infection has also been found.Moreover,recent studies have shown an increased H.pyloriseroprevalence in patients with bronchiectasis and in those with lung cancer.On the other hand,bronchial asthma seems not to be related with H.pylori infection. All associations between H.pylori infection and respiratory diseases are primarily based on case-control studies, concerning relatively small numbers of patients.Moreover, there is a lack of studies focused on the pathogenetic link between respiratory diseases and H.pylori infection. Therefore,we believe that larger studies should be undertaken to confirm the observed results and to clarify the underlying pathogenetic mechanisms.

Ultrasonographic study of postcibal gastro-esophageal reflux and gastric emptying in infants with recurrent respiratory disease

AIM: To check the utility of postcibal ultrasonography for the evaluation of reflux in relation to gastric emptying in infants with recurrent respiratory symptoms and to link imaging with clinical data.METHODS: Esophageal reflux (hyperechoic retrograde filling) and gastric emptying (antral areas) were quantified before and after ingestion of a standard formula in 35 untreated infants (13 with chronic cough,22 with recurrent bronchitis) and in 31 controls.RESULTS: The prevalence of abnormal (≥8 episodes)postcibal refluxes was 74% in patients and 3% in controls. Number, duration of the longest episode and extent of refluxes were significantly higher in patients compared to controls. Number of refluxes was higher in patients with symptomatic refluxes than in those without.Infants with recurrent bronchitis had more refluxes than those with chronic cough and controls. Extent and timing of gastric emptying were similar in patients and controls.CONCLUSION: Esophageal ultrasonography is a useful and physiological test in infants with recurrent respiratory diseases, which have a high prevalence of abnormal postcibal esophageal reflux and a gastric emptying similar to that of normal controls. Esophageal reflux is more severe in subjects with recurrent bronchitis than in those with chronic cough.