Dysfunctional Breathing in Children and Adults With Asthma

Dysfunctional Breathing in Children: A Literature Review

Dysfunctional breathing (DB) describes a respiratory condition that is mainly characterized by abnormal breathing patterns, affecting both children and adults, often leading to intermittent or chronic complaints and influencing physiological, psychological, and social aspects. Some symptoms include breathlessness; dizziness; palpitations; and anxiety, while its classification lies in breathing pattern disorders and upper airway involvement. Its prevalence among the pediatric population varies with a female overrepresentation, while the existence of comorbidities in DB, such as asthma, gastro-esophageal reflux, nasal diseases, and anxiety/depression, frequently leads to misdiagnosis or underdiagnosis and complicates therapeutic approaches. The basic diagnostic tools involve a detailed history, physical examination, and procedures such as structured light plethysmography, cardiopulmonary exercise testing, and laryngoscopy when a laryngeal obstruction is present. The management of DB presumes a multidimensional approach encompassing breathing retraining, disease-specific advice through speech and language therapy in the presence of laryngeal obstruction, psychotherapy for fostering self-efficacy, and surgical therapy in a structural abnormality. The current review was developed to provide a summary of classifications of DB and epidemiological data concerning the pediatric population, comorbidities, diagnostic tools, and therapeutic approaches to enhance the comprehension and management of DB in children.

Pediatric asthma comorbidities: Global impact and unmet needs

Real-world data on the range and impact of comorbid health conditions that affect pediatric asthma are scant, especially from developing countries. Lack of data hinders effective diagnosis, treatment, and overall management of these complex cases. We, hereby, describe the common pediatric asthma comorbid conditions in terms of evidence for association, potential mechanisms of impact on asthma control, and treatment benefit. Obesity, upper airway allergies, dysfunctional breathing, multiple sensitizations, depressive disorders, food allergy, and gastro-esophageal reflux are common associations with difficult-to-treat asthma. On the other hand, asthma symptoms and/or management may negatively impact the well-being of children through drug adverse effects, worsening of anaphylaxis symptoms, and disturbing mental health. Awareness of these ailments may be crucial for designing the optimum care for each asthmatic child individually and may ultimately improve the quality of life of patients and their families. A multidisciplinary team of physicians is required to identify and manage such comorbidities aiming to mitigate the over-use of asthma pharmacotherapy. Asthma research should target relevant real-world difficulties encountered at clinical practice and focus on interventions that would mitigate the impact of such comorbidities. Finally, policymakers and global healthcare organizations are urged to recognize pediatric asthma control as a healthcare priority and allocate resources for research and clinical interventions. In other words, global asthma control needs support by compassionate scientific partnership.

Puzzled by dysfunctional breathing disorder(s)? Consider the Bayesian brain hypothesis!

There is currently growing clinical concern regarding dysfunctional breathing disorder(s) (DBD), an umbrella term for a set of multidimensional clinical conditions that are characterized by altered breathing pattern associated with a variety of intermittent or chronic symptoms, notably dyspnea, in the absence or in excess of, organic disease. However, several aspects of DBD remain poorly understood and/or open to debate, especially the inconsistent relationship between the array of experienced symptoms and their supposedly underlying mechanisms. This may be partly due to a more general problem, i.e., the prevailing way we conceptualize symptoms. In the present article, after a brief review of the different aspects of DBD from the current perspective, I submit a call for considering DBD under the innovating perspective of the Bayesian brain hypothesis, i.e., a potent and novel model that fundamentally changes our views on symptom perception.

Expanded central role of the respiratory physiotherapists in the community setting

The development of community hubs through the Slaintecare initiative will rely on respiratory physiotherapists and clinical nurse specialists for the management of chronic respiratory diseases. The role of the respiratory physiotherapist has evolved dramatically over the last decade. We review the increasing scope of practice of the physiotherapist and the evidence base for same. We pay particular attention to the role of the physiotherapist in areas such as pulmonary rehabilitation, sputum clearance, neuromuscular disease, chronic respiratory failure, ambulatory oxygen assessments and dysfunctional breathing. We give an in depth review of sputum clearance techniques. We also address areas of potential future expansion for the role of the physiotherapist such as prescription and initiation of non-invasive ventilation.

Exercise induced laryngeal obstruction (EILO) in children and young people: Approaches to assessment and management

Exercise Induced Laryngeal Obstruction (EILO) is characterised by breathlessness, cough and/or noisy breathing particularly during high intensity exercise. EILO is a subcategory of inducible laryngeal obstruction where exercise is the trigger that provokes inappropriate transient glottic or supraglottic narrowing. It is a common condition affecting 5.7-7.5% of the general population and is a key differential diagnosis for young athletes presenting with exercise related dyspnoea where prevalence rates go as high as 34%. Although the condition has been recognised for a long time, little attention, and awareness of the condition results in many young people dropping out of sporting participation due to troublesome symptoms. With evolving understanding of the condition, diagnostic tests and interventions, this review looks to present the current available evidence and best practice when managing young people with EILO.

Physiotherapy assessment of breathing pattern disorder: a qualitative evaluation

OBJECTIVES

To explore physiotherapists' opinions of physiotherapy assessment of Breathing Pattern Disorder (BPD).

METHODS

Qualitative study using focus groups (FGs) with reflexive thematic analysis and survey methods. The survey was distributed via social media and email to UK specialist physiotherapy interest groups. Two FGs, conducted in different settings, included physiotherapists based in hospital outpatients/community, private practice and higher education.

RESULTS

One-hundred-and-three physiotherapists completed the survey. Respondents identified a lack of consensus in how to define BPD, but some agreement in the components to include in assessment. Fifteen physiotherapists participated in the FGs. Three themes emerged from FG discussions: (1) nomenclature and language of breathing, (2) BPD and breathlessness and (3) The value of assessment of breathlessness.

CONCLUSION

The inconsistent nomenclature of dysfunctional breathing pattern impacts assessment, management and understanding of the diagnosis. Clarity in diagnosis, informing consistency in assessment, is fundamental to improving recognition and treatment of BPD. The findings are useful in the planning of education, training, future research and guideline development in BPD assessment.

Dysfunctional breathing and its impact on asthma control in children and adolescents

BACKGROUND

Dysfunctional breathing (DB) has been shown to negatively affect asthma control in adults, but for children and adolescents, the knowledge is scarce. DB is among others characterized by dyspnea and hyperventilation. The Nijmegen Questionnaire (NQ) is often used as a marker for DB. We conducted a cross-sectional survey to estimate the prevalence of DB in patients with asthma in a pediatric outpatient clinic and to determine the impact of DB on asthma control.

METHODS

Patients between 10 and 17 years were invited to complete the NQ and the Asthma Control Questionnaire (ACQ) and report the use of beta2 agonist (β2). Spirometry data and prescribed asthma medications were noted from the patient record.

RESULTS

Three hundred and sixty-three patients (180 boys) completed the survey. Sixty-seven patients (18%) scored ≥23 points in the NQ predicting DB. The DB group was older (median (range)) 15.6 (10.5-17.9) vs. 13.7 (10.0-17.9) years) (p < .01), and girls were overrepresented (84%) (p < .01). FEV1% exp. was higher in the DB group (mean (SD)) (89.4 (9.0) vs. 85.7 (11.8)) (p < .02). ACQ score (median (range)) (2.0 (0-4) vs. 0.6 (0-3.4)) (p < .01) and the use of β2 (median (range)) (2 (0-56) vs. 0 (0-20) puffs/week) (p < .01) were higher. Inhaled corticosteroid dose (mean (SD) (416 (160) vs. 420 (150) mcg) and the use of a second controller were equal between the groups.

CONCLUSION

Dysfunctional breathing was a frequent comorbidity, especially in adolescent girls. DB correlated with poorer asthma control and higher use of β2 and may be an important cofactor in difficult-to-treat asthma.

Respiratory comorbidities in severe asthma: focus on the pediatric age

INTRODUCTION

Asthma comorbidities are a frequent cause of adverse outcomes, such as poor asthma control, frequent asthma attacks, reduced quality of life, and higher healthcare costs. Comorbidities are well-known treatable traits whose proper management can help achieve optimal asthma control. Although multimorbidity is frequent among asthmatics, comorbidities are still a potential cause of misdiagnosis and under or over treatments, and little is known about their impact on severe pediatric asthma.

AREAS COVERED

We provided a comprehensive, 5-year updated review focusing on the main respiratory comorbidities in severe asthma, particularly in epidemiology, pathogenesis, and current and future therapies.

EXPERT OPINION

Respiratory comorbidities have unique characteristics in childhood. Their management must be multidisciplinary, age-specific, and integrated. Further longitudinal studies are needed to understand better the mutual interrelation and synergistic effect between asthma and its respiratory comorbidities, the identification of common, treatable risk factors leading to potential asthma prevention, the effectiveness of actual and future target-therapies, and the correlation between long-lasting respiratory comorbidities and poor lung function trajectories.

Planning a digital intervention for adolescents with asthma (BREATHE4T): A theory-, evidence- and Person-Based Approach to identify key behavioural issues

OBJECTIVES

To describe a transparent approach to planning a digital intervention for adolescents to self-manage their asthma using breathing retraining (BRT), based on an existing, effective adult intervention (BREATHE).

METHODS

A theory-, evidence-, and Person-Based Approach was used to maximise the effectiveness and persuasiveness of the intervention. A scoping review and semistructured interviews with target intervention users (N = 18, adolescents aged 12-17 years with asthma and parents) were carried out to explore user perspectives, barriers, and facilitators towards the intended behaviours and potential intervention features. The combined evidence was used alongside and to inform theory-based activities and enabled iterative planning of the intervention.

RESULTS

The scoping review identified themes relating to user-specific self-management issues, content, education, training needs, and features for a digital intervention. Interviews elicited potential barriers to intended behaviours such as the anticipated embarrassment of using BRT and concerns around remaining calm. Facilitators included BRT delivered by adolescents who share experiences of asthma and information for performing exercises discreetly. Relevant theoretical frameworks ensured that appropriate psychological constructs were targeted. A behavioural analysis identified six intervention functions and thirty behaviour change techniques. Logic modelling mapped the programme theory and mechanisms, which aims to improve adolescent asthma-related quality of life.

CONCLUSIONS

This study gives a transparent insight into the approach followed to plan a self-guided BRT intervention for adolescents and has led to identification of key behavioural issues, enabling relevant intervention content to be chosen. Insight has been given into adolescent perceptions of BRT, which facilitated development of the prototype intervention.

Multimorbidity in Difficult Asthma: The Need for Personalised and Non-Pharmacological Approaches to Address a Difficult Breathing Syndrome

Three to ten percent of people living with asthma have difficult-to-treat asthma that remains poorly controlled despite maximum levels of guideline-based pharmacotherapy. This may result from a combination of multiple adverse health issues including aggravating comorbidities, inadequate treatment, suboptimal inhaler technique and/or poor adherence that may individually or collectively contribute to poor asthma control. Many of these are potentially "treatable traits" that can be pulmonary, extrapulmonary, behavioural or environmental factors. Whilst evidence-based guidelines lead clinicians in pharmacological treatment of pulmonary and many extrapulmonary traits, multiple comorbidities increase the burden of polypharmacy for the patient with asthma. Many of the treatable traits can be addressed with non-pharmacological approaches. In the current healthcare model, these are delivered by separate and often disjointed specialist services. This leaves the patients feeling lost in a fragmented healthcare system where clinical outcomes remain suboptimal even with the best current practice applied in each discipline. Our review aims to address this challenge calling for a paradigm change to conceptualise difficult-to-treat asthma as a multimorbid condition of a "Difficult Breathing Syndrome" that consequently needs a holistic personalised care attitude by combining pharmacotherapy with the non-pharmacological approaches. Therefore, we propose a roadmap for an evidence-based multi-disciplinary stepped care model to deliver this.

Psychological and Sociocultural Determinants in Childhood Asthma Disease: Impact on Quality of Life

Asthma is the most common chronic disease in childhood. The presence of this pathology in children leads to the appearance of different alterations (physical, psychological, social, etc.). Due to their high influence, the aim of this study is to understand these psychological and sociocultural determinants and their impact on the quality of life of asthmatic children. In order to determine the influence of these determinants on quality of life, a narrative review of 48 articles collected in different databases was carried out. Emotions are the most powerful precursor to producing an asthmatic attack. Anxiety and depression are the pathologies that appear frequently associated with childhood asthma, together with Attention-Deficit/Hyperactivity Disorder. In addition, the personality of these children seems to be characterized by shyness and impulsivity, although exceptionally it has been associated with psychopathic behaviors, aggressiveness, and cases of psychosis. School performance is impaired and bullying occurs more frequently. Likewise, dysfunctional family relationships and lower socioeconomic status have a negative impact on the severity and management of asthma. In short, the quality of life of asthmatic children is lower due to the presence of the aforementioned psychological and sociocultural determinants.

Role of Breathing Exercises in Asthma-Yoga and Pranayama

Asthma is a chronic airway inflammatory disease that results from a complex interplay of genetic, environmental, and lifestyle factors. There is no cure for asthma, and the management is usually as per published guidelines. As in many chronic diseases conditions, various alternative or complimentary therapies have been tried. Of these, yoga and pranayama have gained wider attention in recent years. While the term yoga is a complex term encompassing eight limbs as per Patamjai in the yoga sutras, in simple terms, yoga is described as a combination of 'asana' (physical exercises) and 'pranayama' (breathing exercise). The term "asthma" has been derived from the Greek word "panting,", which indicates a rapid and shallow breathing. The main aim of yoga and pranayama in asthma is to synchronize and control breathing, thus decreasing hyperventilation. Besides this, they also decrease the stress/strain/anxiety, change in behavior, boost immunity, and improve strength/endurance of respiratory muscles that are helpful in any subject with asthma. There have been a good number of studies including clinical trials in children with asthma that have found some beneficial effects. In the present review, the physiology of yoga and pranayama, rationale for their use in children with asthma along with a summary of various studies conducted till date, have been discussed. These are followed by recommendations regarding their incorporation in the standard of care of children with asthma.

Do not forget asthma comorbidities in pediatric severe asthma!

Asthma is the most common chronic respiratory disease in childhood. The long-term goals in managing asthma aim to control symptoms and prevent exacerbations, as well as to reduce side effects of therapy and mortality disease-related. Most of patients have mild to moderate asthma and respond well to standard therapies. However, a minor proportion of children with asthma has severe disease that remains uncontrolled despite optimal adherence to prescribed therapy and treatment of contributory factors, including trigger exposures and comorbidities, which can mimic or worsen asthma and contribute to exacerbations and poor quality of life. Evaluation of comorbidities is fundamental to optimize the management of the disease in a subgroup of patients with poor responder asthma. The overall aim of this article is to describe characteristics of main pediatric severe asthma comorbidities reported in literature, giving clinicians tools to recognize and manage properly these conditions.

Prevalence of hyperventilation in patients with asthma

OBJECTIVE

Asthma is frequently accompanied by dysfunctional breathing of which hyperventilation has been recognized as a subtype. The prevalence of hyperventilation in stable asthma has been scantily studied using blood gas analysis. Hence, a reliable estimate of its prevalence is lacking. It is unknown whether the Nijmegen Questionnaire (NQ) is a useful screening tool for hyperventilation in asthma. Therefore, the primary aim of this study was to determine the prevalence of hyperventilation in a large sample of patients with asthma in a stable state of disease. Secondary aims were to compare the clinical characteristics between patients with and without hyperventilation, and, to examine the concurrent validity of the NQ to detect hypocapnia in patients with asthma.

METHODS

A real-world, observational, multicenter study was conducted. Capillary blood gas analysis was performed in adults with a confirmed diagnosis of stable asthma. A subset of patients completed the NQ.

RESULTS

A blood gas analysis was obtained in 1006 patients. In 17% of the patients an acute hyperventilation was found, and in another 23% a chronic hyperventilation was uncovered. Patients with a chronic hyperventilation blood gas were more often female, were younger and had a better spirometric outcomes. The NQ appeared not to correlate with PCO2.

CONCLUSION

Hyperventilation is common in patients with stable asthma. Chronic hyperventilation is more often found in females of younger age and with the best spirometric outcomes compared to patients without hyperventilation. The NQ is not a suitable screening tool for the presence of hyperventilation in stable asthmatics.

Comparative analysis between available challenge tests in the hyperventilation syndrome

BACKGROUND

The hyperventilation syndrome (HVS) is characterized by somatic/ psychological symptoms due to sustained hypocapnia and respiratory alkalosis without any organic disease.

OBJECTIVE

The purpose of this study was to compare ventilatory parameters and symptoms reproducibility during the hyperventilation provocation test (HVPT) and cardiopulmonary exercise test (CPET) as diagnostic tools in patients with HVS, and to identify the most frequent etiologies of the HVS by a systematic assessment.

METHODS

After exclusion of organic causes, 59 patients with HVS according to Nijmegen's questionnaire (NQ) score ≥23 with associated hypocapnia (PaCO₂/PET_CO2<35 mm Hg) were studied.

RESULTS

The most frequent comorbidities of HVS were anxiety and asthma (respectively 95% and 73% of patients). All patients described ≥3 symptoms of NQ during the HVPT vs 14% of patients during the CPET (p<0.01). For similar maximal ventilation (61 L/min during HVPT vs 60 L/min during CPET), the median level of PET_CO2 decreased from 30 mmHg at baseline to 15 mmHg during hyperventilation and increased from 31 mmHg at baseline to 34 mmHg at peak exercise (all p<0.01). No significant difference for the ventilatory parameters was found between patients with HVS (n = 16) and patients with HVS + asthma (n = 43).

CONCLUSIONS

In term of symptoms reproducibility, HVPT is a better diagnostic tool than CPET for HVS. An important proportion of patients with HVS has an atypical asthma previously misdiagnosed. The exercise-induced hyperventilation did not induce abnormal reduction in PET_CO2, suggesting that the exercise could be a therapeutic tool in HVS.

The impact of comorbidities on severe asthma

PURPOSE OF REVIEW

Severe asthma is often associated with numerous comorbidities that complicate disease management and affect patient's outcomes. They contribute to poor disease control and mimic asthma symptoms. Although some comorbidities such as obstructive sleep apnea, bronchiectasis, and chronic obstructive pulmonary disease are generally well recognized, many other may remain undiagnosed but may be detected in an expert specialist setting. The management of comorbidities seems to improve asthma outcomes, and optimizes therapy by avoiding overtreatment. The present review provides recent knowledge regarding the most common comorbidities which are associated with severe asthma.

RECENT FINDINGS

Comorbidities are more prevalent in severe asthma than in mild-to-moderate disease or in the general population. They can be grouped into two large domains: the pulmonary domain and the extrapulmonary domain. Pulmonary comorbidities include upper respiratory tract disorders (obstructive sleep apnea, allergic and nonallergic rhinitis, chronic rhinosinusitis, nasal polyposis) and middle/lower respiratory tract disorders (chronic obstructive pulmonary disease, allergic bronchopulmonary aspergillosis and fungal sensitization, bronchiectasis, dysfunctional breathing). Extrapulmonary comorbidities include anxiety, depression, gastro-esophageal reflux disease, obesity, cardiovascular, and metabolic diseases.

SUMMARY

The identification of comorbidities via multidimensional approach is needed to initiate appropriate multidisciplinary management of patients with severe asthma.

Clinical characteristics and hemodynamic responses to head-up tilt test in children and adolescents with unexplained sighing

OBJECTIVE

Sighing is a common symptom in children and adolescents. In this study, we explored the clinical characteristics and hemodynamic responses to head-up tilt test (HUTT) in children and adolescents with unexplained sighing.

METHODS

One hundred ninety-two children and adolescents complaining of unexplained sighing were enrolled as study group after excluding chest wall, lung, heart diseases, and psychogenic disorders. Sixty-nine healthy individuals were enrolled as control group. All the subjects underwent HUTT.

RESULTS

Nitroglycerin-stimulated HUTT positive rate was higher in the study group than the control group (24.0% vs 10.1%, P = 0.014). In total, 32.3% of patients with sighing had positive responses to HUTT, which was higher than that of healthy individuals (32.3% vs 15.9%, P = 0.009). Among 62 cases with positive responses to HUTT in the study group, 48 cases were vasoinhibitory type vasovagal syncope (VVS), 5 cases were mixed type VVS, 3 cases were cardioinhibitory type VVS, 5 cases were postural tachycardia syndrome, and one case was orthostatic hypertension. Sighing patients with positive responses to HUTT had female dominance (54.8% vs39.2%, P = 0.045), older mean age (9.6 ± 2.8 vs 8.1 ± 2.7 years old, P = 0.001), higher basic systolic blood pressure (104.8 ± 10.4 vs 101.1 ± 9.9 mmHg, P = 0.019), and higher diastolic blood pressure (66.0 ± 7.5 vs 62.9 ± 9.2 mmHg, P = 0.021) compared with those of negative responses. CONCLUSIONS : Nearly one-third of children and adolescents with unexplained sighing had positive responses to HUTT, demonstrating that sighing was related to dysfunction of the autonomic nervous system. Elder female patients with higher systolic and diastolic blood pressure were more likely to have positive responses to HUTT.

Diagnosis in children with exercise-induced respiratory symptoms: A multi-center study

OBJECTIVE

Exercise-induced respiratory symptoms (EIS) are common in childhood and reflect different diseases that can be difficult to diagnose. In children referred to respiratory outpatient clinics for EIS, we compared the diagnosis proposed by the primary care physician with the final diagnosis from the outpatient clinic and described diagnostic tests and treatments.

DESIGN

An observational study of respiratory outpatients aged 0-16 years nested in the Swiss Paediatric Airway Cohort (SPAC).

PATIENTS

We included children with EIS as the main reason for referral. Information about diagnostic investigations, final diagnosis, and treatment prescribed came from outpatient records. We included 214 children (mean age 12 years, range 2-17, 54% males) referred for EIS.

RESULTS

The final diagnosis was asthma in 115 (54%), extrathoracic dysfunctional breathing (DB) in 35 (16%), thoracic DB in 22 (10%), asthma plus DB in 23 (11%), insufficient fitness in 10 (5%), chronic cough in 6 (3%), and other diagnoses in 3 (1%). Final diagnosis differed from referral diagnosis in 115 (54%, 95%-CI 46%-60%). Spirometry, body plethysmography, and exhaled nitric oxide were performed in almost all, exercise-challenge tests in a third, and laryngoscopy in none. 91% of the children with a final diagnosis of asthma were prescribed inhaled medication and 50% of children with DB were referred to physiotherapy.

CONCLUSIONS

Diagnosis given at the outpatient clinic often differed from the diagnosis proposed by the referring physician. Diagnostic evaluations, management, and follow-up differed between clinics and diagnostic groups highlighting the need for evidence-based diagnostic guidelines and harmonized procedures for children seen for EIS.

The Need for Testing-The Exercise Challenge Test to Disentangle Causes of Childhood Exertional Dyspnea

Exertional dyspnea is a common symptom in childhood which can induce avoidance of physical activity, aggravating the original symptom. Common causes of exertional dyspnea are exercise induced bronchoconstriction (EIB), dysfunctional breathing, physical deconditioning and the sensation of dyspnea when reaching the physiological limit. These causes frequently coexist, trigger one another and have overlapping symptoms, which can impede diagnoses and treatment. In the majority of children with exertional dyspnea, EIB is not the cause of symptoms, and in asthmatic children it is often not the only cause. An exercise challenge test (ECT) is a highly specific tool to diagnose EIB and asthma in children. Sensitivity can be increased by simulating real-life environmental circumstances where symptoms occur, such as environmental factors and exercise modality. An ECT reflects daily life symptoms and impairment, and can in an enjoyable way disentangle common causes of exertional dyspnea.

Reported Symptoms Differentiate Diagnoses in Children with Exercise-Induced Respiratory Problems: Findings from the Swiss Paediatric Airway Cohort (SPAC)

BACKGROUND

Exercise-induced breathing problems with similar clinical presentations can have different etiologies. This makes distinguishing common diagnoses such as asthma, extrathoracic and thoracic dysfunctional breathing (DB), insufficient fitness, and chronic cough difficult.

OBJECTIVE

We studied which parent-reported, exercise-induced symptoms can help distinguish diagnoses in children seen in respiratory outpatient clinics.

METHODS

This study was nested in the Swiss Paediatric Airway Cohort, an observational study of children aged 0 to 17 years referred to pediatric respiratory outpatient clinics in Switzerland. We studied children aged 6 to 17 years and compared information on exercise-induced symptoms from parent-completed questionnaires between children with different diagnoses. We used multinomial regression to analyze whether parent-reported symptoms differed between diagnoses (asthma as base).

RESULTS

Among 1109 children, exercise-induced symptoms were reported for 732 (66%) (mean age: 11 years, 318 of 732 [43%] female). Among the symptoms, dyspnea best distinguished thoracic DB (relative risk ratio [RRR]: 5.4, 95% confidence interval [CI]: 1.3-22) from asthma. Among exercise triggers, swimming best distinguished thoracic DB (RRR: 2.4, 95% CI: 1.3-6.2) and asthma plus DB (RRR: 1.8, 95% CI: 0.9-3.4) from asthma only. Late onset of symptoms was less common for extrathoracic DB (RRR: 0.1, 95% CI: 0.03-0.5) and thoracic DB (RRR: 0.4, 95% CI: 0.1-1.2) compared with asthma. Localization of dyspnea (throat vs chest) differed between extrathoracic DB (RRR: 2.3, 95% CI: 0.9-5.8) and asthma. Reported respiration phase (inspiration or expiration) did not help distinguish diagnoses.

CONCLUSION

Parent-reported symptoms help distinguish different diagnoses in children with exercise-induced symptoms. This highlights the importance of physicians obtaining detailed patient histories.

Breathing pattern disorders (dysfunctional breathing) characteristics and outcomes of children and young people attending a secondary care respiratory clinic

METHODS

We retrospectively audited the health records of 18 patients with breathing pattern disorders (BPDs), who were diagnosed in our respiratory clinic (2015-2018), and then referred onto our dysfunctional breathing care pathway to a specialist speech and language therapist.

RESULTS

The age of the patients ranged from 11 to 16 years (median: 14 years, 14 female/4 male patients). Comorbidities included the following: 16 patients had asthma, 2 patients had a tracheoesophageal fistula and esophageal atresia repair, one patient suffered from chronic regional pain syndrome, and one patient had chronic fatigue syndrome. The commonest BPD was induced laryngeal obstruction (ILO) in 16 patients (exercise-induced laryngeal obstruction [EILO] in 15). Other types of BPDs included hyperventilation syndrome in seven patients, psychogenic cough in eight, and dysphonia in one. A single BPD was present in 6 patients (mainly EILO), and two or more BPDs were present in 10 patients. Inducers of BPD symptoms were as follows: exercise in 16 patients, bullying in 3, anxiety in 14, emotions and stress in 11, weather in 3, posture in 1, and odors in 3. Significant school absenteeism was observed in most of the patients (2 weeks to 24 months). Significant delays in diagnosing BPD were noted (range: 1-24 months and median: 6 months). Emergency calls occurred in 14 patients, with one patient presenting with ILO and comorbidity of asthma needing intubation and ventilation. A 1-year follow-up of patients showed that there was a complete resolution of BPD in two patients, 14 had good control of BPD with confidence in ability to control their symptoms, showing improved morbidity, two had no improvement, and one lost to follow-up.

CONCLUSION

It is important to recognize and treat BPD early to limit the significant morbidity that adversely impacts the quality of life.

Circular RNA circHIPK3 modulates the proliferation of airway smooth muscle cells by miR-326/STIM1 axis

AIMS

Emerging findings demonstrate the critical roles of noncoding RNA (ncRNA) in asthma development. Nevertheless, the biological roles of circular RNA (circRNA) in airway remodeling are still elusive. Here, the present research focuses on the regulation of circRNA circHIPK3 in airway smooth muscle cells (ASMCs) proliferation and migration.

MATERIALS AND METHODS

The sequence of circRNA was detected using Sanger sequencing. Cellular phenotypes were detected using CCK-8 assay, transwell and flow cytometer assay. The potential binding of miRNA and downstream and upstream targets was detected using dual-luciferase reporter assay.

KEY FINDINGS

Results showed that circHIPK3 was significantly upregulated in platelet-derived growth factor (PDGF) induced ASMCs. Functional analysis using CCK-8, transwell migration assays and flow cytometry analysis showed that circHIPK3 knockdown repressed proliferation, migration and up-regulated the apoptosis in ASMCs. Mechanistic assays showed that circHIPK3 sponged miR-326 in the cytoplasm, thereby targeting stromal interaction molecule 1 (STIM1) to regulate ASMCs' proliferation, migration and apoptosis.

SIGNIFICANCE

Collectively, the data elucidates that circHIPK3 functions as a regulator in the airway remodeling during the asthma development through miR-326/STIM1 axis, providing a novel insight for the therapeutic target.

Paradoxical Vocal Fold Motion in Difficult Asthma Is Associated with Dysfunctional Breathing and Preserved Lung Function

BACKGROUND

Many patients with difficult asthma also have coexisting vocal cord dysfunction (VCD), evident by paradoxical vocal fold motion (PVFM) on laryngoscopy.

OBJECTIVE

Among patients with difficult asthma, we sought to identify clinical features associated with laryngoscopy-diagnosed PVFM.

METHODS

Consecutive patients with "difficult asthma" referred by respiratory specialists underwent systematic assessment in this observational study. Those with a high clinical suspicion for VCD were referred for laryngoscopy, either at rest or after mannitol provocation. Statistical analyses were performed to identify clinical factors associated with PVFM, and a multivariate logistic regression model was fitted to control for confounders.

RESULTS

Of 169 patients with difficult asthma, 63 (37.3%) had a high clinical probability of VCD. Of 42 who underwent laryngoscopy, 32 had PVFM confirmed. Patients with PVFM more likely had preserved lung function (prebronchodilator forced expiratory ratio 74% ± 11 vs 62% ± 16, P < .001); physiotherapist-confirmed dysfunctional breathing (odds ratio [OR] = 5.52, 95% confidence interval [CI]: 2.4-12.7, P < .001), gastro-oesophageal reflux (OR = 2.6, 95% CI: 1.16-5.8, P = .02), and a lower peripheral eosinophil count (0.09 vs 0.23, P = .004). On multivariate logistic regression, independent predictors for PVFM were dysfunctional breathing (OR = 4.93, 95% CI: 2-12, P < .001) and preserved lung function (OR = 1.07, 95% CI: 1.028-1.106, P < .001).

CONCLUSION

Among specialist-referred patients with difficult asthma, VCD pathogenesis may overlap with dysfunctional breathing but is not associated with severe airflow obstruction. Dysfunctional breathing and preserved lung function may serve as clinical clues for the presence of VCD.

Pediatric Dysfunctional Breathing: Proposed Components, Mechanisms, Diagnosis, and Management

Dysfunctional breathing (DB) is an overarching term describing deviations in the normal biomechanical patterns of breathing which have a significant impact on quality of life, performance and functioning. Whilst it occurs in both children and adults, this article focuses specifically on children. DB can be viewed as having two components; breathing pattern disorder (BPD) and inducible laryngeal obstruction (ILO). They can be considered in isolation, however, are intricately related and often co-exist. When both are suspected, we propose both BPD and ILO be investigated within an all-encompassing multi-disciplinary dysfunctional breathing clinic. The MDT clinic can diagnose DB through expert history taking and a choice of appropriate tests/examinations which may include spirometry, breathing pattern analysis, exercise testing and laryngoscopic examination. Use of the proposed algorithm presented in this article will aid decision making regarding choosing the most appropriate tests and understanding the diagnostic implications of these tests. The most common symptoms of DB are shortness of breath and chest discomfort, often during exercise. Patients with DB typically present with normal spirometry and an altered breathing pattern at rest which is amplified during exercise. In pediatric ILO, abnormalities of the upper airway such as cobblestoning are commonly seen followed by abnormal activity of the upper airway structures provoked by exercise. This may be associated with a varying degree of stridor. The symptoms, however, are often misdiagnosed as asthma and the picture can be further complicated by the common co-presentation of DB and asthma. Associated conditions such as asthma, extra-esophageal reflux, rhinitis, and allergy must be treated appropriately and well controlled before any directed therapy for DB can be started if therapy is to be successful. DB in pediatrics is commonly treated with a course of non-pharmaceutical therapy. The therapy is provided by an experienced physiotherapist, speech and language therapist or psychologist depending on the dominant features of the DB presentation (i.e., BPD or ILO in combination or in isolation) and some patients will benefit from input from more than one of these disciplines. An individualized treatment program based on expert assessment and personalized goals will result in a return to normal function with reoccurrence being rare.

Protocol for a multicentre randomised controlled trial to investigate the effect on asthma-related quality of life from breathing retraining in patients with incomplete asthma control attending specialist care in Denmark

INTRODUCTION AND AIM

Uncontrolled asthma is a global health challenge with substantial impact on quality of life (QoL) and overall healthcare costs. Unrecognised and/or unmanaged comorbidities often contribute to presence of uncontrolled asthma. Abnormalities in breathing pattern are termed dysfunctional breathing and are not only common in asthma but also lead to asthma-like symptoms and reduced QoL, and, in keeping with this, improvement with breathing normalisation. Evidence-based guidelines recommend breathing retraining interventions as an adjuvant treatment in uncontrolled asthma. Physiotherapy-based breathing pattern modification interventions incorporating relaxation have been shown to improve asthma-related QoL in primary care patients with impaired asthma control. Despite anecdotal reports, effectiveness of breathing retraining in patients referred to secondary care with incomplete asthma control has not been formally assessed in a randomised controlled trial (RCT). We aim to investigate the effect of breathing exercises on asthma-related QoL in patients with incomplete asthma control despite specialist care.

METHODS AND ANALYSIS

This two-armed assessor-blinded multicentre RCT will investigate the effect of physiotherapist-delivered breathing retraining on asthma QoL questionnaire (MiniAQLQ) in addition to usual specialist care, recruiting from seven outpatient departments and one specialised clinic representing all regions of Denmark during 2017-2019. We will include 190 consenting adults with incomplete asthma control, defined as Asthma Control Questionnaire 6-item score ≥0.8. Participants will randomly be allocated to either breathing exercise programme in addition to usual care (BrEX +UC) or UC alone. BrEX compiles three physiotherapy sessions and encouragement to perform home exercise daily. Both groups continue usual secondary care management. Primary outcome is between-group difference in MiniAQLQ at 6 months. Secondary outcomes include patient-reported outcome measures, spirometry and accelerometer.

ETHICS AND DISSEMINATION

Ethics Committee, Region Zealand (SJ-552) and Danish Data Protection Agency (REG-55-2016) approved the trial. Results will be reported in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

NCT03127059; Pre-results.