Breathing exercises for dysfunctional breathing/hyperventilation syndrome in adults

Unraveling persistent dyspnea after mild COVID: insights from a case series on hyperventilation provocation tests

Dyspnea is a common yet poorly understood symptom of long COVID, affecting many patients. This brief report examines the role of dysfunctional breathing in persistent dyspnea among patients with mild post-COVID-19 using hyperventilation provocation tests (HVPT). In this case series, six patients with unexplained dyspnea and normal cardiopulmonary function underwent HVPT. Despite normal exercise testing results, all patients exhibited delayed PETCO2 recovery, indicative of a hyperventilation pattern consistent with chronic hyperventilation syndrome, without typical symptomatic manifestations. These findings suggest underlying post-COVID respiratory dysregulation, emphasizing the importance of targeted diagnostic and therapeutic approaches for persistent respiratory symptoms in long COVID patients.

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.

[Post-COVID-19 syndrome]

In the aftermath of acute infection with the severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), a large number of symptoms persist or appear, constituting a real syndrome called "long COVID-19" or "post-COVID- 19" or "post-acute COVID-19 syndrome". Its incidence is very high, half of patients showing at least one symptom at 4-6 months after Coronarovirus infectious disease 2019 (COVID-19). They can affect many organs. The most common symptom is persistent fatigue, similar to that seen after other viral infections. Radiological pulmonary sequelae are relatively rare and not extensive. On the other hand, functional respiratory symptoms, primarily dyspnoea, are much more frequent. Dysfunctional breathing is a significant cause of dyspnoea. Cognitive disorders and psychological symptoms are also very common, with anxiety, depression and post-traumatic stress symptoms being widely described. On the other hand, cardiac, endocrine, cutaneous, digestive or renal sequelae are rarer. The symptoms generally improve after several months, even if their prevalence at two years remains significant. Most of the symptoms are favored by the severity of the initial illness, and the psychic symptoms by the female sex. The pathophysiology of most symptoms is poorly understood. The influence of the treatments used in the acute phase is also important. Vaccination, on the other hand, seems to reduce their incidence. The sheer number of affected patients makes long-term COVID-19 syndrome a public health challenge.

Feasibility of a nasal breathing training during pulmonary rehabilitation. A pilot randomized controlled study

Hyperventilation syndrome (HVS) is a common source of dyspnea and disability. While pulmonary rehabilitation (PR) including breathing exercises is indicated, randomized controlled trial are warranted to recommend one type of breathing exercise than another. We aimed to compare during PR, the effect of 5 sessions of nasal ventilation exercise (NV+PR) versus voluntary hypoventilation (vHV+PR) on exercise dyspnea (primary outcome) and capacity and health-related quality of life in patients. In this open label randomized controlled trial, 19 HVS patients (age=48.3 ± 15.2 y.o, female/male=18/1, Nijmegen score=33 ± 7.7) were randomized in a NV+PR (n = 9) or vHV+PR (n = 10) group. Modified Medical Research Council (mMRC) dyspnea, 6-minute walking distance (6MWD) with nasal/oral ventilation were assessed before and after 3 months of PR, and questionnaires (Nijmegen, VQ-11). There was a significant effect of PR of but no significant difference between groups in the improvements of dyspnea@max exercise (time effect (T): p < 0.01; group (G): p = 0.63; group*time interaction (G*T): p = 0.49), mMRC dyspnea (T: p < 0.01; G: p = 0.45; G*T: p = 0.62), 6MWD (T: p < 0.05; G: p = 0.36; G*T: p = 0.31), VQ-11 (T: p < 0.001; G: p = 0.16; G*T: p = 0.09) and plasma HCO₃^- (T: p < 0.05; G: p = 0.93; G*T; p = 0.36), Yet, Nijmegen score (T: p < 0.01; G: p = 0.32; G*T: p < 0.05) improvement was larger in NV+PR group. The exercise oronasal breathing shift during the 6MWT was significantly delayed in all patients (T: p < 0.05; G: p = 0.30; G*T: p = 0.32) and positively correlated with plasma HCO₃^-(r = 0.42; p < 0.05). Nasal exercise was not superior versus voluntary hypoventilation during PR in HVS patients. Yet, nasal exercise appeared feasible, leading to acquisition of a nasal breathing pattern during walking, improvement of PR outcomes and ventilatory alkalosis. The link between nasal breathing and hyperventilation is discussed in the light of the nasal ventilation rhythm in the limbic system and its role on the limbic emotional and ventilatory functions.

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.

A Pilot Study on a Nurse Rehabilitation Program: Could It Be Applied to COVID-19 Patients?

(1) Background: An aging population, pollution and an increase in life habits that are harmful to respiratory health, and more recently the COVID-19 pandemic, have led to an increase in chronic respiratory diseases. Thus, this pilot study aims to describe an intervention program on the training of respiratory patients to maintain airway permeability and preventing complications. (2) Methods: An observational, analytical, and prospective study was proposed. After the initial evaluation of each user during hospitalization, the program started with two sessions, at discharge for the second phase, and fifteen days after discharge for the third phase. Throughout the program's implementation, the modified Medical Research Council scale and the Barthel Index were applied. (3) Results: The population studied aged between 39 and 76 years, diagnosed with pneumonia or chronic obstructive pulmonary disease, showed a significant improvement in the degrees of dyspnea and levels of functionality, as well as an adequate level of learning. (4) Conclusions: This program positively impacted the patients' independence by reducing dyspnea and increasing functionality of the patients included in this study. The set of exercises and techniques can be replicated at home and may be fundamental in the management of respective recovery, as well as in the COVID-19 pandemic.

Pilot study of physiotherapist-led versus music therapist-led breathing control exercises for young adults living with breathing pattern disorder: a randomised controlled trial protocol

INTRODUCTION

Breathing pattern disorder (BPD) is an abnormal breathing pattern associated with biochemical, biomechanical and psychophysiological changes. While physiotherapy is often offered, limited evidence-based therapies for BPD are available. Music therapy-based singing exercises have been shown to improve quality of life for individuals with respiratory conditions and may also be beneficial for individuals living with BPD. No study has previously compared these participatory interventions in the treatment of people living with BPD.

METHODS AND ANALYSIS

This is a study protocol for an assessor blinded 1:1 randomised controlled trial and qualitative interview study. Forty participants aged 18-40 years who score at least 19 on the Nijmegen Questionnaire (NQ) and do not have any underlying respiratory conditions will be recruited. Participants will be randomised to receive either physiotherapy-led or music therapy-led breathing exercises for 6 weeks. The primary outcome will be between-group difference in NQ post-intervention. Semistructured interviews with a purposive sample of participants will be performed. Qualitative data will be analysed using thematic analysis to better understand participants' intervention and trial experiences.

ETHICS AND DISSEMINATION

This study has received ethical approval by Brunel University London College of Health, Medicine and Life Science's Research Ethics Committee (32483-MHR-Mar/2022-38624-3). The anonymised completed dataset will be made available as an open-access file via Brunel University London Figshare and the manuscript containing anonymised patient data will be published in an open-access journal.

TRIAL REGISTRATION NUMBER

This trial is registered on the Open Science Framework Registry (https://osf.io/u3ncw).

Blood Gas Analysis Results and Serum Lactate Levels in Patients with Psychogenic Hyperventilation and Urinary Tract Infection with Suspected Sepsis: A Retrospective Comparative Study

Objective The prognosis differs considerably between patients with psychogenic hyperventilation syndrome (HVS) and those with urinary tract infection (UTI)-associated sepsis; however, the nonspecific symptoms and signs make the diagnosis and management difficult. We herein report the utility of a blood gas analysis for distinguishing HVS from UTI with suspected sepsis. Methods This single-center retrospective cohort study was conducted in a tertiary-care hospital in Japan. Patients ≥18 years old with a quick Sequential Organ Failure Assessment (qSOFA) score ≥2 and HVS or UTIs were included. The results of an arterial blood gas (ABG) or venous blood gas (VBG) analysis of the two groups were compared using the Mann-Whitney U test. We used a receiver-operating characteristic (ROC) curve analysis of the arterial pH and arterial PCO₂ to assess the ability of these analyses to distinguish HVS from UTI with suspected sepsis. Results A total of 64 patients with HVS (ABG, n=14; VBG, n=50) and 53 with UTI with suspected sepsis (ABG, n=35; VBG, n=18) were included. Patients with HVS had alkalemia and lower PCO₂ levels than patients with UTI with suspected sepsis, but the serum lactate levels were similar between the groups. The ROC analysis determined the pH cut-off value to be 7.509 (sensitivity: 0.91; specificity: 0.86) and the PCO₂ cut-off value to be 21.6 mmHg (sensitivity: 1.00; specificity: 0.64). Conclusion Elevated serum lactate levels alone cannot be used to differentiate between patients with HVS and those with UTI with suspected sepsis, but the degree of pH and PCO₂ abnormality can help with the differential diagnosis.

Novel Real-Time OEP Phase Angle Feedback System for Dysfunctional Breathing Pattern Training-An Acute Intervention Study

Dysfunctional breathing patterns (DBP) can have an impact on an individual’s quality of life and/or exercise performance. Breathing retraining is considered to be the first line of treatment to correct breathing pattern, for example, reducing ribcage versus abdominal movement asynchrony. Optoelectronic plethysmography (OEP) is a non-invasive 3D motion capture technique that measures the movement of the chest wall. The purpose of this study was to investigate if the use of a newly developed real-time OEP phase angle and volume feedback system, as an acute breathing retraining intervention, could result in a greater reduction of phase angle values (i.e., an improvement in movement synchrony) when compared to real-time OEP volume feedback alone. Eighteen individuals with a DBP performed an incremental cycle test with OEP measuring chest wall movement. Participants were randomly assigned to either the control group, which included the volume-based OEP feedback or to the experimental group, which included both the volume-based and phase angle OEP feedback. Participants then repeated the same cycle test using the real-time OEP feedback. The phase angle between the ribcage versus abdomen (RcAbPhase), between the pulmonary ribcage and the combined abdominal ribcage and abdomen (RCpAbPhase), and between the abdomen and the shoulders (AbSPhase) were calculated during both cycle tests. Significant increases in RcAbPhase (pre: −2.89°, post: −1.39°, p < 0.01), RCpAbPhase (pre: −2.00°, post: −0.50°, p < 0.01), and AbSPhase (pre: −2.60°, post: −0.72°, p < 0.01) were found post-intervention in the experimental group. This indicates that the experimental group demonstrated improved synchrony in their breathing pattern and therefore, reverting towards a healthy breathing pattern. This study shows for the first time that dysfunctional breathing patterns can be acutely improved with real-time OEP phase angle feedback and provides interesting insight into the feasibility of using this novel feedback system for breathing pattern retraining in individuals with DBP.

Breathing Re-Education and Phenotypes of Sleep Apnea: A Review

Four phenotypes of obstructive sleep apnea hypopnea syndrome (OSAHS) have been identified. Only one of these is anatomical. As such, anatomically based treatments for OSAHS may not fully resolve the condition. Equally, compliance and uptake of gold-standard treatments is inadequate. This has led to interest in novel therapies that provide the basis for personalized treatment protocols. This review examines each of the four phenotypes of OSAHS and explores how these could be targeted using breathing re-education from three dimensions of functional breathing: biochemical, biomechanical and resonant frequency. Breathing re-education and myofunctional therapy may be helpful for patients across all four phenotypes of OSAHS. More research is urgently needed to investigate the therapeutic benefits of restoring nasal breathing and functional breathing patterns across all three dimensions in order to provide a treatment approach that is tailored to the individual patient.

Exercise/physical activity and health outcomes: an overview of Cochrane systematic reviews

BACKGROUND

Sedentary lifestyle is a major risk factor for noncommunicable diseases such as cardiovascular diseases, cancer and diabetes. It has been estimated that approximately 3.2 million deaths each year are attributable to insufficient levels of physical activity. We evaluated the available evidence from Cochrane systematic reviews (CSRs) on the effectiveness of exercise/physical activity for various health outcomes.

METHODS

Overview and meta-analysis. The Cochrane Library was searched from 01.01.2000 to issue 1, 2019. No language restrictions were imposed. Only CSRs of randomised controlled trials (RCTs) were included. Both healthy individuals, those at risk of a disease, and medically compromised patients of any age and gender were eligible. We evaluated any type of exercise or physical activity interventions; against any types of controls; and measuring any type of health-related outcome measures. The AMSTAR-2 tool for assessing the methodological quality of the included studies was utilised.

RESULTS

Hundred and fifty CSRs met the inclusion criteria. There were 54 different conditions. Majority of CSRs were of high methodological quality. Hundred and thirty CSRs employed meta-analytic techniques and 20 did not. Limitations for studies were the most common reasons for downgrading the quality of the evidence. Based on 10 CSRs and 187 RCTs with 27,671 participants, there was a 13% reduction in mortality rates risk ratio (RR) 0.87 [95% confidence intervals (CI) 0.78 to 0.96]; I2 = 26.6%, [prediction interval (PI) 0.70, 1.07], median effect size (MES) = 0.93 [interquartile range (IQR) 0.81, 1.00]. Data from 15 CSRs and 408 RCTs with 32,984 participants showed a small improvement in quality of life (QOL) standardised mean difference (SMD) 0.18 [95% CI 0.08, 0.28]; I2 = 74.3%; PI -0.18, 0.53], MES = 0.20 [IQR 0.07, 0.39]. Subgroup analyses by the type of condition showed that the magnitude of effect size was the largest among patients with mental health conditions.

CONCLUSION

There is a plethora of CSRs evaluating the effectiveness of physical activity/exercise. The evidence suggests that physical activity/exercise reduces mortality rates and improves QOL with minimal or no safety concerns.

TRIAL REGISTRATION

Registered in PROSPERO ( CRD42019120295 ) on 10th January 2019.

Effects of Diaphragmatic Breathing on Health: A Narrative Review

Background: Breathing is an essential part of life. Diaphragmatic breathing (DB) is slow and deep breathing that affects the brain and the cardiovascular, respiratory, and gastrointestinal systems through the modulation of autonomic nervous functions. However, the effects of DB on human health need to be further investigated. Methods: The author conducted a PubMed search regarding the current evidence of the effect of DB on health. Results: This review consists of a total of 10 systematic reviews and 15 randomized controlled trials (RCTs). DB appears to be effective for improving the exercise capacity and respiratory function in patients with chronic obstructive pulmonary disease (COPD). Although the effect of DB on the quality of life (QoL) of patients with asthma needs to be investigated, it may also help in reducing stress; treating eating disorders, chronic functional constipation, hypertension, migraine, and anxiety; and improving the QoL of patients with cancer and gastroesophageal reflux disease (GERD) and the cardiorespiratory fitness of patients with heart failure. Conclusions: Based on this narrative review, the exact usefulness of DB in clinical practice is unclear due to the poor quality of studies. However, it may be a feasible and practical treatment method for various disorders.

Dysfunctional breathing: what do we know?

Dysfunctional breathing (DB) is a respiratory condition characterized by irregular breathing patterns that occur either in the absence of concurrent diseases or secondary to cardiopulmonary diseases. Although the primary symptom is often dyspnea or “air hunger”, DB is also associated with nonrespiratory symptoms such as dizziness and palpitations. DB has been identified across all ages. Its prevalence among adults in primary care in the United Kingdom is approximately 9.5%. In addition, among individuals with asthma, a positive diagnosis of DB is found in a third of women and a fifth of men. Although DB has been investigated for decades, it remains poorly understood because of a paucity of high-quality clinical trials and validated outcome measures specific to this population. Accordingly, DB is often underdiagnosed or misdiagnosed, given the similarity of its associated symptoms (dyspnea, tachycardia, and dizziness) to those of other common cardiopulmonary diseases such as COPD and asthma. The high rates of misdiagnosis of DB suggest that health care professionals do not fully understand this condition and may therefore fail to provide patients with an appropriate treatment. Given the multifarious, psychophysiological nature of DB, a holistic, multidimensional assessment would seem the most appropriate way to enhance understanding and diagnostic accuracy. The present narrative review was developed as a means of summarizing the available evidence about DB, as well as improving understanding of the condition by researchers and practitioners.

Dexmedetomidine-treated hyperventilation syndrome triggered by the distress related with a urinary catheter after general anesthesia: a case report

Background

Hyperventilation syndrome (HVS) sometimes occurs in patients under stressful conditions and may provoke severe complications such as myocardial infarction and death. The authors report a case of HVS following general anesthesia, where a continuous intravenous infusion of dexmedetomidine was effective for HVS.

Case presentation

A 23-year-old male patient with recurrent tongue cancer was scheduled to undergo partial glossectomy and neck dissection. Emergence from general anesthesia was prompt. Twenty-two minutes after extubation, the patient complained of unbearable distress caused by the urinary catheter. He began to cry, with an increased respiratory rate of over 40 breaths per minute. Intravenous infusion of flurbiprofen, droperidol, and morphine was not effective. Electrocardiography and laryngofiberscopy indicated the absence of acute coronary syndrome and airway obstruction, respectively. An arterial blood gas determination showed pH 7.63, PaCO₂ 18.2 mmHg, PaO₂ 143 mmHg on O₂ mask 4 L/min, Ca²⁺ 4.29 mmol/L, and lactate 3.4 mmol/L. The patient was diagnosed with HVS. Dexmedetomidine infusion 2.0 μg/kg/h for 10 min followed by 0.7 μg/kg/h reduced respiratory rate, suppressed arousal, and disappeared the complaint of bladder distension. One hour after extubation, an arterial blood gas determination showed pH 7.33, PaCO₂ 51.3 mmHg, PaO₂ 196 mmHg on O₂ mask 4 L/min, Ca²⁺ 4.70 mmol/L, and lactate 1.5 mmol/L. After admission to the intensive care unit, dexmedetomidine infusion was maintained at the rate of 0.2 to 0.7 μg/kg/h until the following morning, and he did not complain of distress caused by the urinary catheter.

Conclusions

HVS can occur after emergence from general anesthesia, and dexmedetomidine infusion was effective for HVS.

Use of the Nijmegen Questionnaire in asthma

It remains to be seen whether dysfunctional breathing will acquire the status of an illness per se http://ow.ly/P60J7.

Primary Hyperventilation in the Emergency Department: A First Overview

Background

Primary hyperventilation is defined as a state of alveolar ventilation in excess of metabolic requirements, leading to decreased arterial partial pressure of carbon dioxide. The primary aim of this study was to characterise patients diagnosed with primary hyperventilation in the ED.

Methods

Our retrospective cohort study comprised adult (≥16 years) patients admitted to our ED between 1 January 2006 and 31 December 2012 with the primary diagnosis of primary (=psychogenic) hyperventilation.

Results

A total of 616 patients were eligible for study. Participants were predominantely female (341 [55.4%] female versus 275 [44.6%] male respectively, p <0.01). The mean age was 36.5 years (SD 15.52, range 16-85). Patients in their twenties were the most common age group (181, 29.4%), followed by patients in their thirties (121, 19.6%). Most patients presented at out-of-office hours (331 [53.7%]. The most common symptom was fear (586, 95.1%), followed by paraesthesia (379, 61.5%) and dizziness (306, 49.7%). Almost a third (187, 30.4%) of our patients had previously experienced an episode of hyperventilation and half (311, 50.5%) of patients had a psychiatric co-morbidity.

Conclusion

Hyperventilation is a diagnostic chimera with a wide spectrum of symptoms. Patients predominantly are of young age, female sex and often have psychiatric comorbidities. The severity of symptoms accompanied with primary hyperventilation most often needs further work-up to rule out other diagnosis in a mostly young population. In the future, further prospective multicentre studies are needed to evaluate and establish clear diagnostic criteria for primary hyperventilation and possible screening instruments.

Getting to grips with 'dysfunctional breathing'

Dysfunctional breathing (DB) is common, frequently unrecognised and responsible for a substantial burden of morbidity. Previously lack of clarity in the use of the term and the use of multiple terms to describe the same condition has hampered our understanding. DB can be defined as an alteration in the normal biomechanical patterns of breathing that result in intermittent or chronic symptoms. It can be subdivided into thoracic and extra thoracic forms. Thoracic DB is characterised by breathing patterns involving relatively inefficient, excessive upper chest wall activity with or without accessory muscle activity. This is frequently associated with increased residual volume, frequent sighing and an irregular pattern of respiratory effort. It may be accompanied by true hyperventilation in the minority of subjects. Extra thoracic forms include paradoxical vocal cord dysfunction and the increasingly recognised supra-glottic 'laryngomalacia' commonly seen in young sportsmen and women. While the two forms would appear to be two discreet entities they often share common factors in aetiology and respond to similar interventions. Hence both forms are considered in this review which aims to generate a more coherent approach to understanding, diagnosing and treating these conditions.

Breathing exercises for dysfunctional breathing/hyperventilation syndrome in children

BACKGROUND

Dysfunctional breathing is described as chronic or recurrent changes in breathing pattern causing respiratory and non-respiratory symptoms. It is an umbrella term that encompasses hyperventilation syndrome and vocal cord dysfunction. Dysfunctional breathing affects 10% of the general population. Symptoms include dyspnoea, chest tightness, sighing and chest pain which arise secondary to alterations in respiratory pattern and rate. Little is known about dysfunctional breathing in children. Preliminary data suggest 5.3% or more of children with asthma have dysfunctional breathing and that, unlike in adults, it is associated with poorer asthma control. It is not known what proportion of the general paediatric population is affected. Breathing training is recommended as a first-line treatment for adults with dysfunctional breathing (with or without asthma) but no similar recommendations are available for the management of children. As such, breathing retraining is adapted from adult regimens based on the age and ability of the child.

OBJECTIVES

To determine whether breathing retraining in children with dysfunctional breathing has beneficial effects as measured by quality of life indices.To determine whether there are any adverse effects of breathing retraining in young people with dysfunctional breathing.

SEARCH METHODS

We identified trials for consideration using both electronic and manual search strategies. We searched CENTRAL, MEDLINE and EMBASE. We searched the National Research Register (NRR) Archive, Health Services Research Projects in Progress (HSRProj), Current Controlled Trials register (incorporating the metaRegister of Controlled Trials and the International Standard Randomised Controlled Trial Number (ISRCTN) to identify research in progress and unpublished research. The latest search was undertaken in October 2013.

SELECTION CRITERIA

We planned to include randomised, quasi-randomised or cluster-randomised controlled trials. We excluded observational studies, case studies and studies utilising a cross-over design. The cross-over design was considered inappropriate due to the purported long-lasting effects of breathing retraining. Children up to the age of 18 years with a clinical diagnosis of dysfunctional breathing were eligible for inclusion. We planned to include children with a primary diagnosis of asthma with the intention of undertaking a subgroup analysis. Children with symptoms secondary to cardiac or metabolic disease were excluded.We considered any type of breathing retraining exercise for inclusion in this review, such as breathing control, diaphragmatic breathing, yoga breathing, Buteyko breathing, biofeedback-guided breathing modification and yawn/sigh suppression. We considered programmes where exercises were either supervised (by parents or a health professional, or both) or unsupervised. We also considered relaxation techniques and acute episode management as long as it was clear that breathing exercises were a component of the intervention.Any intervention without breathing exercises or where breathing exercises were not key to the intervention were excluded.

DATA COLLECTION AND ANALYSIS

We planned that two authors (NJB and MJ) would extract data independently using a standardised form. Any discrepancies would be resolved by consensus. Where agreement could not be reached a third review author (MLE) would have considered the paper.

MAIN RESULTS

We identified 264 potential trials and reviews from the search. Following removal of duplicates, we screened 224 papers based on title and abstract. We retrieved six full-text papers and further evaluated them but they did not meet the inclusion criteria. There were, therefore, no studies suitable for inclusion in this review.

AUTHORS' CONCLUSIONS

The results of this systematic review cannot inform clinical practice as no suitable trials were identified for inclusion. Therefore, it is currently unknown whether these interventions offer any added value in this patient group or whether specific types of breathing exercise demonstrate superiority over others. Given that breathing exercises are frequently used to treat dysfunctional breathing/hyperventilation syndrome, there is an urgent need for well-designed clinical trials in this area. Future trials should conform to the CONSORT statement for standards of reporting and use validated outcome measures. Trial reports should also ensure full disclosure of data for all important clinical outcomes.