Subjective symptoms and breathing pattern at rest and following hyperventilation in anxiety and somatoform disorders

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.

Is There a Relationship between Hyperventilation Syndrome and History of Acute SARS-CoV-2 Infection? A Cross-Sectional Study

Following COVID-19 infection, many patients suffer from long-lasting symptoms that may greatly impair their quality of life. Persisting dyspnea and other functional respiratory complaints can evoke hyperventilation syndrome (HVS) as a putative contributor to long-COVID presentation in COVID-19 survivors. We aimed to assess the possible relationship between HVS and previous acute COVID-19 infection. We designed a cross-sectional, single-center study, including all patients consecutively referred to our Lung Function and Exercise Testing Department between January and June 2021. Participants completed a systematic Nijmegen Questionnaire, a modified Medical Research Council dyspnea scale assessment, a post-COVID screening questionnaire, and performed a standardized lung function test. The population was divided according to HVS diagnosis, defined as a Nijmegen score of > 23/64. The occurrence of previous COVID-19 infection was compared according to the Nijmegen score after adjustment for potential confounders by multivariate logistic regression. In total, 2846 patients were included: 1472 men (51.7%) with a mean age of 56 (±16.6) years. A total of 455 patients (16%) declared a previous SARS-CoV-2 infection, and 590 patients presented a positive score (>23/64) in the Nijmegen Questionnaire (20.7%). Compared with COVID-19-free patients, there was an increased occurrence of HVS+ in cases of COVID-19 infection that did not require hospitalization (aOR = 1.93 [1.17−3.18]). The results of this large-scale, cross-sectional study suggest an association between HVS diagnosis and a history of COVID-19 disease in patients who were not hospitalized.

Integrative Review and Framework of Suggested Mechanisms in Primary Muscle Tension Dysphonia

PURPOSE

Despite the high prevalence of primary muscle tension dysphonia (MTD-1), its underlying mechanisms and their interrelationships have yet to be fully identified. The objectives of this integrative review were (a) to describe and classify the suggested underlying mechanisms for MTD-1, (b) to appraise the empirical evidence supporting each of the proposed mechanisms, and (c) to summarize the information in an integrative model.

METHOD

PubMed, Scopus, and CINAHL were searched for all publications pertaining to muscle tension dysphonia. Papers were retained if they included theoretical or empirical data pertaining to underlying mechanisms of MTD-1. A total of 921 papers initially qualified for screening, of which 100 remained for consideration in this review. Underlying mechanisms of MTD-1 were extracted using a consensus approach.

RESULTS

Seven broad categories of putative mechanisms involved in MTD-1 were identified: psychosocial, autonomic, sensorimotor, respiratory, postural, inflammatory, and neuromuscular. These categories were further divided into 19 subcategories detailed in the body of this review article. Based on the reviewed evidence, our proposed integrative model presents MTD-1 as an idiosyncratic motor adaptation to physiological perturbation or perceived threat. Under this model, physiologically or psychologically aversive stimuli can instigate a series of motor adaptations at multiple levels of the nervous system, ultimately disturbing muscle activation patterns and their biomechanical outcomes. Importantly, these adaptations appear to have the potential to become chronic even after threatening stimuli are withdrawn.

CONCLUSIONS

The proposed model highlights the importance of personalized rehabilitation in MTD-1 treatment. Limitations of the literature are discussed to provide guidance for future research aimed at improving our understanding of MTD-1.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19586065.

Verification of the Psychometric Characteristics of the Nijmegen Questionnaire for the Diagnosis of Dysfunctional Breathing During the COVID-19 Pandemic on a Russian Sample

The purpose of the study was to check the psychometric properties of the Nijmegen questionnaire (NQ) (Van Dixhoorn, Duivenvoorden, 1985), aimed at diagnosing the presence of signs of dysfunctional breathing (DВ) according to self–reports of respondents in the conditions of the COVID-19 pandemic in a Russian-speaking sample. The study sample consisted of 1 362 respondents (1 153 women and 209 men) aged 18 to 88 years (mean age 38.3±11.4) who filled out an online questionnaire from April to December 2020 during the COVID-19 pandemic. The following methods were used to test the construct validity of the Russian version of the NQ: 1) Perceived Stress Scale-10 (PSS-10; Ababkov et al., 2016); 2) State-Trait Anxiety Inventory (STAI, Khanin, 1976), the scales of which were modified to measure the level of anxiety during a pandemic (State anxiety) and before the pandemic (Trait anxiety) (Pervichko et al., 2020); 3) The Symptom Check List-32 (SCL-32) (Mitina, Gorbunova, 2011); (4) An abridged version of the Six-Factor Personality Inventory HEXACO-24 (Egorova et al, 2019). The study participants also completed a socio-demographic questionnaire (Pervichko et al., 2020). The results of checking the Russian-language version of the NQ for reliability are presented: the value of the internal consistency coefficient α-Cronbach for the integral indicator = 0.877. Four subscales were identified, the indicators of which improved when the questionnaire was reduced to 10 points. Internal convergent and discriminant validity has been verified for the abridged version. The external constructive validity of the questionnaire is proved. High rates of correlation with stress, situational and personal anxiety, as well as other symptoms of psychological distress were revealed. In addition, a high correlation with emotionality has been established. The problem of the "threshold" value of NQ required to identify the formed symptom complex of DB is discussed. The prevalence of DB symptoms before and during the pandemic was compared. A significant difference in the indicators on the scale for men and women was established. Using the obtained Russian-language version of NQ, it was shown that in the conditions of the COVID-19 pandemic, 27.7% of the study participants who were not sick with COVID-19 showed signs of a formed DB symptom complex, which is more than twice higher than the population indicators in the pre-pandemic period. The frequency of occurrence of the holistic symptom complex of DB in women is three times higher than in men: 31.0% vs 9.1% (p<0.001). The results of the study allow us to conclude that NQ is a reliable and valid tool for diagnosing the severity of DB symptoms, which can be recommended for use as an express diagnostic tool for the presence of psychogenically caused respiratory disorders in persons complaining of "difficulty breathing" in the absence of objective grounds.

Dysfunctional Breathing in Children and Adults With Asthma

Asthma occurs across the life course. Its optimal treatment includes the use of personalized management plans that recognize the importance of co-morbidities including so-called "dysfunctional breathing." Such symptoms can arise as a result of induced laryngeal obstruction (ILO) or alterations in the mechanics of normal breathing called breathing pattern disorders. Whilst these two types of breathing abnormalities might be related, studies tend to focus on only one of them and do not consider their relationship. Evidence for these problems amongst childhood asthmatics is largely anecdotal. They seem rare in early childhood. Both types are more frequently recognized in the second decade of life and girls are affected more often. These observations tantalizingly parallel epidemiological studies characterizing the increasing prevalence and severity of asthma that also occurs amongst females after puberty. Exercise ILO is more common amongst adolescents and young adults. It should be properly delineated as it might be causally related to specific treatable factors. More severe ILO occurring at rest and breathing pattern disorders are more likely to be occurring within a psychological paradigm. Dysfunctional breathing is associated with asthma morbidity through a number of potential mechanisms. These include anxiety induced breathing pattern disorders and the enhanced perception of subsequent symptoms, cooling and drying of the airways from hyperventilation induced hyperresponsiveness and a direct effect of emotional stimuli on airways constriction via cholinergic pathways. Hyperventilation is the most common breathing pattern disorder amongst adults. Although not validated for use in asthma, the Nijmegen questionnaire has been used to characterize this problem. Studies show higher scores amongst women, those with poorly controlled asthma and those with psychiatric problems. Evidence that treatment with breathing retraining techniques is effective in a primary care population including all types of asthmatics suggests the problem might be more ubiquitous than just these high-risk groups. Future challenges include the need for studies characterizing all types of dysfunctional breathing in pediatric and adult patient cohorts and clearly defined, age appropriate, interventional studies. Clinicians caring for asthmatics in all age groups need to be aware of these co-morbidities and routinely ask about symptoms that suggest these problems.

Mediators of Change in Capnometry Guided Respiratory Intervention for Panic Disorder

Capnometry guided respiratory interventions have shown promising results in the treatment of panic disorder, but mechanisms of change are not yet well-understood. The current study examined changes in end-tidal carbon dioxide (ETCO₂), anxiety sensitivity, and perceived control as mediators of panic symptom change. Sixty-nine adults with panic disorder received 4 weeks of respiratory training, and panic symptom severity and potential mediators were assessed at Pre-treatment, Mid-treatment, Post-treatment, 2-month follow-up, and 12-month follow-up. Multilevel mediation analyses showed that changes in perceived control significantly mediated changes in panic disorder severity and that for individuals who were hypocapnic at pre-treatment, ETCO₂ was a significant mediator of symptom outcome. Findings provide further evidence that changes in perceived control, and improvements in respiratory dysregulation for hypocapnic individuals specifically, underlie symptom improvement from capnometry guided respiratory intervention for panic disorder.

Relationships between trait and respiratory parameters during quiet breathing in normal subjects

Respiratory patterns are influenced and altered by various emotional changes. In the present study, we investigated how respiratory patterns differ from individual to individual during quiet breathing. We examined the State-Trait Anxiety Inventory and various respiratory parameters in 16 healthy male subjects. Tidal volume was significantly larger and respiratory rate (RR) was significantly higher in both the higher trait (HT) and higher state (HS) anxiety groups compared to the lower trait and lower state anxiety groups. Inspiratory (T _I) and expiratory time (T _E) was significantly shorter in both the HT and HS anxiety groups. There was no significant difference in minute ventilation between these two groups. End-tidal CO₂%, heart rate, and oxygen uptake ([Formula: see text]) also showed no significant differences. V _T showed a negative correlation and RR showed a positive correlation with trait scores. T _I and T _E showed a negative correlation with trait anxiety scores. However, no other respiratory parameter showed any correlation. These results suggest that the respiratory rhythm reflected by RR is affected by the activity generated in the higher center in accordance with the level of trait anxiety during quiet breathing in awake humans.

Increased ventilatory variability and complexity in patients with hyperventilation disorder

It has been hypothesized that hyperventilation disorders could be characterized by an abnormal ventilatory control leading to enhanced variability of resting ventilation. The variability of tidal volume (VT) often depicts a nonnormal distribution that can be described by the negative slope characterizing augmented breaths formed by the relationship between the probability density distribution of VT and VT on a log-log scale. The objectives of this study were to describe the variability of resting ventilation [coefficient of variation (CV) of VT and slope], the stability in respiratory control (loop, controller and plant gains characterizing ventilatory-chemoresponsiveness interactions) and the chaotic-like dynamics (embedding dimension, Kappa values characterizing complexity) of resting ventilation in patients with a well-defined dysfunctional breathing pattern characterized by air hunger and constantly decreased PaCO2 during a cardiopulmonary exercise test. Compared with 14 healthy subjects with similar anthropometrics, 23 patients with hyperventilation were characterized by increased variability of resting tidal ventilation (CV of VT median [interquartile]: 26% [19-35] vs. 36% [28–48], P = 0.020; slope: −6.63 [−7.65; −5.36] vs. −3.88 [−5.91; −2.66], P = 0.004) that was not related to increased chemical drive (loop gain: 0.051 [0.039–0.221] vs. 0.044 [0.012–0.087], P = 0.149) but that was related to an increased ventilatory complexity (Kappa values, P < 0.05). Plant gain was decreased in patients and correlated with complexity (with Kappa 5 − degree 5: Rho = −0.48, P = 0.006). In conclusion, well-defined patients suffering from hyperventilation disorder are characterized by increased variability of their resting ventilation due to increased ventilatory complexity with stable ventilatory-chemoresponsiveness interactions.

The Nijmegen Questionnaire and dysfunctional breathing

The Nijmegen Questionnaire is useful to quantify and assess the normality of subjective sensations http://ow.ly/MBJj1.

Hyperventilation in asthma: a validation study of the Nijmegen Questionnaire--NQ

INTRODUCTION

The Nijmegen questionnaire (NQ) has previously been used for screening the hyperventilation syndrome (HVS) in asthmatics. However, no validity study has been reported so far.

OBJECTIVE

To examine the validity and reliability of the NQ in asthma patients and identify the prevalence of HVS.

METHODS

The NQ (n = 162) was examined for translation, construct, cross-sectional and discriminant validity as well as for internal consistency and test-retest reliability.

RESULTS

Principal component analysis and exploratory factor analysis revealed a single factor solution with 11 items and 58.6% of explained variability. These 11 NQ items showed high internal consistency (Cronbach's alpha = 0.92) and test-retest reliability (IR = 0.98). Higher NQ scores were found in the following subgroups: women versus men (p < 0.01); participants with moderate versus mild asthma (p < 0.001) or uncontrolled versus controlled asthma (p < 0.001), and participants with breath-hold time (BHT) < 30 versus ≥ 30 s (p < 0.01) or end-tidal CO2 (ETCO2) ≤ 35 versus >35 mmHg (p < 0.001). A cut-off score of >17 discriminated the participants with regard to the presence of HVS. The NQ showed 92.73% sensitivity and 91.59% specificity. The total NQ score was found significantly correlated with ETCO2 (r = -0.68), RR (r = 0.66) and BHT (r = -0.65). The prevalence of HVS was found 34%.

CONCLUSION

The NQ is a valid and reliable questionnaire for screening HVS in patients with stable mild-to-moderate asthma.

Respiratory muscle tension as symptom generator in individuals with high anxiety sensitivity

OBJECTIVE

Anxiety and panic are associated with the experience of a range of bodily symptoms, in particular unpleasant breathing sensations (dyspnea). Respiratory theories of panic disorder have focused on disturbances in blood gas regulation, but respiratory muscle tension as a source of dyspnea has not been considered. We therefore examined the potential of intercostal muscle tension to elicit dyspnea in individuals with high anxiety sensitivity, a risk factor for developing panic disorder.

METHODS

Individuals high and low in anxiety sensitivity (total N=62) completed four tasks: electromyogram biofeedback for tensing intercostal muscle, electromyogram biofeedback for tensing leg muscles, paced breathing at three different speeds, and a fine motor task. Global dyspnea, individual respiratory sensations, nonrespiratory sensations, and discomfort were assessed after each task, whereas respiratory pattern (respiratory inductance plethysmography) and end-tidal carbon dioxide (capnography) were measured continuously.

RESULTS

In individuals with high compared to low anxiety sensitivity, intercostal muscle tension elicited a particularly strong report of obstruction (M=5.1, SD=3.6 versus M=2.5, SD=3.0), air hunger (M=1.9, SD=2.1 versus M=0.4, SD=0.8), hyperventilation symptoms (M=0.6, SD=0.6 versus M=0.1, SD=0.1), and discomfort (M=5.1, SD=3.2 versus M=2.2, SD=2.1) (all p values<.05). This effect was not explained by site-unspecific muscle tension, voluntary manipulation of respiration, or sustained task-related attention. Nonrespiratory control sensations were not significantly affected by tasks (F<1), and respiratory variables did not reflect any specific responding of high-Anxiety Sensitivity Index participants to intercostal muscle tension.

CONCLUSIONS

Respiratory muscle tension may contribute to the respiratory sensations experienced by panic-prone individuals. Theories and treatments for panic disorder should consider this potential source of symptoms.

Dysfunctional breathing phenotype in adults with asthma - incidence and risk factors

Background

Abnormal breathing patterns may cause characteristic symptoms and impair quality of life. In a cross-sectional survey 29% of adults treated for asthma in primary care had symptoms suggestive of dysfunctional breathing (DB), more likely to be female and younger, with no differences for severity of asthma. No clear risk factors were demonstrated for DB in asthma, nor the impact of asthma medication was evaluated. The objective of this study was to describe the DB phenotype in adults with asthma treated in a specialised asthma centre.

Methods

Adult patients aged 17–65 with diagnosed asthma were screened for DB using the Nijmegen questionnaire (positive predictive score >23) and confirmed by progressive exercise testing. The following were evaluated as independent risk factors for DB in the multiple regression analysis: female sex; atopy, obesity, active smoker, moderate/severe rhinitis, psychopathology, GERD, arterial hypertension; severe asthma, asthma duration > 5 years, lack of asthma control, fixed airway obstruction, fast lung function decline, frequent exacerbator and brittle asthma phenotypes; lack of ICS, use of LABA or LTRA.

Results

91 adults with asthma, mean age 35.04 ±1.19 years, 47(51.65%) females were evaluated. 27 (29.67%) subjects had a positive screening score on Nijmegen questionnaire and 16(17.58%) were confirmed by progressive exercise testing as having DB. Independent risk factors for DB were psychopathology (p = 0.000002), frequent exacerbator asthma phenotype (p = 0.01) and uncontrolled asthma (p < 0.000001).

Conclusion

Dysfunctional breathing is not infrequent in asthma patients and should be evaluated in asthma patients presenting with psychopathology, frequent severe asthma exacerbations or uncontrolled asthma. Asthma medication (ICS, LABA or LTRA) had no significant relation with dysfunctional breathing.

Relationships between measures of dysfunctional breathing in a population with concerns about their breathing

BACKGROUND

Dysfunctional breathing (DB) is implicated in physical and psychological health, however evaluation is hampered by lack of rigorous definition and clearly defined measures. Screening tools for DB include biochemical measures such as end-tidal CO(2), biomechanical measures such assessments of breathing pattern, breathing symptom questionnaires and tests of breathing function such as breath holding time.

AIM

This study investigates whether screening tools for dysfunctional breathing measure distinct or associated aspects of breathing functionality.

METHOD

84 self-referred or practitioner-referred individuals with concerns about their breathing were assessed using screening tools proposed to identify DB. Correlations between these measures were determined.

RESULTS

Significant correlations where found within categories of measures however correlations between variables in different categories were generally not significant. No measures were found to correlate with carbon dioxide levels.

CONCLUSION

DB cannot be simply defined. For practical purposes DB is probably best characterised as a multi-dimensional construct with at least 3 dimensions, biochemical, biomechanical and breathing related symptoms. Comprehensive evaluation of breathing dysfunction should include measures of breathing symptoms, breathing pattern, resting CO(2) and also include functional measures such a breath holding time and response of breathing to physical and psychological challenges including stress testing with CO(2) monitoring.

An observational investigation of dysfunctional breathing and breathing control therapy in a problem asthma clinic

OBJECTIVES

Dysfunctional breathing (DB) is recognized as an associated problem in patients with asthma and may be identified by the Nijmegen questionnaire. We conducted an observational study to determine if breathing control therapy (BCT) improved Nijmegen scores or asthma-related quality of life in patients attending a problem asthma clinic.

METHODS

Nijmegen and Mini Asthma Quality of Life (Mini-AQLQ) questionnaires were completed. Patients with a positive Nijmegen (> or = 23, DB) were referred for BCT and progressive exercise testing (PET) to seek confirmation of dysfunctional breathing. Follow-up questionnaire data were collected at 6 months.

RESULTS

A total of 102 patients were studied. The total mean Nijmegen score was 26.4 (range 1-61). Those with a score > or = 23 (DB group, n = 65, 64%) had significantly lower Mini-AQLQ (mean 2.83) than the non-DB group (n = 37, mean 4.12, 95% CI for difference 0.87, 1.87, p < 0.0001). There was a strong relationship between Nijmegen score and Mini-AQLQ (r = -0.63, p < 0.001) at baseline; 10 of 17 DB patients who completed PET showed inappropriate hyperventilation. Follow-up data, available for Nijmegen and Mini-AQLQ in 44 and 46 patients respectively, showed no significant change in either of these parameters.

CONCLUSIONS

The strong relationship between Mini-AQLQ and Nijmegen scores and poor relationship between Nijmegen scores and PET-identified inappropriate hyperventilation suggest that a positive Nijmegen score overestimates the presence of dysfunctional breathing in patients with moderate to severe asthma. We found no evidence that a moderate intensity breathing control intervention had any impact on Nijmegen scores or asthma-related quality of life in this patient group.

The language of medically unexplained dyspnea

BACKGROUND

Medically unexplained dyspnea (MUD) refers to a condition characterized by a sensation of dyspnea and is typically applied to patients presenting with anxiety and hyperventilation without cardiopulmonary explanations for their dyspnea. The diagnosis is difficult. We investigated whether descriptors of dyspnea and associated symptoms of MUD are differentially diagnostic.

METHODS

A respiratory symptom checklist incorporating 61 spontaneously reported descriptors of dyspnea was administered to 96 patients with MUD and 195 patients with cardiopulmonary diseases. Symptom factors measuring different qualitative aspects of dyspnea were derived by a principal component analysis. The separation of two patient groups in terms of symptom factors was achieved by a discriminant analysis.

RESULTS

Five factors grouped different attributes of dyspnea: urge to breathe, depth and frequency of breathing, difficulty breathing and phase of respiration, wheezing, and affective dyspnea. The other five factors grouped symptoms of anxiety, tingling, cough and sputum, palpitation, and out of control. A discriminant analysis allowed to separate two patient groups (R(2) = 0.45, p < 0.0001). The presence of urge to breathe, affective dyspnea, anxiety, and tingling pointed to the diagnosis of MUD, whereas the reporting of wheezing, cough and sputum, and palpitation indicated cardiopulmonary diseases. The sensitivity was 85%, and specificity was 88%.

CONCLUSIONS

Descriptors of dyspnea and associated symptoms allows satisfactory separation of patients with MUD from patients with cardiopulmonary diseases. A prospective study will be required to test the validity and predictive values of the descriptor model in another cohort of patients.

Repeated experiences of air hunger and ventilatory behavior in response to hypercapnia in the standardized rebreathing test: effects of anxiety

In this study, we assessed air hunger (AH) and ventilatory responses to repeated CO(2) exposures in healthy women (N=31), scoring high or low for trait anxiety. A standardized rebreathing test, implying a gradually increasing CO(2) stimulus, was administered three times with 15-min intervals. Respiratory behavior and the intensity of AH perception were measured continuously. Across repeated exposures, maximal tolerance for AH habituated and the slope of AH (increase in AH per unit increase in CO(2)) diminished. Also the dynamics of the breathing response changed across trials. The thresholds for AH and tidal volume (V(T)) moved closer to each other, whereas the threshold for the respiratory rate (RR) was generally postponed. In addition, the association between AH and V(T) was stronger than between AH and RR, and the latter association became weaker over trials, particularly in high anxious persons. This suggests that AH perception became increasingly influenced by psychological factors, especially in high anxious persons. The results suggest that habituation of perceived air hunger is depending on a complex interplay between both changes in respiratory behavior and in perceptual-cognitive processes related to trait anxiety.

Air hunger and ventilation in response to hypercapnia: Effects of repetition and anxiety

We investigated the effects of anxiety on the intensity of air hunger during gradually increasing levels of CO2 until the end-tidal fractional concentration of CO2 was 7.9% or air hunger was intolerable. Normal high and low (trait) anxious participants (N=23) went through three rebreathing trials (15 min interval). Breathing behaviour was continuously monitored and air hunger was rated every 12 s. The threshold for responding to the increased CO2 was always lower for the subjective rating than for the ventilatory response. Habituation across trials was observed for both the ventilatory response and the air hunger rating regardless of anxiety. However, beyond the threshold, the slope in air hunger ratings decreased across trials in low anxious persons and tended to increase in high anxious persons (interaction P<0.05). No differences occurred in the slopes of the breathing responses. The findings documented uncoupling of the physiological and subjective responses during CO2-induced air hunger.

Respiratory complaints in Chinese: cultural and diagnostic specificities

STUDY OBJECTIVES

We investigated the qualitative components of a wide range of Chinese descriptors of dyspnea and associated symptoms, and their relevance for clinical diagnosis.

MEASUREMENTS

Sixty-one spontaneously reported descriptors were elicited in Chinese patients to make a symptom checklist, which was administered to new groups of patients with different cardiopulmonary diseases, to patients with medically unexplained dyspnea and to healthy subjects.

RESULTS

Test-retest reliability was satisfactory for most of the descriptors. A principal component analysis on 61 descriptors yielded the following eight factors: dyspnea-effort of breathing; dyspnea-affective aspect; wheezing; anxiety; tingling; palpitation; coughing and sputum; and dying experience. Although the descriptors of dyspnea-effort of breathing resembled Western wordings and were shared by patients with a variety of diseases, the descriptors of dyspnea-affective aspect appeared to be more culturally specific and were primarily linked to the diagnosis of medically unexplained dyspnea, whereas wheezing was specifically linked to asthma.

CONCLUSIONS

Three factors of breathlessness were found in Chinese. The descriptors of dyspnea-effort of breathing and wheezing appear to be similar to Western descriptors, whereas the dyspnea-affective aspect seems to bear cultural specificity.

Hyperventilation-induced syncope: no need to panic

Accurately diagnosing and treating adult patients presenting with recurrent syncope can be extremely problematic. We present the case of a patient who presented with recurrent syncope. We propose that many cases currently classified as idiopathic may in fact be due to orthostatic hypotension secondary to hyperventilation, or simply hyperventilation-induced syncope. The presence of undiagnosed psychiatric disorders should be considered in these patients.

Breathing retraining for dysfunctional breathing in asthma: a randomised controlled trial

BACKGROUND

Functional breathing disorders may complicate asthma and impair quality of life. This study aimed to determine the effectiveness of physiotherapy based breathing retraining for patients treated for asthma in the community who have symptoms suggestive of dysfunctional breathing.

METHODS

33 adult patients aged 17-65 with diagnosed and currently treated asthma and Nijmegen questionnaire scores > or =23 were recruited to a randomised controlled trial comparing short physiotherapy breathing retraining and an asthma nurse education control. The main outcome measures were asthma specific health status (Asthma Quality of Life questionnaire) and Nijmegen questionnaire scores

RESULTS

Of the 33 who entered the study, data were available on 31 after 1 month and 28 at 6 months. The median (interquartile range) changes in overall asthma quality of life score at 1 month were 0.6 (0.05-1.12) and 0.09 (-0.25-0.26) for the breathing retraining and education groups, respectively (p=0.018), 0.42 (0.11-1.17) and 0.09 (-0.58-0.5) for the symptoms domain (p=0.042), 0.52 (0.09-1.25) and 0 (-0.45-0.45) for the activities domain (p=0.007), and 0.50 (0-1.50) and -0.25 (-0.75-0.75) for the environment domain (p=0.018). Only the change in the activities domain remained significant at 6 months (0.83 (-0.10-1.71) and -0.05 (-0.74-0.34), p=0.018), although trends to improvement were seen in the overall score (p=0.065), the symptoms domain (p=0.059), and the environment domain (p=0.065). There was a correlation between changes in quality of life scores and Nijmegen questionnaire scores at 1 month and at 6 months. The number needed to treat to produce a clinically important improvement in health status was 1.96 and 3.57 at 1 and 6 months.

CONCLUSION

Over half the patients treated for asthma in the community who have symptoms suggestive of dysfunctional breathing show a clinically relevant improvement in quality of life following a brief physiotherapy intervention. This improvement is maintained in over 25% 6 months after the intervention.

A comparison of symptom provocation procedures in psychiatry and other areas of medicine: implications for their ethical use in research

BACKGROUND

Symptom provocation is used to study a wide variety of medical disorders. In contrast to other areas of medicine, the application of these procedures to the study of mental disease has generated significant scientific, political, and public debate. Purported differences include an overabundance of these procedures in psychiatry and a lack of diagnostic and therapeutic utility. Accurate appraisal of these research designs is needed to address scientific merit and ethical concerns. This article provides a general review of challenge studies in several areas of medical research, compares purposes and methods to those used in psychiatry, and ascertains whether fundamental differences exist.

METHODS

In total, 655 challenge studies were identified using MEDLINE and PsychInfo Boolean key word searches. Information was collected from each study including the year of publication, whether subjects were healthy or patient volunteers, the disease being studied, and the study purpose (e.g., to study pathophysiology, test treatment efficacy, or diagnosis of a disorder).

RESULTS

Differences in study design, purpose, and frequency of studies across time were similar for medical and psychiatric diseases.

CONCLUSIONS

Given extensive similarity in purpose and procedures, why are psychiatric challenge studies being subjected to public criticism and special review and approval procedures? Several relevant issues are addressed including risk, scientific merit, and clinical application.

Psychosomatic symptoms and breathing pattern

OBJECTIVE

Study of the links between breathing pattern, negative affectivity, and psychosomatic complaints at rest and following hyperventilation.

METHODS

In 819 patients with anxiety and somatoform disorders and 159 healthy subjects, self-reported symptoms, breathing pattern, and end-tidal CO(2) concentration (FetCO(2)) were recorded during rest and following a hyperventilation provocation test (HVPT). The relationship between disorder category, symptoms, age, and score of STAI-trait (as a measure of negative affectivity) on the one hand, and breathing pattern on the other was investigated, separately in men and women.

RESULTS

Anxiety disorders, and to a lesser extent, somatoform disorders, were characterized by breathing instability (progressive decrease of FetCO(2) at rest during mouthpiece breathing, delayed recovery of FetCO(2) following HVPT), the mean values of respiratory frequency, and FetCO(2) being modulated by STAI-trait. After grouping the symptoms into independent factors, links were observed between symptoms and breathing pattern, independently from the presence of an anxiety or somatoform disorder.

CONCLUSION

Some symptom factors appeared to be related to a lower FetCO(2) during hyperventilation, others likely directly influenced the breathing pattern. Among those, mainly respiratory symptoms were accompanied by a reduction of FetCO(2) at rest, with slower recovery of FetCO(2) following HVPT. The latter was observed also in the presence of marked anxiety. In contrast, subjects complaining of dizziness, fainting, and paresthesias in daily life presented higher values of FetCO(2) following HVPT, probably due to a voluntary braking of ventilation during HVPT.