Multidimensional Dyspnea Profile: an instrument for clinical and laboratory research

Natural, longitudinal recovery of adults with COVID-19 using standardized rehabilitation measures

Background

While studies recommend rehabilitation following post-hospitalization recovery from COVID-19, few implement standardized tools to assess continued needs. The aim of this study was to identify post-hospitalization recommendations using an interdisciplinary needs assessment with standardized rehabilitation measures. A secondary aim was to use these tools to measure recovery over a 30-day period.

Materials and methods

Using a 30-day longitudinal design, we completed weekly rapid needs assessments in this convenience sample of 20 people diagnosed with COVID-19 discharged from the hospital to home. We computed summary statistics and used the Wilcoxon Signed Rank Test to assess change over the 4-week course of the study with alpha level = 0.05.

Results

Our sample (65% male, 47% over 50 years of age, 35% White, 37% with a confirmed diagnosis of diabetes, and 47% obese) included no patients who had required mechanical ventilation. Initial assessments demonstrated the majority of our participants were at an increased risk of falls, had disability in activities of daily living (ADL) and instrumental activities of daily living (IADL), mild cognitive impairment, and dyspnea. At the 30-day follow-up, most were independent in mobility and basic ADLs, with continued disability in IADLs and cognitive function.

Discussion

In this sample of patients who were not mechanically-ventilated, early and individualized rehabilitation was necessary. The results of this study suggest patients would benefit from a multi-disciplinary team needs assessment after medical stabilization to minimize fall risk and disability, and to prevent secondary complications resulting from post-hospital deconditioning due to COVID-19.

Swimming-Induced Pulmonary Edema: Evaluation of Prehospital Treatment With CPAP or Positive Expiratory Pressure Device

BACKGROUND

Swimming-induced pulmonary edema (SIPE) occasionally occurs during swimming in cold open water. Although optimal treatment for SIPE is unknown, non-invasive positive pressure ventilation (NPPV) is an option for prehospital treatment.

RESEARCH QUESTION

Is NPPV a feasible and safe prehospital treatment for SIPE, and which outcome measures reflect recovery after treatment?

STUDY DESIGN AND METHODS

A prospective observational study was conducted at Vansbrosimningen, Sweden's largest open water swimming event, from 2017 through 2019. Swimmers with a diagnosis of SIPE and with peripheral oxygen saturation (Spo2) of ≤ 95%, persistent respiratory symptoms, or both were eligible for the study. NPPV was administered on site as CPAP by facial mask or as positive expiratory pressure (PEP) by a PEP device. Discharge criteria were Spo2 of > 95% and clinical recovery. Four outcome measures were evaluated: Spo2, crackles on pulmonary auscultation, pulmonary edema on lung ultrasound (LUS), and patient-reported respiratory symptoms.

RESULTS

Of 119 treated individuals, 94 received CPAP, 24 received treatment with a PEP device, and one required tracheal intubation. In total, 108 individuals (91%) were discharged after NPPV for a median of 10 to 20 min and 11 individuals (9%) required hospital transfer. NPPV resulted in increased Spo2 from a median of 91% to 97% (P < .0001) together with improvement of six patient-reported respiratory symptoms (median numerical rating scales, 1-7 to 0-1; P < .0001). No significant decrease in auscultation of crackles (93% vs 87%; P = .508) or pulmonary edema on LUS (100% vs 97%; P = .500) was seen during NPPV treatment.

INTERPRETATION

NPPV administered as CPAP or via a PEP device proved feasible and safe as prehospital treatment for SIPE with a vast majority of patients discharged on site. Spo2 and patient-reported respiratory symptoms reflected recovery after treatment, whereas pulmonary auscultation or LUS findings did not.

Reliability, Validity, and Responsiveness of the DEG, a Three-Item Dyspnea Measure

BACKGROUND

Dyspnea is a common and debilitating symptom that affects many different patient populations. Dyspnea measures should assess multiple domains.

OBJECTIVE

To evaluate the reliability, validity, and responsiveness of an ultra-brief, multi-dimensional dyspnea measure.

DESIGN

We adapted the DEG from the PEG, a valid 3-item pain measure, to assess average dyspnea intensity (D), interference with enjoyment of life (E), and dyspnea burden with general activity (G).

PARTICIPANTS

We used data from a multi-site randomized clinical trial among outpatients with heart failure.

MAIN MEASURES

We evaluated reliability (Cronbach's alpha), concurrent validity with the Memorial-Symptom-Assessment-Scale (MSAS) shortness-of-breath distress-orbothersome item and 7-item Generalized-Anxiety-Disorder (GAD-7) scale, knowngroups validity with New-York-Heart-Association-Functional-Classification (NYHA) 1-2 or 3-4 and presence or absence of comorbid chronic obstructive pulmonary disease (COPD), responsiveness with the MSAS item as an anchor, and calculated a minimal clinically important difference (MCID) using distribution methods.

KEY RESULTS

Among 312 participants, the DEG was reliable (Cronbach's alpha 0.92). The mean (standard deviation) DEG score was 5.26 (2.36) (range 0-10) points. DEG scores correlated strongly with the MSAS shortness of breath distress-or-bothersome item (r=0.66) and moderately with GAD-7 categories (ρ=0.36). DEG scores were statistically significantly lower among patients with NYHA 1-2 compared to 3-4 [mean difference (standard error): 1.22 (0.27) points, p<0.01], and those without compared to with comorbid COPD [0.87 (0.27) points, p<0.01]. The DEG was highly sensitive to change, with MCID of 0.59-1.34 points, or 11-25% change.

CONCLUSIONS

The novel, ultra-brief DEG measure is reliable, valid, and highly responsive. Future studies should evaluate the DEG's sensitivity to interventions, use anchor-based methods to triangulate MCID estimates, and determine its prognostic usefulness among patients with chronic cardiopulmonary and other diseases.

Experienced Respiratory Symptoms and the Impact on Daily Life from the Perspective of People with Parkinson's Disease: A Grounded Theory

BACKGROUND

Abnormal respiratory function tests can be observed early in the course of Parkinson's disease (PD). A better understanding of the impact of respiratory dysfunction on daily life in PD is needed to prevent later occurring complications as a (aspiration) pneumonia.

OBJECTIVE

To explain which respiratory symptoms people with PD or a form of atypical parkinsonism experience and how these symptoms impact on their daily lives.

METHODS

This qualitative study used a grounded theory approach. A purposeful sample strategy was used to capture information-rich cases. Data were collected in semi-structured interviews with participants diagnosed with either PD (n = 11) or atypical parkinsonism (n = 3), all of whom had confirmed respiratory symptoms. Data were analyzed using grounded theory analysis by creating codes, categories, theoretical themes, and, ultimately, a conceptual model.

RESULTS

Four respiratory profiles emerged, describing different types of respiratory dysfunction, with various positive and negative influencing factors. First, a loss of breathing automatism was experienced. Second, episodes of breathlessness or a rapid, shallow breathing pattern were triggered by either physical exertion, fatigue, or postural deformities. Third, stress and anxiety also triggered episodes of breathlessness. Fourth, a decreased cough strength and frequent coughing. Based on these findings, we constructed a conceptual model that visualizes the relations between these four types of respiratory dysfunction and their impact on daily life, with 'discomfort' and 'avoidance of social activities' as crucial elements.

CONCLUSION

A tailored approach for each profile of respiratory dysfunction is recommended to improve respiratory dysfunction and to reduce its social impact in people with PD.

Functional MRI Correlates of Carbon Dioxide Chemosensing in Persons With Epilepsy

Objectives

Sudden unexpected death in epilepsy (SUDEP) is a catastrophic epilepsy outcome for which there are no reliable premortem imaging biomarkers of risk. Percival respiratory depression is seen in monitored SUDEP and near SUDEP cases, and abnormal chemosensing of raised blood carbon dioxide (CO2) is thought to contribute. Damage to brainstem respiratory control and chemosensing structures has been demonstrated in structural imaging and neuropathological studies of SUDEP. We hypothesized that functional MRI (fMRI) correlates of abnormal chemosensing are detectable in brainstems of persons with epilepsy (PWE) and are different from healthy controls (HC).

Methods

We analyzed fMRI BOLD activation and brain connectivity in 10 PWE and 10 age- and sex-matched HCs during precisely metered iso-oxic, hypercapnic breathing challenges. Segmented brainstem responses were of particular interest, along with characterization of functional connectivity metrics between these structures. Regional BOLD activations during hypercapnic challenges were convolved with hemodynamic responses, and the resulting activation maps were passed on to group-level analyses. For the functional connectivity analysis, significant clusters from BOLD results were used as seeds. Each individual seed time-series activation map was extracted for bivariate correlation coefficient analyses to study changes in brain connectivity between PWE and HCs.

Results

(1) Greater brainstem BOLD activations in PWE were observed compared to HC during hypercapnic challenges in several structures with respiratory/chemosensing properties. Group comparison between PWE vs. HC showed significantly greater activation in the dorsal raphe among PWE (p < 0.05) compared to HCs. (2) PWE had significantly greater seed-seed connectivity and recruited more structures during hypercapnia compared to HC.

Significance

The results of this study show that BOLD responses to hypercapnia in human brainstem are detectable and different in PWE compared to HC. Increased dorsal raphe BOLD activation in PWE and increased seed-seed connectivity between brainstem and adjacent subcortical areas may indicate abnormal chemosensing in these individuals. Imaging investigation of brainstem respiratory centers involved in respiratory regulation in PWE is an important step toward identifying suspected dysfunction of brainstem breathing control that culminates in SUDEP and deserve further study as potential imaging SUDEP biomarkers.

Symptom phenotypes in pulmonary arterial hypertension: The PAH "symptome"

Women with pulmonary arterial hypertension (PAH) experience multiple symptoms, including dyspnea, fatigue, and sleep disturbance, that impair their health-related quality of life (HRQOL). However, we know little about phenotypic subgroups of patients with PAH with similar, concurrent, multiple symptoms. The objectives of this study were to define the "symptome" by symptom cluster phenotypes and compare characteristics such as biomarkers, cardiac structure and function (echocardiography), functional capacity (6-min walk distance), and HRQOL between the groups. This cross-sectional study included 60 women with PAH. Subjects completed an assessment battery: Pulmonary Arterial Hypertension Symptom Scale, Pittsburgh Sleep Quality Index, Multidimensional Dyspnea Profile, Patient-Reported Outcomes Measurement Information System (PROMIS®) Physical Function, PROMIS® Sleep-Related Impairment, and the emPHasis-10. Subjects also underwent transthoracic echocardiography, phlebotomy, 6-min walk distance, and actigraphy. The three symptoms of dyspnea, fatigue, and sleep disturbance were used to define the symptom clusters. Other PAH symptoms, plasma and serum biomarkers, cardiac structure and function (echocardiography), exercise capacity (6-min walk distance), sleep (actigraphy), and HRQOL were compared across phenotypes. The mean age was 50 ± 18 years, 51% were non-Hispanic white, 32% were non-Hispanic Black and 40% had idiopathic PAH. Cluster analysis identified Mild (n = 28, 47%), Moderate (n = 20, 33%), and Severe Symptom Cluster Phenotypes (n = 12, 20%). There were no differences for age, race, or PAH etiology between the phenotypes. WHO functional class (p < 0.001), norepinephrine levels (p = 0.029), right atrial pressure (p = 0.001), physical function (p < 0.001), sleep onset latency (p = 0.040), and HRQOL (p < 0.001) all differed significantly across phenotypes. We identified three distinctive symptom cluster phenotypes (Mild, Moderate, and Severe) for women with PAH that also differed by PAH-related symptoms, physical function, right atrial pressure, norepinephrine levels, and HRQOL. These phenotypes could suggest targeted interventions to improve symptoms and HRQOL in those most severely affected.

Prognostic Value of the Intensive Care Respiratory Distress Observation Scale on ICU Admission

BACKGROUND

The association between dyspnea and mortality has not been demonstrated in the ICU setting. We tested the hypothesis that dyspnea (self-reported respiratory discomfort) or its observational correlates (5-item intensive care Respiratory Distress Observation Scale [IC-RDOS]) assessed on ICU admission would be associated with ICU mortality.

METHODS

Ancillary analysis of single-center data prospectively collected from 220 communicative ICU subjects allocated to a derivation cohort of 120 subjects and a separate validation cohort of 100 subjects. Dyspnea was assessed dichotomously (yes/no), with a dyspnea visual analog scale (measured in mm), and IC-RDOS was calculated. Multivariate logistic regression was used to identify factors associated with ICU and hospital mortality.

RESULTS

Dyspnea was reported by 69 (58%; median 45 [interquartile range [IQR] 32-60] mm) and 47 (47%; 38 [IQR 26-48] mm) subjects in the derivation and validation cohorts, respectively. IC-RDOS was 2.3 (1.2-3.1) and 2.4 (1.3-2.8), respectively. IC-RDOS values were higher in subjects with dyspnea than in subjects without dyspnea in both the derivation cohort (2.6 [2.2-4.6] vs 1.4 [0.9-2.4], P < .001) and the validation cohort (2.6 [2.3-4.4] vs 2.2 [1.0-2.8], P < .001). On multivariate analysis of the derivation cohort, admission for hemorrhagic shock (odds ratio 13.98), IC-RDOS (odds ratio 1.77), and Simplified Acute Physiology Score II (odds ratio 1.10) was associated with ICU mortality. Areas under the receiving operating characteristic curve of IC-RDOS to predict ICU mortality were 0.785 and 0.794 in the derivation and validation cohorts, respectively.

CONCLUSIONS

IC-RDOS, an observational correlate of dyspnea, but not dyspnea itself, was associated with higher mortality in ICU subjects.

Development of a Medium Care Unit Using an Inexperienced Respiratory Staff: Lessons Learned during the COVID-19 Pandemic

The different waves of the COVID-19 pandemic caused dramatic issues regarding the organization of care. In this context innovative solutions have to be developed in a timely manner to adapt to the organization of the care. The establishment of middle care (MC) units is a bright example of such an adaptation. A multidisciplinary MC team, including expert and non-expert respiratory health care personnel, was developed and trained to work in a COVID-19 MC unit. Important educational resources were set up to ensure rapid and effective training of the MC team, limiting the admission or delaying transfers to ICU and ensuring optimal management of palliative care. We conducted a retrospective analysis of patient data in the MC unit during the second COVID-19 wave in Belgium. The aim of this study was to demonstrate the feasibility of quickly developing an effective respiratory MC unit mixing respiratory expert and non-expert members from outside ICUs. The establishment of an MC unit during a pandemic is feasible and needed. MC units possibly relieve the pressure exerted on ICUs. A highly trained multidisciplinary team is key to ensuring the success of an MC unit during such kind of a pandemic.

Inappropriate Ventilatory Homeostatic Responses in Hospitalized COVID-19 Patients

Background

The clinical presentation of COVID-19 suggests altered breathing control - tachypnoea, relative lack of dyspnoea, and often a discrepancy between severity of clinical and radiological findings. Few studies characterize and analyse the contribution of breathing drivers and their ventilatory and perceptual responses.

Aim

To establish the prevalence of inappropriate ventilatory and perceptual response in COVID-19, by characterizing the relationships between respiratory rate (RR), dyspnoea and arterial blood gas (ABG) in a cohort of COVID-19 patients at presentation to hospital, and their post-Covid respiratory sequelae at follow-up.

Methods

We conducted a retrospective cohort study including consecutive adult patients admitted to hospital with confirmed COVID-19 between 1st March 2020 and 30th April 2020. In those with concurrent ABG, RR and documented dyspnoea status on presentation, we documented patient characteristics, disease severity, and outcomes at hospital and 6-week post-discharge.

Results

Of 492 admissions, 194 patients met the inclusion criteria. Tachypnoea was present in 75% pronounced (RR>30) in 36%, and persisted during sleep. RR correlated with heart rate (HR) (r = 0.2674), temperature (r = 0.2824), CRP (r = 0.2561), Alveolar-arterial (A-a) gradient (r = 0.4189), and lower PaO₂/FiO₂ (PF) ratio (r = −0.3636). RR was not correlated with any neurological symptoms. Dyspnoea was correlated with RR (r = 0.2932), A-a gradient (r = 0.1723), and lower PF ratio (r = −0.1914), but not correlated with PaO₂ (r = −0.1095), PaCO₂ (r = −0.0598) or any recorded neurological symptom except for altered consciousness. Impaired ventilatory homeostatic control of pH/PaCO₂ [tachypnoea (RR>20), hypocapnia (PaCO₂ <4.6 kPa), and alkalosis (pH>7.45)] was observed in 29%. This group, of which 37% reported no dyspnoea, had more severe respiratory disease (A-a gradient 38.9 vs. 12.4 mmHg; PF ratio 120 vs. 238), and higher prevalence of anosmia (21 vs. 15%), dysgeusia (25 vs. 12%), headache (33 vs. 23%) and nausea (33 vs. 14%) with similar rates of new anxiety/depression (26 vs. 23%), but lower incidence of past neurological or psychiatric diagnoses (5 vs. 21%) compared to appropriate responders. Only 5% had hypoxia sufficiently severe to drive breathing (i.e. PaO₂ <6.6 kPa). At 6 weeks post-discharge, 24% (8/34) showed a new breathing pattern disorder with no other neurological findings, nor previous respiratory, neurological, or psychiatric disorder diagnoses.

Conclusions

Impaired homeostatic control of ventilation i.e., tachypnoea, despite hypocapnia to the point of alkalosis appears prevalent in patients admitted to hospital with COVID-19, a finding typically accompanying more severe disease. Tachypnoea prevalence was between 12 and 29%. Data suggest that excessive tachypnoea is driven by both peripheral and central mechanisms, but not hypoxia. Over a third of patients with impaired homeostatic ventilatory control did not experience dyspnoea despite tachypnoea. A subset of followed-up patients developed post-covid breathing pattern disorder.

Validation of the Dyspnoea-12 and Multidimensional Dyspnea profile among older Swedish men in the population

Background

The Dyspnoea-12 (D12) and Multidimensional dyspnea profile (MDP) are commonly used instruments for assessing multiple dimensions of breathlessness but have not been validated in older people in the population. The aim of this study was to validate the D12 and MDP in 73-years old men in terms of the instruments’ underlying factor structures, internal consistency, and validity.

Methods

A postal survey was sent out to a population sample of 73-years old men (n = 1,193) in southern Sweden. The two-factor structures were evaluated with confirmatory factor analysis, internal consistency with Cronbach's alpha, and validity using Pearson´s correlations with validated scales of breathlessness, anxiety, depression, fatigue, physical/mental quality of life, body mass index (BMI), and cardiorespiratory disease.

Results

A total 684 men were included. Respiratory and cardiovascular disease were reported by 17% and 38%, respectively. For D12 and MDP, the proposed two-factor structure was not fully confirmed in this population. Internal consistency was excellent for all D12 and MDP domain scores (Cronbach's alpha scores > 0.92), and the instruments’ domains showed concurrent validity with other breathlessness scales, and discriminant validity with anxiety, depression, physical/mental quality of life, BMI, and cardiorespiratory disease.

Conclusions

In a population sample of 73-years old men, the D12 and MDP had good psychometrical properties in terms of reliability and validity, which supports that the instruments are valid for use in population studies of older men.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03166-5.

Evaluation of the Norwegian version of the Dyspnoea-12 questionnaire in patients with COPD

BACKGROUND

The Dyspnoea-12 (D-12) questionnaire is widely used and tested in patients with breathing difficulties. The objective of this study was to translate and undertake the first evaluation of the measurement properties of the Norwegian version of the D-12 in patients with chronic obstructive pulmonary disease (COPD) attending a 4-week inpatient pulmonary rehabilitation programme.

METHODS

Confirmatory factor analysis was used to assess structural validity. Fit to the Rasch partial credit model and differential item functioning (DIF) were assessed in relation to age, sex and comorbidity. Based on a priori hypotheses, validity was assessed through comparisons with scores for the COPD Assessment Test (CAT), Hospital Anxiety and Depression Scales (HADS) and clinical variables.

RESULTS

There were 203 (86%) respondents with a mean age (SD) of 65.2 (9.0) years, and 49% were female. The D-12 showed satisfactory structural validity including presence of physical and affective domains. There was acceptable fit to Rasch model including unidimensionality for the two domains, and no evidence of DIF. Correlations with scores for the CAT, HADS and clinical variables were as hypothesised and highest for domains assessing similar aspects of health.

CONCLUSIONS

The Norwegian version of the D-12 showed good evidence for validity and internal consistency in this group of patients with COPD, including support for two separate domains. Further testing for these measurement properties is recommended in other Norwegian patients with dyspnoea.

Relationships between self-reported dyspnea, health conditions and frailty among Brazilian community-dwelling older adults: a cross-sectional study

CONTEXT

Dyspnea is a symptom present in several chronic diseases commonly seen among older adults. Since individuals with dyspnea tend to stay at rest, with consequently reduced levels of physical activity, they are likely to be at greater risk of developing frailty, especially at older ages.

DESIGN AND SETTING

Cross-sectional study at community level, Brazil.

OBJECTIVE

To analyze the relationships between self-reported dyspnea, health conditions and frailty status in a sample of community-dwelling older adults.

METHOD

Secondary data from the follow-up of the Frailty in Brazilian Elderly (FIBRA) study, involving 415 community-dwelling older adults (mean age: 80.3 ± 4.68 years), were used. The variables analyzed were sociodemographic characteristics, reported dyspnea, clinical data and frailty phenotype. Associations between dyspnea and other variables (age, sex, education and body mass index) were verified through the crude (c) and adjusted (a) odds ratios.

RESULTS

The prevalence of dyspnea in the entire sample was 21.0%. Dyspnea was more present in individuals with pulmonary diseases, heart disease, cancer and depression. Older adults with multimorbidities (adjusted odds ratio, ORa = 2.91; 95% confidence interval, CI = 1.41-5.99) and polypharmacy (ORa = 2.02; 95% CI = 1.15-3.54) were more likely to have dyspnea. Those who reported dyspnea were 2.54 times more likely to be frail (ORa = 2.54; 95% CI = 1.08-5.97), and fatigue was their most prevalent phenotype component.

CONCLUSION

Dyspnea was associated with different diseases, multimorbidities, polypharmacy and frailty. Recognizing the factors associated with dyspnea may contribute to its early identification and prevention of its negative outcomes among older adults.

Breathing control, brain, and bodily self-consciousness: Toward immersive digiceuticals to alleviate respiratory suffering

Breathing is peculiar among autonomic functions through several characteristics. It generates a very rich afferent traffic from an array of structures belonging to the respiratory system to various areas of the brain. It is intimately associated with bodily movements. It bears particular relationships with consciousness as its efferent motor control can be automatic or voluntary. In this review within the scope of "respiratory neurophysiology" or "respiratory neuroscience", we describe the physiological organisation of breathing control. We then review findings linking breathing and bodily self-consciousness through respiratory manipulations using virtual reality (VR). After discussing the currently admitted neurophysiological model for dyspnea, as well as a new Bayesian model applied to breathing control, we propose that visuo-respiratory paradigms -as developed in cognitive neuroscience- will foster insights into some of the basic mechanisms of the human respiratory system and will also lead to the development of immersive VR-based digital health tools (i.e. digiceuticals).

Adjunctive inspiratory muscle training during a rehabilitation program in patients with breast cancer: an exploratory double-blind, randomized, controlled pilot study

Objective

To investigate whether inspiratory muscle training (IMT) offered adjunctively to an exercise training program reduces symptoms of dyspnea in survivors of breast cancer.

Design

Double-blind, parallel-group, randomized controlled trial.

Setting

Outpatient rehabilitation program in a university hospital.

Participants

Ninety-eight female patients with breast cancer who completed adjuvant treatment and subsequently entered cancer rehabilitation were screened for participation. Inclusion criteria were reduced inspiratory muscle strength and/or symptoms of dyspnea. Twenty patients (N=20) were randomly assigned to an intervention group (n=10) or a control group (n=10).

Intervention

Both groups received a 3-month exercise training program in combination with either IMT (intervention) or sham-IMT (control).

Main Outcome Measures

Changes in dyspnea intensity perception (10-point Borg Scale) at comparable time points (isotime) during constant work rate cycling was the primary outcome. Secondary outcomes included changes in respiratory muscle function, exercise capacity, and changes in symptoms of dyspnea during daily life (Transitional Dyspnea Index [TDI]).

Results

The intervention group achieved a larger reduction in exertional dyspnea at isotime compared with the control group (−1.8 points; 95% CI, −3.7 to 0.13; P=.066). The intervention group also exhibited larger improvements in dyspnea during daily life (TDI score, +2.9 points; 95% CI, 0.5-5.3; P=.022) and improved both respiratory muscle endurance (+472 seconds; 95% CI, 217-728; P=.001) and cycling endurance (+428 seconds; 95% CI, 223-633; P=.001) more than the control group.

Conclusions

Because of the limited sample size all obtained findings need to be interpreted with caution. The study offers initial insights into the potential of adjunctive IMT in selected survivors of breast cancer. Larger multicenter studies should be performed to further explore the potential role and general acceptance of this intervention as a rehabilitation tool in selected patients after breast cancer treatment.

Cardiorespiratory responses to muscle metaboreflex activation in fibrosing interstitial lung disease

New Findings

What is the central question of this study?

We determined whether sensory feedback from metabolically sensitive skeletal muscle afferents (metaboreflex) causes a greater ventilatory response and higher dyspnoea ratings in fibrosing interstitial lung disease (FILD).

What is the main finding and its importance?

Ventilatory responses and dyspnoea ratings during handgrip exercise and metaboreflex isolation were not different in FILD and control groups. Blood pressure and heart rate responses to handgrip were attenuated in FILD but not different to controls during metaboreflex isolation. These findings suggest that the muscle metaboreflex contribution to the respiratory response to exercise is not altered in FILD.

Abstract

Exercise limitation and dyspnoea are hallmarks of fibrosing interstitial lung disease (FILD); however, the physiological mechanisms are poorly understood. In other respiratory diseases, there is evidence that an augmented muscle metaboreflex may be implicated. We hypothesized that metaboreflex activation in FILD would result in elevated ventilation and dyspnoea ratings compared to healthy controls, due to augmented muscle metaboreflex. Sixteen FILD patients (three women, 69±14 years; mean±SD) and 16 age‐matched controls (four women, 67±7 years) were recruited. In a randomized cross‐over design, participants completed two min of rhythmic handgrip followed by either (i) two min of post‐exercise circulatory occlusion (PECO trial) to isolate muscle metaboreflex activation, or (ii) rested for four min (Control trial). Minute ventilation (V˙E; pneumotachometer), dyspnoea ratings (0–10 Borg scale), mean arterial pressure (MAP; finger photoplethysmography) and heart rate (HR; electrocardiogram) were measured. V˙E was higher in the FILD group at baseline and exercise increased V˙E similarly in both groups. V˙E remained elevated during PECO, but there was no between‐group difference in the magnitude of this response (ΔV˙E FILD 4.2 ± 2.5 L·min^–1 vs. controls 3.6 ± 2.4 L·min^–1, P = 0.596). At the end of PECO, dyspnoea ratings in FILD were similar to controls (1.0 ± 1.3 units vs. 0.5 ± 1.1 units). Exercise increased MAP and HR (P < 0.05) in both groups; however, responses were lower in FILD. Collectively, these findings suggest that there is not an augmented effect of the muscle metaboreflex on breathing and dyspnoea in FILD, but haemodynamic responses to handgrip are reduced relative to controls.

'The body says it': the difficulty of measuring and communicating sensations of breathlessness

Breathlessness is a sensation affecting those living with chronic respiratory disease, obesity, heart disease and anxiety disorders. The Multidimensional Dyspnoea Profile is a respiratory questionnaire which attempts to measure the incommunicable different sensory qualities (and emotional responses) of breathlessness. Drawing on sensorial anthropology we take as our object of study the process of turning sensations into symptoms. We consider how shared cultural templates of 'what counts as a symptom' evolve, mediate and feed into the process of bodily sensations becoming a symptom. Our contribution to the field of sensorial anthropology, as an interdisciplinary collaboration between history, anthropology and the medical humanities, is to provide a critique of how biomedicine and cultures of clinical research have measured the multidimensional sensorial aspects of breathlessness. Using cognitive interviews of respiratory questionnaires with participants from the Breathe Easy groups in the UK, we give examples of how the wording used to describe sensations is often at odds with the language those living with breathlessness understand or use. They struggle to comprehend and map their bodily experience of sensations associated with breathlessness to the words on the respiratory questionnaire. We reflect on the alignment between cognitive interviewing as a method and anthropology as a disciplinary approach. We argue biomedicine brings with it a set of cultural assumptions about what it means to measure (and know) the sensorial breathless body in the context of the respiratory clinic (clinical research). We suggest the mismatch between the descriptions (and confusion) of those responding to the respiratory questionnaire items and those selecting the vocabularies in designing it may be symptomatic of a type of historical testimonial epistemic injustice, founded on the prioritisation of clinical expertise over expertise by experience.

Psychological distress prior to surgery is related to symptom burden and health status in lung cancer survivors

PURPOSE

Patients with lung cancer experience a variety of distressing symptoms which could adversely affect quality of life. The aim of this study was to determine whether psychological distress prior to surgery is associated to health status and symptom burden in lung cancer survivors.

METHODS

A longitudinal observational study with 1-year follow-up was carried out. Health status was measured by the WHO Disability Assessment Scale (WHO-DAS 2.0), the Euroqol-5 dimensions (EQ-5D) and the Pittsburgh Sleep Quality Index (PSQI). Symptoms severity included dyspnoea (Multidimensional Profile of Dyspnoea); pain (Brief Pain Inventory); fatigue (Fatigue Severity Scale); and cough (Leicester Cough Questionnaire).

RESULTS

One hundred seventy-four lung cancer patients were included. Patients in the group with psychological distress presented a worse self-perceived health status, functionality and sleep quality. The group with psychological distress also presented higher dyspnoea, fatigue and pain.

CONCLUSION

Patients with psychological distress prior surgery present with a greater symptom burden and a poorer self-perceived health status, lower functionality and sleep quality, than patients without distress 1 year after the lung resection.

Physical and affective components of dyspnoea are improved by pulmonary rehabilitation in COPD

Background

Dyspnoea is a multidimensional experience of breathing discomfort, but its affective dimension is unfrequently assessed in people with chronic obstructive pulmonary disease (COPD). We evaluated the effectiveness of a home-based pulmonary rehabilitation (PR) programme on the physical and affective components of dyspnoea assessed by the Dyspnoea-12 (D-12) questionnaire. We also determined the baseline characteristics that contributed to the change in D-12 scores.

Methods

In this retrospective study, 225 people with COPD (age, 65±11 years; forced expiratory volume in 1 s (FEV₁), 35±15% of predicted value) were enrolled into a person-centric home-based PR, consisting of a weekly supervised 90 min home session during 8 weeks. D-12 questionnaire, health status, anxiety and depressive symptoms, exercise tolerance and general fatigue were assessed at baseline (M0), at the end of PR programme (M2), and 8 (M8) and 14 months (M14) after M0. Multivariable analysis of covariance (ANCOVA) models were performed to identify the baseline characteristics that contributed to the change in D-12 scores.

Results

Both physical and affective components of dyspnoea and all the other outcome measures were improved at M2, M8 and M14 compared with baseline (p<0.05). Baseline body mass index was the only significant independent predictor of the changes in physical dyspnoea score, while the change in the affective dimension of dyspnoea after PR was associated with FEV₁, anxiety symptoms and exercise tolerance (6 min stepper test). However, since these variables had only a small impact on the changes in D-12 questionnaire scores, results from the ANCOVA analysis should be taken cautiously.

Conclusion

Both physical and affective components of dyspnoea were improved, at short term and long term, by 8 weeks of individualised home-based PR. The present results support the importance of assessing dyspnoea as a multidimensional experience during PR, warranting replication by robustly designed randomised and controlled studies.

Hypnosis for the Management of COPD-related anxiety and dyspnea in Pulmonary Rehabilitation - rationale and design for a cluster-randomised, active-control trial [HYPNOBPCO_2]

Complementary psychological care is recommended for COPD, as it significantly reduces anxiety and boosts the pulmonary rehabilitation efficacy. In a precedent trial (HYPNOBPCO_1, ISRCTN10029862), administering a single hypnosis session was linked to reduced anxiety and improved breathing mechanics in intermediate and advanced COPD patients. However, whether hypnosis could improve self-management of anxiety and dyspnoea in COPD during pulmonary rehabilitation is yet to be investigated.

This is the protocol for HYPNOBPCO_2, a 2-arm, cluster-randomised, statistician-blinded superiority monocentre trial (NCT04868357). Its aim is to assess the efficacy of hypnosis as a tool to manage anxiety and dyspnoea during a pulmonary rehabilitation programme (PRP). Clusters of COPD patients eligible for the conventional hospital-based PRP at the Centre Hospitalier de Bligny (CHB) will be randomised and evenly allocated into two parallel arms: “Hypnosis” (treatment) and “Relaxation” (active control). “Hypnosis” will consist of the CHB's conventional 4-week group PRP, supplemented by two educational sessions for teaching self-hypnosis. “Relaxation” will be identical, except standard relaxation exercises will be taught instead. Primary end-point will consist of assessing weekly changes in anxiety throughout the PRP, additional to total anxiety change after treatment completion. Anxiety will be determined by the six-item version of the State-Trait Anxiety Inventory (STAI-6). Secondary outcomes will include change in the 6-min walk test and the COPD assessment test (CAT). Further follow-up outcomes will include CAT and STAI-6 retests, re-hospitalisation rate, action plan use and persistence in self-hypnosis use, throughout the 12 weeks ensuing PRP completion.

Rationale for HYPNOBPCO_2 (NCT04868357), a trial investigating whether self-hypnosis (fast, low-cost, effortless) reliably improves breathlessness-related anxiety and breathing mechanics, during and after pulmonary rehabilitation in COPDhttps://bit.ly/3JF2vCW

Dyspnoea-12 and Multidimensional Dyspnea Profile: Systematic Review of Use and Properties

CONTEXT

The Dyspnoea-12 (D-12) and Multidimensional Dyspnea Profile (MDP) were specifically developed for assessment of multiple sensations of breathlessness.

OBJECTIVES

This systematic review aimed to identify the use and measurement properties of the D-12 and MDP across populations, settings and languages.

METHODS

Electronic databases were searched for primary studies (2008-2020) reporting use of the D-12 or MDP in adults. Two independent reviewers completed screening and data extraction. Study and participant characteristics, instrument use, reported scores and minimal clinical important differences (MCID) were evaluated. Data on internal consistency (Cronbach's α) and test-retest reliability (intraclass correlation coefficient, ICC) were pooled using random effects models between settings and languages.

RESULTS

A total 75 publications reported use of D-12 (n = 35), MDP (n = 37) or both (n = 3), reflecting 16 chronic conditions. Synthesis confirmed two factor structure, internal consistency (Cronbach's α mean, 95% CI: D-12 Total = 0.93, 0.91-0.94; MDP Immediate Perception [IP] = 0.88, 0.85-0.90; MDP Emotional Response [ER] = 0.86, 0.82-0.89) and 14 day test-rest reliability (ICC: D-12 Total = 0.91, 0.88-0.94; MDP IP = 0.85, 0.70-0.93; MDP ER = 0.84, 0.73-0.90) across settings and languages. MCID estimates for clinical interventions ranged between -3 and -6 points (D-12 Total) with small variability in scores over 2 weeks (D-12 Total 2.8 (95% CI: 2.0 to 3.7), MDP-A1 0.8 (0.6 to 1.1) and six months (D-12 Total 2.9 (2.0 to 3.7), MDP-A1 0.8 (0.6 to 1.1)).

CONCLUSION

D-12 and MDP are widely used, reliable, valid and responsive across various chronic conditions, settings and languages, and could be considered standard instruments for measuring dimensions of breathlessness in international trials.

Dyspnea

The clinical term dyspnea (a.k.a. breathlessness or shortness of breath) encompasses at least three qualitatively distinct sensations that warn of threats to breathing: air hunger, effort to breathe, and chest tightness. Air hunger is a primal homeostatic warning signal of insufficient alveolar ventilation that can produce fear and anxiety and severely impacts the lives of patients with cardiopulmonary, neuromuscular, psychological, and end-stage disease. The sense of effort to breathe informs of increased respiratory muscle activity and warns of potential impediments to breathing. Most frequently associated with bronchoconstriction, chest tightness may warn of airway inflammation and constriction through activation of airway sensory nerves. This chapter reviews human and functional brain imaging studies with comparison to pertinent neurorespiratory studies in animals to propose the interoceptive networks underlying each sensation. The neural origins of their distinct sensory and affective dimensions are discussed, and areas for future research are proposed. Despite dyspnea's clinical prevalence and impact, management of dyspnea languishes decades behind the treatment of pain. The neurophysiological bases of current therapeutic approaches are reviewed; however, a better understanding of the neural mechanisms of dyspnea may lead to development of novel therapies and improved patient care.

Linguistic Validation of the Japanese Version of the Multidimensional Dyspnea Profile and Relation to Physical Activity in Patients with COPD

Purpose

This study aimed to develop a linguistically validated Japanese translation of the multidimensional dyspnea profile (MDP) and assess whether worsening of dyspnea’s sensory and affective domains during exercise had detrimental effects on physical activity in stable outpatients with chronic obstructive pulmonary disease (COPD).

Materials and Methods

The Japanese version of the MDP was prepared in collaboration with Mapi Research Trust (Lyon, France) after the approval of the developer. Physical activity was assessed using a 3-axis accelerometer. Dyspnea upon exertion was investigated using a 3-minute step test.

Results

The Japanese version of the MDP was obtained and validated linguistically. Air-hunger was significantly associated with total calories from walking (r = − 0.47, p < 0.05), while anxiety and depression were significantly correlated with both the amount and intensity of physical activity (r = − 0.49, p < 0.05, and r = − 0.46, p < 0.05, respectively).

Conclusion

The Japanese version of the MDP was suggested to reflect both pulmonary functions, ventilatory response during exercise, and intensity and amount of physical activity in patients with COPD.

Clinical responses following inspiratory muscle training in exercise-induced laryngeal obstruction

Purpose

Exercise-induced laryngeal obstruction (EILO) is relatively common in young people. Treatment rests on poor evidence; however, inspiratory muscle training (IMT) has been proposed a promising strategy. We aimed to assess laryngeal outcomes shortly after IMT, and to compare self-reported symptoms with a control group 4–6 years later.

Methods

Two groups were retrospectively identified from the EILO-register at Haukeland University Hospital, Norway; one group had received only information and breathing advice (IBA), and another additionally IMT (IBA + IMT). At diagnosis, all participants performed continuous laryngoscopy during exercise (CLE), with findings split by glottic and supraglottic scores, and completed a questionnaire mapping exercise-related symptoms. After 2–4 weeks, the IBA + IMT-group was re-evaluated with CLE-test. After 4–6 years, both groups were re-assessed with a questionnaire.

Results

We identified 116 eligible patients from the EILO-register. Response rates after 4–6 years were 23/58 (40%) and 32/58 (55%) in the IBA and IBA + IMT-group, respectively. At diagnosis, both groups rated symptoms similarly, but laryngeal scores were higher in the IBA + IMT-group (P = 0.003). After 2–4 weeks, 23/32 in the IBA + IMT-group reported symptom improvements, associated with a decrease of mainly glottic scores (1.7–0.3; P < 0.001), contrasting unchanged scores in the 9/32 without symptom improvements. After 4–6 years, exercise-related symptoms and activity levels had decreased to similar levels in both groups, with no added benefit from IMT; however, full symptom resolution was reported by only 8/55 participants.

Conclusion

Self-reported EILO symptoms had improved after 4–6 years, irrespective of initial treatment. Full symptom resolution was rare, suggesting individual follow-up should be offered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00405-021-07214-5.

Prevalence and severity of differing dimensions of breathlessness among elderly males in the population

Breathlessness is common in the general population. Existing data were obtained primarily with the uni-dimensional modified Medical Research Council breathlessness scale (mMRC) that does not assess intensities of unpleasantness nor physical, emotional and affective dimensions. The aim of this research was to determine the prevalence and intensity of these dimensions of breathlessness in elderly males and any associations with their duration, change over time and mMRC grade.

We conducted a population-based, cross-sectional study of 73-year-old males in a county in southern Sweden. Breathlessness was self-reported at one time point using a postal survey including the Dyspnea-12 (D-12), the Multidimensional Dyspnea Profile (MDP) and the mMRC. Presence of an increased dimension score was defined as a score ≥minimal clinically important difference for each dimension scale. Association with the mMRC, recalled change since age 65, and duration of breathlessness were analysed with linear regression.

Among 907 men, an increased dimension score was present in 17% (D-12 total score), 33% (MDP A1 unpleasantness), 19% (D-12 physical), 17% (MDP immediate perception), 10% (D-12 affective) and 17% (MDP emotional response). The unpleasantness and affective dimensions were strongly associated with mMRC≥3. Higher MDP and D-12 scores were associated with worsening of breathlessness since age 65, and higher MDP A1 unpleasantness was associated with breathlessness of less than 1 year duration.

Increased scores of several dimensions of breathlessness are prevalent in 73-year-old males and are positively correlated with mMRC scores, worsening of breathlessness after age 65, and duration of less than 1 year.

This first epidemiological study of multidimensional breathlessness shows that unpleasant, physical, affective and emotional experiences of breathlessness are common among elderly males, and are strongly associated with mMRC ≥3https://bit.ly/3EThp5a

l-Menthol - a new treatment for breathlessness?

PURPOSE OF REVIEW

In patients with advanced chronic obstructive pulmonary disease (COPD), it is challenging to treat breathlessness. In addition, novel palliative interventions are required for multiple perspectives of breathlessness that may still be present after disease-specific therapies. This review provides an overview of the mechanisms and effects of l-menthol on breathlessness by covering the latest relevant papers.

RECENT FINDINGS

A literature review identified one randomized controlled trial assessing the effect of l-menthol on relieving breathlessness in patients with COPD. It has been reported that the mechanism of relieving breathlessness partly involves stimulation of the trigeminal nerve by the cooling sensation of l-menthol, which gives a cognitive illusion of inspiratory flow perception. The effect of l-menthol on breathlessness caused by exertion has been reported in healthy subjects but not yet in patients with breathlessness.

SUMMARY

The effect of l-menthol on the sensory-emotional dimensions of laboratory-induced breathlessness in patients with COPD has been described in a clinical trial. Further studies are warranted to investigate its application to inspiratory muscle training and its effects in combination with exercise training.

Feasibility of completing Multidimensional Dyspnea Profile and Dyspnea-12 over the telephone in patients with oxygen-dependent disease

Background

Breathlessness is prevalent in severe disease and consists of different dimensions that can be measured using the Multidimensional Dyspnea Profile (MDP) and Dyspnea-12 (D-12). We aimed to evaluate the feasibility of MDP and D-12 over telephone interviews in oxygen-dependent patients, compared with other patient-reported outcomes (modified Medical Research Council (mMRC) and Chronic Obstructive Pulmonary Disease Assessment Test (CAT)) and with completion by hand.

Methods

Cross-sectional, telephone study of 50 patients with home oxygen therapy. Feasibility was assessed as completion time (self-reported by patients and measured), difficulty (self-reported) and help required to complete the instruments (staff). Completion time was compared with mMRC and CAT, and feasibility was compared with completion by hand in cardiopulmonary outpatients (n=182). Feasibility by age and gender was analysed using logistic regression.

Results

Of 136 patients approached, 50 (37%) participated (mean age: 72±10 years, 66% women). Completion times (in minutes) were relatively short for MDP (self-reported 6 (IQR 5–10), measured 8 (IQR 6–10)) and D-12 (self-reported 5 (IQR 3–8), measured 3 (IQR 3–4)), and slightly longer than mMRC (median 1 (IQR 1–1)) and CAT (median 3 (IQR 2–5)). Even though the majority of patients required no help, more assistance was required by older patients. Compared with patients reporting by hand, completion over the telephone required somewhat longer time and more assistance.

Conclusion

Many patients with severe oxygen-dependent disease were unable or unwilling to assess symptoms over the telephone. However, among those able to participate, MDP and D-12 are feasible to measure multiple dimensions of breathlessness over the telephone.

Impact of inspiratory threshold loading on brain activity and cognitive performances in healthy humans

In healthy humans, inspiratory threshold loading deteriorates cognitive performances. This can result from motor-cognitive interference (activation of motor respiratory-related cortical networks vs. executive resources allocation), sensory-cognitive interference (dyspnea vs. shift in attentional focus), or both. We hypothesized that inspiratory loading would concomitantly induce dyspnea, activate motor respiratory-related cortical networks, and deteriorate cognitive performance. We reasoned that a concomitant activation of cortical networks and cognitive deterioration would be compatible with motor-cognitive interference, particularly in case of a predominant alteration of executive cognitive performances. Symmetrically, we reasoned that a predominant alteration of attention-depending performances would suggest sensory-cognitive interference. Twenty-five volunteers (12 men; 19.5-51.5 years) performed the Paced Auditory Serial Addition test (PASAT-A and B; calculation capacity, working memory, attention), the Trail Making Test (TMT-A, visuospatial exploration capacity; TMT-B, visuospatial exploration capacity and attention), and the Corsi block-tapping test (visuospatial memory, short-term and working memory) during unloaded breathing and inspiratory threshold loading in random order. Loading consistently induced dyspnea and respiratory-related brain activation. It was associated with deteriorations inPASAT A (52 [45.5;55.5] (median [interquartile range]) to 48 [41;54.5], p=0.01), PASAT B (55 [47.5;58] to 51 [44.5;57.5], p=0.01), and TMT B (44s [36;54.5] to 53s [42;64], p=0.01), but did not affect TMT-A and Corsi. The concomitance of cortical activation and cognitive performance deterioration is compatible with competition for cortical resources (motor-cognitive interference), while the profile of cognitive impairment (PASAT and TMT-B but not TMT-A and Corsi) is compatible with a contribution of attentional distraction (sensory-cognitive interference). Both mechanisms are therefore likely at play.

The role of personality traits in inpatient pulmonary rehabilitation response in patients with chronic obstructive pulmonary disease

BACKGROUND

The effectiveness of pulmonary rehabilitation (PR) is a critical issue for chronic obstructive pulmonary disease (COPD) patients. However, PR response is marked by a strong heterogeneity, partially unexplained to date. We hypothesized that personality traits defined by the Five-Factor Model could modulate the effect of inpatient-PR.

OBJECTIVE

The aim was to assess the associations between these five personality traits and PR outcomes.

METHODS

74 persons with COPD admitted for a 5-week inpatient PR program had a personality assessment at the start of the program (T1). Exercise capacity, quality of life, sensory and affective dyspnea dimensions were assessed at T1 and at the end of the program (T2). Their evolution was evaluated using the delta score between T2 and T1. PR response was defined using the minimal clinically important change score for each of them. A composite response was established distinguishing the poor responders' group, made of patients who responded to 0, 1 or 2 parameters and the good responders' group, with patients who responded on 3 or 4 indicators.

RESULTS

Logistic regressions analyses highlighted that those with a high level of openness [OR = 0.36, 95% CI = 0.15-0.74, p < 0.01] were less likely to respond on quality of life, controlling for socio-demographic factors and the severity of the disease.

CONCLUSION

This study shows that the investigation of the personality constitutes an interesting perspective for better understanding the interindividual differences observed between patients in the PR response. Tailoring clinical intervention to the patient's personality could be a promising prospect for optimizing PR effectiveness.

Dyspnea could be accurately assessed by a caregiver in hospitalized patients with respiratory diseases: Interrater reliability and agreement study

BACKGROUND

The perception of dyspnea is a subjective feeling typically self-assessed by the patient. However, the assessment by a caregiver is sometimes required.

OBJECTIVES

The primary aim was to compare patient self-assessment and caregiver assessment of dyspnea (interrater reliability) using the modified Borg and visual analog scale (VAS) in hospitalized patients. The secondary aim was to compare dyspnea assessment between the two scales for patients and caregiver (inter-instrument reliability).

METHODS

Self-assessment of dyspnea intensity of hospitalized patients with respiratory diseases was compared with caregiver's assessment. Dyspnea intensity was measured using two scales, the modified Borg scale (0-10 scale) and the 10 cm VAS. Mean difference and 95% confidence interval (CI) between assessors (i.e. patient versus caregiver) were calculated for each scale. Inter- and intra-rater reliability was calculated using intraclass correlation coefficients (ICCs).

RESULTS

A total of 254 patients were recruited. The mean differences between patient and caregiver ratings were 0.31 (95% CI: 0.09, 0.53) for the modified Borg scale and 0.36 (95% CI: 0.06, 0.65) for the VAS scale. Interrater reliability was good for both scales with ICC of 0.79 (95% CI: 0.73, 0.84) for VAS and 0.82 (95% CI: 0.77, 0.86) for the modified Borg scale. The mean differences in scores between scales were 0.93 (95% CI 0.69, 1.17) for patients' ratings and 0.88 (95% CI 0.72, 1.04) for caregiver's rating. The inter-instrument reliability was moderate to good and similar for both assessors.

CONCLUSION

Dyspnea can be accurately estimated by caregivers when patients with lung diseases cannot self-report. Scores on the VAS to rate dyspnea were higher than the scores on the Borg scale.

Case Studies in Physiology: Cardiopulmonary exercise testing and inspiratory muscle training in a 59-year-old, four years after an extra-pleural pneumonectomy

This case report characterizes the physiological responses to incremental cycling and determines the effects of 12 weeks of inspiratory muscle training (IMT) on respiratory muscle strength, exercise capacity and dyspnea in a physically active 59-year-old female, four years after a left-sided extra-pleural pneumonectomy (EPP). On separate days, a symptom limited incremental exercise test and a constant work rate (CWR) test at 75% of peak work rate (WR) were completed, followed by 12 weeks of IMT and another CWR test. IMT consisted of two sessions of 30 repetitions twice daily for 5 days per week. Physiological and perceptual variables were measured throughout each exercise test. The participant had a total lung capacity that was 43% predicted post-EPP. A rapid and shallow breathing pattern was adopted throughout exercise, and the ratio of minute ventilation to carbon dioxide output was elevated for a given work rate. Oxygen uptake was 74%predicted and WR was 88%predicted. Following IMT, maximal inspiratory pressure improved by 36% (-27.1 cmH₂O) and endurance time by 31s, with no observable changes in any submaximal or peak cardiorespiratory variables during exercise. The intensity and unpleasantness of dyspnea increased by 2 and 3 Borg 0-10 units, respectively, at the highest equivalent submaximal exercise time achieved on both tests. Despite having undergone a significant reduction in lung volume post-EPP, the participant achieved a relatively normal peak incremental WR, which may reflect a high level of physical conditioning. This case report also demonstrates that IMT can effectively increase respiratory muscle strength several years following EPP.

Randomised controlled trial to investigate the use of high-frequency airway oscillations as raining to mprove yspnoa (TIDe) in COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterised by symptomatic dyspnoea and reduced exercise tolerance, in part as a result muscle weakness, for which inspiratory muscle training (IMT) may be useful. Excess mucus hypersecretion commonly coexists in COPD and may lead to reduce ventilation, further impacting on breathlessness. Devices for sputum clearance may be employed to aid mucus expectoration. This trial aimed to explore the effectiveness of a combined IMT and high-frequency airway oscillating (HFAO) device in the management of dyspnoea.

METHODS

This was a double-blinded, randomised sham-controlled trial which recruited symptomatic patients with COPD. Patients were randomised to either a HFAO device (Aerosure) or sham device for 8 weeks, three times a day. The primary outcome was the Chronic Respiratory Questionnaire dyspnoea (CRQ-D) domain. Pre-specified subgroup analyses were performed including those with respiratory muscle weakness, excessive sputum and frequent exacerbators.

RESULTS

104 participants (68% men, mean (SD) age 69.75 years (7.41), forced expiratory volume in 1 s per cent predicted 48.22% (18.75)) were recruited to this study with 96 participants completing. No difference in CRQ-D was seen between groups (0·28, 95% CI -0.19 to 0.75, p=0.24), though meaningful improvements were seen over time in both groups (mean (SD) HFAO 0.45 (0.78), p<0.01; sham 0.73 (1.09), p<0.01). Maximal inspiratory pressure significantly improved in the HFAO group over sham (5.26, 95% CI 0.34 to 10.19, p=0.05). Similar patterns were seen in the subgroup analysis.

CONCLUSION

There were no statistical differences between the HFAO and the sham group in improving dyspnoea measured by the CRQ-D.

TRIAL REGISTRATION NUMBER

ISRCTN45695543.

Exertional multidimensional dyspnoea predicts exacerbation in stable outpatients with COPD

Dyspnoea is a risk factor for mortality in patients with chronic obstructive pulmonary disease (COPD) [1]. Awareness of the magnitude of respiratory drive to the respiratory muscles contributes to dyspnoea [2]. In line with this mechanism, elevated respiratory neural drive during hospitalisation and at hospital discharge, predicts readmission and mortality in patients with acute exacerbation of COPD [3, 4]. Furthermore, patients with COPD who experienced frequent exacerbations had heightened dyspnoea due to hypercapnia, compared with those with infrequent exacerbations [5]. Therefore, changes in the afferent and efferent loops involved in dyspnoea contribute to COPD exacerbations.

This study assessed the sensory and emotional aspects of breathlessness under the same exercise load in patients with COPD. Breathing discomfort with constant exercise predicted exacerbations within 1 year.https://bit.ly/3l2oA4A

Reliability and validity of the multidimensional dyspnea profile in hospitalized Chinese patients with respiratory diseases

Background:

Dyspnea is a multidimensional experience similar to pain and is one of the most common clinical presentations in patients with respiratory diseases. Accurately evaluating the experience of dyspnea allows nurses and physicians to deliver better medical services to patients. The multidimensional dyspnea profile emphasizes the psychosocial factors of dyspnea and assesses immediate discomfort, sensory qualities, and the emotional responses of patients with dyspnea. At present, the validity, reliability, and test–retest reliability of the multidimensional dyspnea profile in patients with respiratory diseases in China are unclear.

Objectives:

The aim of this study was to investigate the validity, reliability, and test–retest reliability of the Chinese version of the multidimensional dyspnea profile and to assess the convergent validity between the Chinese version of the multidimensional dyspnea profile and the modified Medical Research Council Dyspnea Scale.

Methods:

The factorial construct, intraclass correlations, internal consistency, and convergent validity of the Chinese version of the multidimensional dyspnea profile was evaluated using data from 231 inpatients with dyspnea from the respiratory department of a hospital. In the principal component analysis stage, 131 inpatients were evaluated. In the test–retest reliability analysis stage, 50 out of the 131 patients responded to the questionnaire again. In the confirmatory factor analysis, 100 inpatients from an independent sample were assessed.

Results:

The principal component analysis showed that the Chinese version of the multidimensional dyspnea profile had a two-factor structure: the immediate perceptual-related problem factor (6 items) and the emotional response-related problem factor (5 items). The convergent validity between the Chinese version of the multidimensional dyspnea profile and the modified Medical Research Council Dyspnea Scale was significant and acceptable based on the average variance extracted (r = .56, p < .001). The confirmatory factor analysis revealed a good model fit and provided support for the construct validity of the Chinese version of the multidimensional dyspnea profile. Overall, the internal consistency and intraclass correlation coefficient of the Chinese version of the multidimensional dyspnea profile were good.

Conclusion:

The 11-item Chinese version of the multidimensional dyspnea profile has acceptable validity and reliability in patients with respiratory diseases in China. In the future, more studies should be performed to further explore its clinical application.

Lifting dyspnoea invisibility: COVID-19 face masks, the experience of breathing discomfort, and improved lung health perception - a French nationwide survey

QUESTION ADDRESSED

In contrast with pain, dyspnoea is not visible to the general public who lack the corresponding experiential baggage. We tested the hypotheses that the generalised use of face masks to fight SARS-CoV2 dissemination could change this and sensitise people to respiratory health.

METHODS

General population polling (1012-person panel demographically representative of the adult French population -quota sampling method-; 517 women, 51%). 860 (85%) answered "no" to "treated for a chronic respiratory disease" ("respiratory healthy", RH) and 152 "yes" ("respiratory disease", RD). 14% of RH respondents reported having a close family member treated for a chronic respiratory disease (RH-family+ and RH-family-). Respondents described mask-related attitudes, beliefs, inconveniencies, dyspnoea, and changes in their respiratory health vision . RESULTS: Compliance with masks was high (94.7%). Dyspnoea ranked first among mask inconveniencies (RD 79.3%, RH 67.3%, p=0.013). "Air hunger" was the main sensory dyspnoea descriptor. Mask-related dyspnoea was independently associated with belonging to RH-family+ (Odds Ratio [OR] [95% confidence interval (CI)]: 1.85 [1.16-2.98]) and removing masks to improve breathing (OR 5.21 [3.73-7.28]). It was negatively associated with considering masks effective to protect others (OR]: 0.42 [0.25-0.75]). Half the respondents were more concerned with their respiratory health since wearing masks; 41% reported better understanding patients' experiences.

ANSWER TO THE QUESTION

Wearing protective face masks leads to the mass discovery of breathing discomfort. It raises the public's awareness of what respiratory diseases involve and sensitises to the importance of breathing. These data should be used as the fulcrum of respiratory-health-oriented communication actions.

'Scared to death' dyspnoea from the hospitalised patient's perspective

Because dyspnoea is seldom experienced by healthy people, it can be hard for clinicians and researchers to comprehend the patient’s experience. We collected patients’ descriptions of dyspnoea in their own words during a parent study in which 156 hospitalised patients completed a quantitative multidimensional dyspnoea questionnaire. These volunteered comments describe the severity and wide range of experiences associated with dyspnoea and its impacts on a patients’ life. They provide insights not conveyed by structured rating scales. We organised these comments into the most prominent themes, which included sensory experiences, emotional responses, self-blame and precipitating events. Patients often mentioned air hunger (‘Not being able to get air is the worst thing that could ever happen to you.’), anxiety, and fear (‘Scared. I thought the world was going to end, like in a box.’). Their value in patient care is suggested by one subject’s comment: ‘They should have doctors experience these symptoms, especially dyspnoea, so they understand what patients are going through.’ Patients’ own words can help to bridge this gap of understanding.

Comparison between tools for measuring breathlessness: Cross-sectional validation of the Japanese version of the Dyspnoea-12

INTRODUCTION

The Dyspnoea-12 (D-12) is a brief, easy to complete questionnaire for measuring breathlessness.

OBJECTIVES

To facilitate further efforts to measure dyspnoea in real clinical settings, the authors aimed to develop and validate a Japanese version of the D-12 and also compare the D-12 with the Baseline Dyspnea Index (BDI) and the Activity component of the St. George's Respiratory Questionnaire (SGRQ).

METHODS

The standardized procedure in accordance with international guidelines was used to create the translation. A validation study with a cross-sectional observational design was conducted on 122 subjects with stable chronic obstructive pulmonary disease (COPD).

RESULTS

The internal consistency of the D-12 was high (Cronbach's coefficient α = 0.883) and similar to that of the BDI (α = 0.824) and SGRQ Activity (α = 0.872). The relationships between tools were statistically significant (|R_s | = 0.53 to 0.66). Although the scores obtained from all three tools were skewed toward the milder end of the respective scales, this deviation was most prominent in the D-12 with a floor effect of 48.4%.

CONCLUSION

The Japanese version of the D-12 was successfully validated, but we should be careful of any floor effect and marked skew to the mild end of the scale, especially in subjects with mild COPD.

Management of respiratory distress following prehospital implementation of noninvasive ventilation in a physician-staffed emergency medical service: a single-center retrospective study

BACKGROUND

Noninvasive ventilation (NIV) is recognized as first line ventilatory support for the management of acute pulmonary edema (APE) and chronic obstructive pulmonary disease (COPD) exacerbations. We aimed to study the prehospital management of patients in acute respiratory distress with an indication for NIV and whether they received it or not.

METHODS

This retrospective study included patients ≥18 years old who were cared for acute respiratory distress in a prehospital setting. Indications for NIV were oxygen saturation (SpO₂) <90% and/or respiratory rate (RR) >25/min with a presumptive diagnosis of APE or COPD exacerbation. Study population characteristics, initial and at hospital vital signs, presumptive and definitive diagnosis were analyzed. For patients who received NIV, dyspnea level was evaluated with a dyspnea verbal ordinal scale (D-VOS, 0-10) and arterial blood gas (ABG) values were obtained at hospital arrival.

RESULTS

Among the 187 consecutive patients included in the study, most (n = 105, 56%) had experienced APE or COPD exacerbation, and 56 (30%) received NIV. In comparison with patients without NIV, those treated with NIV had a higher initial RR (35 ± 8/min vs 29 ± 10/min, p < 0.0001) and a lower SpO₂ (79 ± 10 vs 88 ± 11, p < 0.0001). The level of dyspnea was significantly reduced for patients treated with NIV (on-scene D-VOS 8.4 ± 1.7 vs 4.4 ± 1.8 at admission, p < 0.0001). Among the 131 patients not treated with NIV, 41 (31%) had an indication. In the latter group, initial SpO₂ was 80 ± 10% in the NIV group versus 86 ± 11% in the non-NIV group (p = 0.0006). NIV was interrupted in 9 (16%) patients due to either discomfort (n = 5), technical problem (n = 2), persistent desaturation (n = 1), or vomiting (n = 1).

CONCLUSIONS

The results of this study contribute to a better understanding of the prehospital management of patients who present with acute respiratory distress and an indication for NIV. NIV was started on clinically more severe patients, even if predefined criteria to start NIV were present. NIV allows to improve vital signs and D-VOS in those patients. A prospective study could further elucidate why patients with a suspected diagnosis of APE and COPD are not treated with NIV, as well as the clinical impact of the different strategies.

TRIAL REGISTRATION

The study was approved by our institutional ethical committee ( CER-VD 2020-01363 ).

How to Assess Breathlessness in Chronic Obstructive Pulmonary Disease

Activity-related breathlessness is the most problematic symptom of chronic obstructive pulmonary disease (COPD), arising from complex interactions between peripheral pathophysiology (both pulmonary and non-pulmonary) and central perceptual processing. To capture information on the breathlessness experienced by people with COPD, many different instruments exist, which vary in applicability depending on the purpose and context of assessment. We reviewed common breathlessness assessment instruments, providing recommendations around how to assess the severity of, or change in, breathlessness in people with COPD in daily life or in response to exercise provocation. A summary of 14 instruments for the assessment of breathlessness severity in daily life is presented, with 11/14 (79%) instruments having established minimal clinically importance differences (MCIDs) to assess and interpret breathlessness change. Instruments varied in their scope of assessment (functional impact of breathlessness or the severity of breathlessness during different activities, focal periods, or alongside other common COPD symptoms), dimensions of breathlessness assessed (uni-/multidimensional), rating scale properties and intended method of administration (self-administered versus interviewer led). Assessing breathlessness in response to an acute exercise provocation overcomes some limitations of daily life assessment, such as recall bias and lack of standardized exertional stimulus. To assess the severity of breathlessness in response to an acute exercise provocation, unidimensional or multidimensional instruments are available. Borg's 0-10 category rating scale is the most widely used instrument and has estimates for a MCID during exercise. When assessing the severity of breathlessness during exercise, measures should be taken at a standardized submaximal point, whether during laboratory-based tests like cardiopulmonary exercise testing or field-based tests, such as the 3-min constant rate stair stepping or shuttle walking tests. Recommendations are provided around which instruments to use for breathlessness assessment in daily life and in relation to exertion in people with COPD.

Breathlessness in COPD: linking symptom clusters with brain activity

Background

Current models of breathlessness often fail to explain disparities between patients' experiences of breathlessness and objective measures of lung function. While a mechanistic understanding of this discordance has thus far remained elusive, factors such as mood, attention and expectation have all been implicated as important modulators of breathlessness. Therefore, we have developed a model to better understand the relationships between these factors using unsupervised machine learning techniques. Subsequently we examined how expectation-related brain activity differed between these symptom-defined clusters of participants.

Methods

A cohort of 91 participants with mild-to-moderate chronic obstructive pulmonary disease (COPD) underwent functional brain imaging, self-report questionnaires and clinical measures of respiratory function. Unsupervised machine learning techniques of exploratory factor analysis and hierarchical cluster modelling were used to model brain–behaviour–breathlessness links.

Results

We successfully stratified participants across four key factors corresponding to mood, symptom burden and two capability measures. Two key groups resulted from this stratification, corresponding to high and low symptom burden. Compared with the high symptom burden group, the low symptom burden group demonstrated significantly greater brain activity within the anterior insula, a key region thought to be involved in monitoring internal bodily sensations (interoception).

Conclusions

This is the largest functional neuroimaging study of COPD to date, and is the first to provide a clear model linking brain, behaviour and breathlessness expectation. Furthermore, it was possible to stratify participants into groups, which then revealed differences in brain activity patterns. Together, these findings highlight the value of multimodal models of breathlessness in identifying behavioural phenotypes and for advancing understanding of differences in breathlessness burden.

Towards individualised treatments for chronic breathlessness with functional neuroimaging: revealing the factors underlying the breathlessness experience in COPDhttps://bit.ly/3a8fXPt

Validity and reliability of the Multidimensional Dyspnoea Profile in older adults

Breathlessness is a common and distressing symptom in older adults and an independent predictor of adverse outcomes and yet its multidimensional assessment has not been validated in older adults. We apply and validate the Multidimensional Dyspnoea Profile (MDP) in a sample of adults 75 years and older in Belgium.

Breathlessness was rated with the MDP, the modified Borg Dyspnoea Scale (mBDS), the Short Physical Performance Battery (SPPB, a numerical rating scale for intensity and unpleasantness both before and after exertion), as well as with the Medical Research Council (MRC) Dyspnoea Scale. The Hospital Anxiety and Depression Scale (HADS) assessed the affective status. Factor structure was analysed with exploratory principal components analysis, internal consistency with Cronbach's alpha and concurrent validity with Spearman's correlation coefficients with other breathlessness scales, HADS and SPPB scores.

In 96 participants (mean age 85 years; 34% men) who rated breathlessness at both assessment points, exploratory principal components analysis identified two components: Immediate Perception (IP) and Emotional Reaction (ER), explaining most of the MDP item variance (65.37% before and 71.32% after exertion). Internal consistency was moderate to high for MDP-IP (Cronbach's alpha = 0.86 before and 0.89 after exertion) and MDP-ER (Cronbach's alpha = 0.89 before and 0.91 after exertion). The correlation patterns of MDP-IP and MDP-ER with other tests confirmed concurrent validity.

The domain structure, reliability and concurrent validity of MDP for breathlessness before and after exertion were confirmed in a sample of adults 75 years and older, supporting its use and further research for the multidimensional profiling of breathlessness in older adults.

Domain structure, reliability and concurrent validity of the MDP were confirmed in a sample of adults aged ≥75 years before and after exertion, supporting its use for the multidimensional assessment of breathlessness in this age grouphttps://bit.ly/3emiNRW

A common model for the breathlessness experience across cardiorespiratory disease

Chronic breathlessness occurs across many different conditions, often independently of disease severity. Yet, despite being strongly linked to adverse outcomes, the consideration of chronic breathlessness as a stand-alone therapeutic target remains limited. Here we use data-driven techniques to identify and confirm the stability of underlying features (factors) driving breathlessness across different cardiorespiratory diseases. Questionnaire data on 182 participants with main diagnoses of asthma (21.4%), COPD (24.7%), heart failure (19.2%), idiopathic pulmonary fibrosis (18.7%), other interstitial lung disease (2.7%), and "other diagnoses" (13.2%) were entered into an exploratory factor analysis (EFA). Participants were stratified based on their EFA factor scores. We then examined model stability using 6-month follow-up data and established the most compact set of measures describing the breathlessness experience. In this dataset, we have identified four stable factors that underlie the experience of breathlessness. These factors were assigned the following descriptive labels: 1) body burden, 2) affect/mood, 3) breathing burden and 4) anger/frustration. Stratifying patients by their scores across the four factors revealed two groups corresponding to high and low burden. These two groups were not related to the primary disease diagnosis and remained stable after 6 months. In this work, we identified and confirmed the stability of underlying features of breathlessness. Previous work in this domain has been largely limited to single-diagnosis patient groups without subsequent re-testing of model stability. This work provides further evidence supporting disease independent approaches to assess breathlessness.

A Conceptual Framework for Understanding Speaking Dyspnea

Purpose A conceptual framework is proposed to better understand the experience of people who have dyspnea (breathing discomfort) when speaking: its nature, its physiological mechanisms, and its impacts on their lives. Method The components of the framework are presented in their natural order. They are a Speaking Domain (Speaking Activities and Speaking Variables), a Physiological Domain (Speech Breathing Variables and Physiological Mechanisms), a Perceptual Domain (Dyspnea), a Symptom Impact Domain (Emotional Responses, Immediate Behavioral Responses, and Long-Term Behavioral Response), and a Life Impact Domain (Short-Term Impacts and Long-Term Impacts). Results We discuss literature that most directly supports these components and includes findings from healthy people and those with disorders in whom speaking dyspnea was either evoked or measured. Caveats are noted where information is limited and further study is needed. A case example is provided to illustrate how to apply the framework. Conclusions This framework provides a broader view of the elements that contribute to the experience of speaking dyspnea. It is meant to guide researchers, clinicians, instructors, caregivers, and those for whom speaking dyspnea is a daily or even a life-long challenge.

Effects of Sarcopenia on Ventilatory Behavior and the Multidimensional Nature of Dyspnea in Patients With Chronic Obstructive Pulmonary Disease

OBJECTIVES

This study tested the hypothesis that sarcopenia, a common extrapulmonary feature of chronic obstructive pulmonary disease (COPD), can affect ventilatory behavior, and worsen the multidimensional nature of dyspnea in patients with COPD.

DESIGN

Cross-sectional survey study.

SETTING

and Participants: Stable outpatients with COPD encountered in general practice and respiratory clinic.

METHOD

Sarcopenia was diagnosed according to an appendicular skeletal muscle mass index based on measurements of electrical impedance and handgrip strength. Exertional dyspnea was tested using a 3-minute Step Test and a 6-minute Walk Test. The dimensions of dyspnea were assessed by a multidimensional dyspnea profile.

RESULTS

Of 60 stable patients with COPD, 16 met the criteria for sarcopenia. During the 3-minute Step Test, minute ventilation as a proportion of exercise time, tidal volume as a proportion of inspiratory capacity, the change in inspiratory capacity, and ventilation as a proportion of maximal voluntary ventilation did not differ between patients with and without sarcopenia. Patients with sarcopenia exhibited lower evolution of tidal volume, higher evolution of respiratory frequency versus ventilation and breathing discomfort on the 3-minute Step Test, as well as increased physical breathing effort on the 6-minute Walk Test, compared with those without sarcopenia. In a multivariable model adjusted using inverse probability weighting, sarcopenia was independently associated with breathing discomfort during the 3-minute Step Test and physical breathing effort during the 6-minute Walk Test.

CONCLUSIONS AND IMPLICATIONS

Sarcopenia may be associated with shallow breathing and diverse sensory and affective components of exertional dyspnea in patients with COPD. The study indicates that improvement of the rapid breathing pattern may offer unique ways to alleviate dyspnea in older patients with COPD and sarcopenia.

Air Hunger: A Primal Sensation and a Primary Element of Dyspnea

The sensation that develops as a long breath hold continues is what this article is about. We term this sensation of an urge to breathe "air hunger." Air hunger, a primal sensation, alerts us to a failure to meet an urgent homeostatic need maintaining gas exchange. Anxiety, frustration, and fear evoked by air hunger motivate behavioral actions to address the failure. The unpleasantness and emotional consequences of air hunger make it the most debilitating component of clinical dyspnea, a symptom associated with respiratory, cardiovascular, and metabolic diseases. In most clinical populations studied, air hunger is the predominant form of dyspnea (colloquially, shortness of breath). Most experimental subjects can reliably quantify air hunger using rating scales, that is, there is a consistent relationship between stimulus and rating. Stimuli that increase air hunger include hypercapnia, hypoxia, exercise, and acidosis; tidal expansion of the lungs reduces air hunger. Thus, the defining experimental paradigm to evoke air hunger is to elevate the drive to breathe while mechanically restricting ventilation. Functional brain imaging studies have shown that air hunger activates the insular cortex (an integration center for perceptions related to homeostasis, including pain, food hunger, and thirst), as well as limbic structures involved with anxiety and fear. Although much has been learned about air hunger in the past few decades, much remains to be discovered, such as an accepted method to quantify air hunger in nonhuman animals, fundamental questions about neural mechanisms, and adequate and safe methods to mitigate air hunger in clinical situations. © 2021 American Physiological Society. Compr Physiol 11:1449-1483, 2021.

Validity and reliability of the Turkish version of the Multidimensional Dyspnea Profile in outpatients with respiratory disease

Background/aim

Dyspnea is the subjective feeling of breathing discomfort, which is a significant problem for patients with heart and respiratory disease and also an important determinant of exercise tolerance, quality of life, and mortality in various diseases. Most of the scales are not enough to investigate the multidimensional effects of dyspnea; therefore, the Multidimensional Dyspnea Profile (MDP) was developed and validated in many languages. This study aimed to translate and culturally adapt the MDP into Turkish and investigate the psychometric properties of this adapted version in outpatients with respiratory disease.

Materials and methods

The MDP was translated and culturally adapted into Turkish following published guidelines. A total of 170 outpatients with respiratory disease were included to assess psychometric properties. The factorial structure was investigated using a principal component analysis. Two situations were used in this study evaluating dyspnea in activity-related and resting conditions. We formulated 17 hypotheses for each MDP domain (in total 68) to assess construct validity, and correlations were investigated between the MDP and measures of body mass index, pulmonary function test, other dyspnea assessments, anxiety, depression, and health-related quality of life. To investigate the test-retest reliability, the MDP was administered again after 1-h and 1 week.

Results

Internal consistency of the MDP was excellent (Cronbach’s alpha coefficients ranged from 0.89 to 0.93). The exploratory factor analysis revealed 2 components explaining a 70% and 76% variance. Overall, 64 of the 68 predetermined hypotheses (94%) were confirmed to test construct validity. The MDP showed excellent test-retest reliability for a 1-hperiod (intraclass correlation coefficient values ranged from 0.98 to 0.99). However, test-retest reliability decreased moderate-to-high after 1 week (0.53–0.80).

Conclusion

The MDP was successfully translated and culturally adapted into Turkish and this version showed good psychometric properties including the factorial structure, internal consistency, test-retest reliability, and construct validity to assess multidimensional aspects of dyspnea.