Multidimensional Dyspnea Research Articles

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

Dyspnea is a common and debilitating symptom that affects many different patient populations. Dyspnea measures should assess multiple domains. To evaluate the reliability, validity, and responsiveness of an ultra-brief, multi-dimensional dyspnea measure. 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). We used data from a multi-site randomized clinical trial among outpatients with heart failure. 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. 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. 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.

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

PurposeThis 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 MethodsThe 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.ResultsThe 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).ConclusionThe 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.

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.

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

BackgroundBreathlessness 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...

Breathlessness dimensions association with physical and mental quality of life: the population based VASCOL study of elderly men

BackgroundBreathlessness is a multidimensional symptom prevalent in elderly affecting many aspects of life. We aimed to determine how different dimensions of breathlessness are associated with physical and mental quality of...

Exertional multidimensional dyspnoea predicts exacerbation in stable outpatients with COPD.

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

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

ObjectivesThis 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. DesignCross-sectional survey study. Settingand Participants: Stable outpatients with COPD encountered in general practice and respiratory clinic. MethodSarcopenia 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. ResultsOf 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 ImplicationsSarcopenia 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.

‘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...

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.

Danish translation and linguistic validation of the multidimensional dyspnea profile

The World Health Organization (WHO)estimates that approximately 21,8 million people annually die due to cardio-pulmonary diseases[1]. Dyspnea is prevalent in cardio-pulmonary diseases [2], and ofte...

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

Background/aimDyspnea 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 methodsThe 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.ResultsInternal 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).ConclusionThe 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.

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.

Buccal Hydromorphone Syrup for Managing Dyspnea in Idiopathic Pulmonary Fibrosis.

Dyspnea is a highly distressing symptom that characterizes idiopathic pulmonary fibrosis (IPF), a common idiopathic interstitial lung disease (ILD) with a high symptom burden, poor quality of life, and early mortality. Though opioids are mentioned in guidelines for dyspnea management, guidance on how and when to initiate opioids is lacking. Different pharmacologic strategies are needed to address different types of dyspnea (baseline, incident, and crisis). Due to a longer onset of action, the oral route (swallowed) may be less effective for prevention of incident dyspnea or for rapid relief of crisis dyspnea, prompting the use of alternative drug delivery strategies for self-management. We inadvertently discovered the efficacy of buccal administration of low dose, low volume hydromorphone oral syrup for dyspnea management in ILD, which has not been previously reported in the literature. We describe our approach to dyspnea assessment and management in IPF, including use of the Multidimensional Dyspnea Scale (MDDS), a novel instrument yet to be validated that we developed to better identify and categorize dyspnea into the types experienced by a patient with IPF over the course of a day. We then describe how buccal hydromorphone oral syrup is initiated and titrated for dyspnea management in 3 patients at different points in their disease trajectory. Buccal hydromorphone oral syrup is effective for dyspnea management across the spectrum of IPF. When integrated into a patient-centered algorithm for symptom assessment and management, it allows for rapid and easy self-management of dyspnea by patients and their caregivers.

RESPONSIVENESS OF THE DYSPNEA MANAGEMENT QUESTIONNAIRE COMPUTER ADAPTIVE TEST (DMQ-CAT) FOLLOWING PULMONARY REHABILITATION

SESSION TITLE: Pulmonary Rehabilitation Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: The Dyspnea Management Questionnaire Computer Adaptive Test (DMQ-CAT) is a recently developed dyspnea patient-reported outcome measure for adults with chronic obstructive pulmonary disease (COPD). The study purpose was to establish the responsiveness and minimal detectable change (MDC) of the DMQ-CAT. METHODS: A prospective, multicenter observational study of 90 subjects with COPD, with repeated measures before and after outpatient pulmonary rehabilitation (PR), was conducted. Subjects’ mean ±SD of forced expiratory volume in 1 second was 50.49±17.63% predicted (n=84). Data were collected at three outpatient PR centers; PR programs had durations between 8 and 12 weeks. The DMQ-CAT, Chronic Respiratory Questionnaire (CRQ), modified Medical Research Council scale (mMRC), Borg scale (0–10), and University of California, San Diego Shortness of Breath Questionnaire (UCSD) were concurrently administered to compare responsiveness. Previously established test-retest reliability coefficients for dyspnea measures were used to calculate the MDC at the 90% confidence interval (MDC-90). RESULTS: DMQ-CAT scale change scores correlated significantly with change scores of the CRQ and UCSD (r=0.3–0.58). The DMQ-CAT demonstrated comparable responsiveness to change relative to other widely used dyspnea measures. There were no statistically significant differences in effect sizes across instruments. The effect sizes (95% CI) of PR using the DMQ-CAT were 0.67 (0.44,0.96) for Anxiety, 0.63 (0.41,0.91) for Activity Avoidance, 0.64 (0.42,0.88) for Intensity, and 0.60 (0.37,0.88) for Self-efficacy. PR effect sizes using comparison measures were 0.51–0.75 for CRQ, -0.45 for mMRC, -0.42 for Borg, and -0.59 for UCSD. Standard error of measurement (SEM) for DMQ-CAT were 1.99 for Anxiety, 1.73 for Activity Avoidance, 3.21 for Intensity, and 3.56 for Self-efficacy. Distribution-based MDC-90 threshold values of the DMQ-CAT were 4.6 for Anxiety, 4.0 for Activity Avoidance, 7.5 for Intensity, and 8.3 for Self-efficacy. CONCLUSIONS: Results support the responsiveness of the DMQ-CAT for use in both COPD clinical trials and clinical practice to measure multidimensional dyspnea improvement outcomes. The DMQ-CAT is as responsive to pulmonary rehabilitation gains as other widely used dyspnea and quality of life measures. CLINICAL IMPLICATIONS: Newly estimated, distribution-based SEM and MDC-90 can be used to interpret DMQ-CAT outcome scores to determine if the magnitude of changes are beyond measurement error. The selection of a dyspnea outcome measure as a primary endpoint in PR clinical trials depends on the dyspnea domain of interest and hypothesized treatment mechanism(s). DISCLOSURES: Consultant relationship with GlaxoSmithKline Please note: $5001 - $20000 by Ravi Kalhan, source=Admin input, value=Consulting fee Speaker/Speaker's Bureau relationship with GlaxoSmithKline Please note: $5001 - $20000 by Ravi Kalhan, source=Admin input, value=Royalty Consultant relationship with Boehringer Ingelheim Please note: $5001 - $20000 by Ravi Kalhan, source=Admin input, value=Consulting fee Consultant relationship with AstraZeneca Please note: $5001 - $20000 by Ravi Kalhan, source=Admin input, value=Consulting fee Consultant relationship with Boston Scientific Please note: $5001 - $20000 by Ravi Kalhan, source=Admin input, value=Consulting fee Advisory Committee Member relationship with Pfizer Please note: $20001 - $100000 Added 02/14/2020 by Elizabeth Klings, source=Web Response, value=Grant/Research Support Advisory Committee Member relationship with Micelle Please note: $1001 - $5000 Added 02/14/2020 by Elizabeth Klings, source=Web Response, value=Consulting fee Site PI for clinical trial relationship with Bayer Please note: $5001 - $20000 Added 02/14/2020 by Elizabeth Klings, source=Web Response, value=Grant/Research Support Site PI for clinical trial relationship with Actelion Please note: $5001 - $20000 Added 02/14/2020 by Elizabeth Klings, source=Web Response, value=Grant/Research Support Site PI for clinical trial relationship with Reata Please note: $5001 - $20000 Added 02/14/2020 by Elizabeth Klings, source=Web Response, value=Grant/Research Support site PI for clinical trial relationship with Arena/United Therapeutics Please note: $5001 - $20000 Added 02/14/2020 by Elizabeth Klings, source=Web Response, value=Grant/Research Support Research support relationship with Novartis Please note: $5001 - $20000 Added 07/10/2020 by Elizabeth Klings, source=Web Response, value=Consulting fee No relevant relationships by Kyle MacDonald, source=Web Response No relevant relationships by Pengsheng Ni, source=Web Response No relevant relationships by Anna Norweg, source=Web Response No relevant relationships by Jonathan Whiteson, source=Web Response

A multidimensional assessment of dyspnoea in healthy adults during exercise.

(1) To determine whether healthy humans can distinguish between the intensity and unpleasantness of exertional dyspnoea; (2) to evaluate the reliability of qualitative dyspnoea descriptors during exercise; and (3) to assess the reliability of the Multidimensional Dyspnoea Profile (MDP) METHODS: Forty-four healthy participants (24M:20F, 25 ± 5years) completed maximal incremental cycling tests on three visits. During visit 1, participants rated the intensity and unpleasantness of dyspnoea simultaneously throughout exercise using the modified 0-10 category-ratio Borg scale. On visits 2 and 3, participants rated either the intensity or unpleasantness of dyspnoea alone at the same measurement times as visit 1. On all visits, participants selected qualitative descriptors throughout all exercise intensities from a list of 4, selected relevant qualitative descriptors from a list of 15 at peak exercise, and completed the MDP. Participants rated their dyspnoea intensity significantly higher for a given minute ventilation ([Formula: see text]) compared to dyspnoea unpleasantness (dyspnoea-[Formula: see text] slope: 0.08 ± 0.02 vs. 0.07 ± 0.03 Borg 0-10/Lmin-1, p < 0.001) during visit 1. The onset of intensity ratings occurred at a significantly lower work rate compared to unpleasantness ratings measured on the same exercise test (52 ± 41 vs. 91 ± 53 watts, p < 0.001). Dyspnoea intensity and unpleasantness remained significantly different for a given ventilation even when measured independently on separate exercise tests (p < 0.05). There was good-to-excellent reliability (ICC > 0.60) for the use of qualitative dyspnoea descriptors and the MDP to measure dyspnoea at peak exercise. Exercise-induced dyspnoea in healthy adults can differ in the sensory and affective dimensions, and can be measured reliably using qualitative descriptors and the MDP.

Episodic Breathlessness with and without Background Dyspnea in Advanced Cancer Patients Admitted to an Acute Supportive Care Unit.

Aim: To characterize episodic breathlessness (EB) in patients with advanced cancer, and to determine factors influencing its clinical appearance. Methods: A consecutive sample of advanced cancer patients admitted to an acute palliative care unit was surveyed. Continuous dyspnea and EB were measured by a numerical scale. The use of drugs used for continuous dyspnea and EB was recorded. Patients were asked about the characteristics of EB (frequency, intensity, duration and triggers). The Multidimensional dyspnea profile (MDP), the Brief dyspnea inventory (BDI), the Athens sleep scale (AIS) and the Hospital Anxiety and Depression Scale (HADS) were also administered. Results: From 439 advanced cancer patients surveyed, 34 and 27 patients had EB, without and with background dyspnea, respectively. The mean intensity and the number of episodes were higher in patients with background dyspnea (p < 0.0005 and p = 0.05, respectively). No differences in duration were observed. Most episodes lasted <10 min. A recognizable cause triggering EB was often found. The presence of both background dyspnea and EB was associated with higher values of MDP and BDI. EB was independently associated with frequency and intensity of background dyspnea (OR = 20.9, 95% CI (Confidence interval) 9.1–48.0; p < 0.0005 and OR = 1.97, 95% CI 1.09–3.58; p = 0.025, respectively) and a lower Karnofsky level (OR = 0.96, 95%CI 0.92–0.98, p = 0.05). Discussion: EB may occur in patients with and without continuous dyspnea, and is often induced by physical and psychological factors. EB intensity is higher in patients with continuous dyspnea. The duration was often so short that the use of drugs, as needed, may be too late, unless administered pre-emptively when the trigger was predictable.

The effect of diaphragm fatigue on the multidimensional components of dyspnoea and diaphragm electromyography during exercise in healthy males

Diaphragm fatigue may increase the intensity (sensory dimension) and unpleasantness (affective dimension) of dyspnoea, which may partially explain why diaphragm fatigue negatively affects exercise performance. We hypothesized that diaphragm fatigue would negatively affect exercise performance via increases in both the intensity and unpleasantness of dyspnoea, and that the increase in dyspnoea would be mechanistically linked to an increase in diaphragmatic EMG (EMGdi ), a surrogate measure of neural respiratory drive. Fatiguing the diaphragm prior to exercise reduced cycling performance and increased both the intensity and unpleasantness of dyspnoea. The change in submaximal dyspnoea unpleasantness was significantly correlated with the change in cycling performance. Pre-fatigue of the diaphragm did not increase EMGdi during exercise and is therefore unrelated to the increase in either the sensory or affective dimension of exertional dyspnoea. The purpose of this study was to examine the effect of diaphragm fatigue on the multidimensional components of dyspnoea and diaphragm electromyography (EMGdi ) during cycling. Sixteen healthy males (age=27±5yr, =45.8±9.8mlkg-1 min-1 ) completed two high-intensity, time-to-exhaustion cycling tests in randomized order: (i) inspiratory pressure threshold loading (PTL) prior to exercise to induce diaphragm fatigue (pre-DF) and (ii) no PTL (control). Diaphragm fatigue after PTL was confirmed via cervical magnetic stimulation of the phrenic nerves. Dyspnoea intensity and unpleasantness were measured throughout exercise with the 0-10 category-ratio Borg scale and following exercise using the Multidimensional Dyspnoea Profile (MDP). EMGdi was continuously recorded via a multipair oesophageal electrode catheter. Time-to-exhaustion decreased with pre-DF vs. control (9.0±5.5 vs. 10.7±7.5min, P=0.023). Pre-DF increased dyspnoea intensity ratings by 0.6±1.0 Borg 0-10 units at the highest equivalent submaximal exercise time (HESET) a participant could achieve in both conditions (P=0.020). Dyspnoea unpleasantness ratings increased with pre-DF by 0.5±1.0, 0.7±1.2 and 0.9±1.4 (all P<0.05) Borg 0-10 units during the 2nd, 3rd and 4th minutes of exercise, respectively. There was a significant correlation between the change in breathing unpleasantness ratings at HESET and the change in time-to-exhaustion (r=0.66, P=0.006). The immediate perception domain, a combination of peak unpleasantness and specific dyspnoea descriptor intensity ratings, was the only component of the MDP that was significantly increased with pre-DF (4.3±1.9 vs. 3.6±1.8, P=0.04). There were no significant differences in EMGdi . In conclusion, diaphragm fatigue has negative effects on multiple domains of dyspnoea, which may partially explain why exercise performance decreases with it.

Minimal Clinically Important Differences and Feasibility of Dyspnea-12 and the Multidimensional Dyspnea Profile in Cardiorespiratory Disease

ContextBreathlessness is a cardinal symptom in cardiorespiratory disease and consists of multiple dimensions that can be measured using the instruments Dyspnea-12 (D12) and the Multidimensional Dyspnea Profile (MDP). ObjectivesThe objective of the study is to determine the minimal clinically important differences (MCIDs) of all D12 and MDP summary and subdomain scores as well as the instruments' feasibility in patients with cardiorespiratory disease. MethodsProspective multicenter cohort study of outpatients with diagnosed cardiorespiratory disease and breathlessness in daily life. D12 and MDP were assessed at baseline, after 30–90 minutes and two weeks. MCIDs were calculated using anchor-based and distributional methods for summary and subdomain scores. Feasibility was assessed as rate of missing data, help required, self-reported difficulty, and completion time. ResultsA total 182 outpatients (53.3% women) were included; main diagnoses were chronic obstructive pulmonary disease (COPD; 25%), asthma (21%), heart failure (19%), and idiopathic pulmonary fibrosis (19%). Anchor-based MCIDs were for D12 total score 2.83 (95% CI 1.99–3.66); D12 physical 1.81 (1.29–2.34); D12 affective 1.07 (0.64–1.49); MDP A1 unpleasantness 0.82 (0.56–1.08); MDP perception 4.63 (3.21–6.05), and MDP emotional score 2.37 (1.10–3.64). The estimates were consistent with small-to-moderate effect sizes using distributional analysis, and MCIDs were similar between COPD and non-COPD patients. The instruments were generally feasible and quick to use. ConclusionD12 and MDP are responsive to change and feasible for use for assessing multidimensional breathlessness in outpatients with cardiorespiratory disease. MCIDs were determined for use as endpoints in clinical trials.

Effect of Olfactory Stimulation by L-Menthol on Laboratory-Induced Dyspnea in COPD

Inhalation of L-menthol as a transient receptor potential melastatin 8 agonist induces a cooling sensation in the airway. This cooling sensation induced through olfactory stimulation by L-menthol (OSM) alleviates dyspnea in healthy humans. Therefore, we investigated effects of OSM on the neural respiratory drive (NRD) and multidimensional aspects of dyspnea induced by inspiratory resistive loaded breathing in COPD. In total, 28 patients with COPD and 14 control participants were included in this randomized, single-blinded, placebo-controlled, crossover study. OSM was administered using an L-menthol-scented patch, whereas placebo was administered using olfactory stimulation by strawberry-scented patch: placebo (OSP). Sham condition was measured by breathing through a face mask without a OSP. Dyspnea was evoked by breathing through the inspiratory resistance of 20 or 30cm H2O/L/s and measured using the Multidimensional Dyspnea Profile. NRD was estimated using the electromyogram activities of the parasternal intercostal muscles. Compared with sham and OSP, OSM did not alter the breathing pattern/timing and NRD during inspiratory resistive loading; however, it significantly alleviated the physical and mental breathing effort, air hunger, breathing discomfort, anxiety, and fear during inspiratory resistive loaded breathing in patients with COPD. However, although OSM reduced the air hunger, mental breathing effort, and unpleasantness, no significant improvement on affective dimension of dyspnea by OSM was observed in control participants. Our findings suggest that OSM activated the sense of inspiratory flow that achieved dyspnea relief in patients with COPD. UMIN Clinical Trials Registry (UMIN-CTR); No.: UMIN000033822; URL: https://www.umin.ac.jp/ctr/index.htm.

Multidimensional aspects of dyspnea in obese patients referred for cardiopulmonary exercise testing

We investigated the contributions of obesity on multidimensional aspects of dyspnea on exertion (DOE) in patients referred for clinical cardiopulmonary exercise testing (CPET). Ratings of perceived breathlessness (RPB, Borg scale 0–10) were collected in obese (BMI ≥ 30; n = 47) and nonobese (BMI ≤ 25; n = 27) patients during two (one lower: ∼30 W; and one higher: ∼50 W) 4−6 min constant load cycling bouts. Multidimensional dyspnea profiles (MDP) were collected in the final 26 obese and 14 nonobese patients of the sample. RPB was greater (p = 0.05) in obese (3.3 ± 2.2 vs 2.4 ± 1.4) at lower work rates, but similar at higher work rates (4.9 ± 2.2 vs 4.4 ± 1.8). MDP sensory score including unpleasantness was 4.3 ± 2.2 in obese vs 2.5 ± 1.9 in nonobese (p < 0.001). The affective score was 1.9 ± 2.2 vs 0.7 ± 0.7, respectively (p < 0.01). Breathing sensations including ‘air hunger’, ‘effort’, and ‘breathing at lot’ were greater (p < 0.05) in obese, making these patients more frustrated/angry (p < 0.05). Obesity should be considered as a potential independent influencing factor that provokes DOE and unpleasantness when assessing breathlessness during CPET.