Exercise-induced Dyspnea Research Articles

Exercise-Induced Bronchoconstriction and Vocal Cord Dysfunction

Patients are referred often because of self-reported symptoms of dyspnea and wheeze during exercise. The two common causes of exercise-induced dyspnea are exercise-induced bronchoconstriction (EIB) and vocal cord dysfunction (VCD). It can be extraordinarily difficult to differentiate between the two, especially because they may coexist in the same patient. EIB is caused by bronchial smooth muscle constriction in the lower airways due to the inhalation of dry air or allergens during exercise; it is associated with the release of bronchoconstricting mediators from airway cells. EIB can occur in patients with or without persistent asthma. In contrast, VCD is associated with the paradoxical adduction of the vocal cords, especially during inhalation, which may produce inspiratory stridor. VCD can be solitary or comorbid with asthma and/or EIB. EIB classically is most severe after the cessation of exercise, while VCD typically occurs during exercise and resolves quickly upon exercise cessation. However, history is not adequate to differentiate between EIB and VCD, and appropriate challenge tests and flexible laryngoscopy during exercise are often necessary for diagnosis. This article examines our current understanding of these entities and discusses the mechanism, prevalence, diagnosis, and treatment.

Influence of heredity on asthma continues to adulthood

Influence of heredity on asthma continues to adulthood

Exercise‐induced paradoxical vocal fold motion disorder

To review our experience with the diagnosis and treatment of exercise-induced paradoxical vocal fold motion disorder (EPVFMD). Single-institution retrospective review and cohort analysis. A single-institution retrospective review was performed identifying patients with paradoxical vocal fold motion disorder (PVFMD). Patients with isolated exercise-induced dyspnea were selected for further review. Flexible fiberoptic laryngoscopy (FFL) performed on these patients were reviewed with regard to presence of laryngeal pathology as well as the presence of PVFMD at rest and/or with exertion. The type of therapy was reviewed. Symptom outcomes were graded as complete resolution, improvement, or unchanged following therapy. There were 758 patients who were identified with PVFMD. A total of 104 patients demonstrated symptoms of PVFMD that were only exercise related (EPVFMD). There were 93/104 (89%) patients who underwent a pre- and post-trigger FFL. Of these, 48/93 (52%) patients had no evidence of PVFMD on initial FFL. After subjecting these patients to exertion, 83/93 (89%) had evidence of PVFMD on postexertion FFL, and 39/93 (42%) patients had evidence of PVFMD on both pre-exertion and postexertion FFL. There were 87/104 (84%) patients who had evidence of laryngeal edema, and 23/104 (23%) had one or more laryngeal lesion on examination. A total of 67 patients were enrolled in laryngeal control therapy and attended at least one session, with 48/67 (72%) demonstrating improvement or complete resolution of their symptoms. The diagnosis of EPVFMD is augmented with the addition of provocation testing. Findings of PVFMD can be identified at rest when asymptomatic. Laryngeal control therapy is an effective treatment for EPVFMD.

Underweight and overweight men have greater exercise-induced dyspnoea than normal weight men

Introduction. Persons with high or low body mass index (BMI), involved in clinical or mechanistic trials involving exercise testing, might estimate dyspnoea differently from persons with a normal BMI.Aims. Our objective was to investigate the relationship between BMI and dyspnoea during exercise in normal subjects with varying BMI.Material and methods. A total of 37 subjects undertook progressive exercise testing. Subjects were divided into three groups: underweight (UW), normal weight (NW), and overweight (OW). Dyspnoea was estimated using the visual analogue scale (VAS). Spirometry, maximum voluntary ventilation (MVV), and respiratory muscle strength (RMS) were measured.Results and discussion. The intercept of the VAS/ventilation relationship was significantly higher in NW subjects compared to UW (P = 0.029) and OW subjects (P = 0.040). Relative to the OW group, FVC (P = 0.020), FEV1 (P = 0.024), MVV (P = 0.019), and RMS (P = 0.003) were significantly decreased in the UW group. The greater levels of dyspnoea in UW subjects could possibly be due to decreased RMS. Healthy persons should aim to achieve an optimum BMI range to have the lowest exercise-induced dyspnoea.

Current best practice in pulmonary rehabilitation for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic condition that negatively affects several patient-centered outcomes. Among these, exercise capacity, dyspnea, and quality of life are the most relevant. In this article, factors contributing to exercise limitation, increase in exercise-induced dyspnea, quality of life deterioration, and other pathophysiological aspects in patients with COPD are analyzed in detail. Pulmonary rehabilitation (PR) is an evidence-based, multidisciplinary, and comprehensive intervention for patients with chronic respiratory diseases who are symptomatic and often have decreased daily life activities. PR has been clearly shown to induce favorable and long-lasting effects on all patient-centered outcomes. In addition, PR appears to have positive (even if not conclusively demonstrated) effects on other important outcomes in patients with COPD: number and severity of exacerbations, healthcare resource utilization, and survival. The organization of PR treatment, its components, outcome assessment, and future directions are discussed in light of the most robust scientific evidence.

Proposing a standardized method for evaluating patient report of the intensity of dyspnea during exercise testing in COPD

BackgroundMeasuring dyspnea intensity associated with exercise provides insights into dyspnea-limited exercise capacity, and has been used to evaluate treatment outcomes for chronic obstructive pulmonary disease (COPD). Three patient-reported outcome scales commonly cited for rating dyspnea during exercise are the modified Borg scale (MBS), numerical rating scale for dyspnea (NRS-D), and visual analogue scale for dyspnea (VAS-D). Various versions of each scale were found. Our objective was to evaluate the content validity of scales commonly used in COPD studies, to explore their ability to capture patients’ experiences of dyspnea during exercise, and to evaluate a standardized version of the MBS.MethodsA two-stage procedure was used, with each stage involving one-on-one interviews with COPD patients who had recently completed a clinic-based exercise event on a treadmill or cycle ergometer. An open-ended elicitation interview technique was used to understand patients’ experiences of exercise-induced dyspnea, followed by patients completing the three scales. The cognitive interviewing component of the study involved specific questions to evaluate the patients’ perspectives of the content and format of the scales. Results from Stage 1 were used to develop a standardized version of the MBS, which was then subjected to further content validity assessment during Stage 2.ResultsThirteen patients participated in the two-stage process (n = 6; n = 7). Mean forced expiratory volume in 1 second (FEV1) percent predicted was 40%, mean age 57 years, and 54% were male. Participants used a variety of terms to describe the intensity and variability of exercise-induced dyspnea. Subjects understood the instructions and format of the standardized MBS, and were able to easily select a response to report the level of dyspnea associated with their recent standardized exercise.ConclusionThis study provides initial evidence in support of using a standardized version of the MBS version for quantifying dyspnea intensity associated with exercise in patients with COPD.

A cardiac hydatid cyst underlying pulmonary embolism: a case report

Hydatid cysts located in the interatrial septum are especially rare but when they occur, they might cause intracavity rupture. We report on a patient with acute pulmonary embolism caused by an isolated, ruptured hydatid cyst on the right side of the interatrial septum. A 16-year-old-boy with an uneventful history was hospitalized for exercise-induced dyspnea and blood expectorations. Multiple and bilateral opacities were visualized on standard chest x-ray. Signs of right-sided hypertrophy were seen on ECG. Imaging findings led to the diagnosis of pulmonary embolism complicating cardiac hydatid cysts. An operation was performed through median sternotomy to remove the cardiac cyst. The pleural cavity was entered through the fifth intercostal space to withdraw lung hydatid cysts. Operative recovery was uneventful and the patient resumed his normal activities 19 months later. Prompt diagnosis and an appropriate surgical treatment prevented a potentially fatal outcome.

Relationship between anxiety and dyspnea on exertion in patients with chronic obstructive pulmonary disease

Dyspnea limits exercise in patients with chronic obstructive pulmonary disease (COPD) and is known to induce anxiety. Little is known whether anxiety contributes to exercise-induced dyspnea, which in turn might influence the outcome of diagnostic tests. The aim of the present study was to examine the relationship between general anxiety and dyspnea on exertion in patients with COPD. Ninety patients with stable COPD participated; 44 men, mean age 61 (standard deviation (SD) 10.4), and mean forced expiratory volume in 1 second (%pred.) 40.5 (SD 16.9). All participants performed pulmonary function tests and an incremental cycle ergometry. The Modified Borg Scale was used to measure the level of dyspnea on exertion. Anxiety symptoms were assessed with the Hospital Anxiety and Depression Scale. Data were analyzed using Spearman's correlations and multivariate regression. Dyspnea on exertion was correlated with general anxiety (r=.31), age (r=–.30), and exercise capacity (r=.27). Regression analysis showed that general anxiety was associated with dyspnea on exertion, adjusted for sex, age, baseline dyspnea, and exercise capacity. Consequently, it is reasoned that results of exercise training and activities in daily living may be influenced negatively by anxiety-worsened dyspnea. Attention should be given to anxiety management in patients with COPD to optimize exercise training.

Sex differences in exertional dyspnea in patients with mild COPD: Physiological mechanisms

The purpose of this study was to evaluate the physiological basis for sex-differences in exercise-induced dyspnea in patients with mild COPD. We compared operating lung volumes, breathing pattern and dyspnea during incremental cycling in 32 men (FEV(1)=86±10% predicted) and women (FEV(1)=86±12% predicted) with mild COPD and 32 age-matched controls. There were no sex differences in dyspnea in the control group at any work-rate or ventilation (V(E)). Women with COPD had significantly greater dyspnea than men at 60 and 80 W. At 80 W, dyspnea ratings were 5.7±2.3 and 3.3±2.5 Borg units (P<0.05) and the V(E) to maximal ventilatory capacity ratio was 72% and 55% in women and men, respectively (P<0.05). Comparable increases in dynamic hyperinflation were seen in both male and female COPD groups at symptom limitation but women reached tidal volume constraints at a lower work rate and V(E) than men. Superimposing mild COPD on the normal aging effects had greater sensory consequences in women because of their naturally reduced ventilatory reserve.

Predictive factors for airway hyperresponsiveness in children with respiratory symptoms

Asthma diagnosis is a challenging condition, particularly in patients without obstructive pattern and reversibility on spirometry. Determination of airway hyperresponsiveness (AHR) may be helpful, but the procedure is time-consuming and not always practical. To determine the potential factors that may predict the presence of AHR in children with asthmalike symptoms but without obstructive pattern and reversibility on spirometry. All patients with asthmalike symptoms but without obstructive pattern and reversibility on spirometry were analyzed retrospectively between January 9, 2007, and December 30, 2009. The features of clinical history and laboratory results were analyzed with univariate and multivariate regression analysis. A total of 111 children between 6 and 18 years of age, with a median age of 10.2 years, were analyzed, and AHR was detected in 67 patients (60.3%). Multivariate logistic regression analysis revealed coexistence of nocturnal cough and exercise-induced cough (odds ratio [OR], 22.1; 95% confidence interval [CI], 3.1-159.2; P = .004), eosinophilia (OR, 18.7; 95% CI, 1.9-178.7; P = .01), and borderline bronchodilator response in forced expiratory volume in 1 second (between 7% and 11%) (OR, 10.1; 95% CI, 2.1-49.1; P = .004) as significant risk factors for the presence of AHR, whereas exercise-induced dyspnea was found to be related to the absence of AHR (OR, 0.2; 95% CI, 0.1-0.8; P = .02). In children with asthmalike symptoms but with normal spirometry, certain features of clinical history and laboratory results can strongly predict the presence of AHR and may help less frequent use of challenge tests.

Dyspnoea and oxygen therapy in chronic obstructive pulmonary disease

Background: Chronic obstructive pulmonary disease (COPD) is common, incurable and characterized by disabling dyspnoea, functional decline and reduced quality of life. The mechanisms underlying dyspnoea in COPD are complex and few strategies have been found to alleviate it. Oxygen therapy has been shown to improve survival for patients with COPD and severe resting hypoxaemia when used for ⩾15 hours per day, long-term.Objectives: This paper reviews factors contributing to dyspnoea in COPD and the role of oxygen therapy in its management.Major findings: The causes of dyspnoea in COPD are not fully understood. Dyspnoea involves an interaction between altered pulmonary mechanics and abnormalities of gas exchange and skeletal muscle. A disparity arises between effort expended to meet ventilatory demand and feedback from chemo- and other receptors, influenced by psychosocial and behavioural factors. Oxygen therapy reduces exertional dyspnoea acutely in COPD with and without hypoxaemia. The use of supplemental oxygen during exercise training may allow higher training intensities to be achieved and thus may be beneficial, but the long-term effects are unknown. There is no evidence that continuous long-term oxygen therapy improves dyspnoea in COPD with severe hypoxaemia. For patients without severe resting hypoxaemia, ambulatory oxygen, provided for use during exertion, confers no benefits upon dyspnoea. Further, there is no evidence to support the use of supplementary oxygen for alleviation of dyspnoea at rest, before or after exertion.Conclusions: In patients with COPD, oxygen reduces exercise-induced dyspnoea acutely, but the relationship between oxygen and dyspnoea in other situations is less clear. A low oxygen level does not always lead to dyspnoea and similarly supplemental oxygen does not always reduce dyspnoea.

PULMONARY REHABILITATION AND NON-INVASIVE VENTILATION IN COPD

A multidisciplinary pulmonary rehabilitation program has become an important part of the treatment of chronic obstructive pulmonary disease. It can improve both exercise tolerance and health related quality of life in these patients (1). Exercise training has to be included for the program to be successful (2,3).The intensity of the training is of great importance: there is more physiological benefit in high-intensity training, compared to moderate-intensity training (4). High-intensity training results in reduced levels of blood lactate and pulmonary ventilation at a given heavy work rate (5). High-intensity training is limited in COPD patients because of exercise-induced dyspnoea. Flow limitation, as a consequence of increased ventilatory demands of exercise, causes a breathing pattern with greater demands on their inspiratory muscles: this results in a pattern of low tidal volume and high-frequency breathing. Increased inspiratory muscle work causes dyspnoea and limitation in exercise intensity (6).Artificial ventilatory assistance could improve exercise tolerance and hence help severe COPD patients to achieve a higher level of training (7). It could help to unload and assist the overburdened ventilatory muscles and give a possibility for higher levels of exercise intensity.In this review article we will discuss the effectiveness and feasibility of training with ventilatory aids.

Aorticopulmonary septal defect in a dog: case report

A 10-month-old intact female mixed breed dog was referred for evaluation of exercise-induced dyspnea and a low grade II/VI systolic murmur was detected. The communication between ascending aortic and pulmonary trunk was observed by detecting a continuous flow just above the semilunar valves on echoDopplercardiography and attested by surgery. After the surgical procedure, the dog was presented in good clinical conditions without exercise-induced dyspnea, reflecting the importance of an early and accurate diagnostic for the therapeutic success. This is the first Brazilian report of this rare congenital disease and the unique well succeed surgery in the veterinary literature.

Exercise-Induced Dyspnea: Vocal Cord Dysfunction and Asthma

Exercise-Induced Dyspnea: Vocal Cord Dysfunction and Asthma

Impact of a Rehabilitation Program on Dyspnea Intensity and Quality in Patients with Chronic Obstructive Pulmonary Disease

Background: It has yet to be determined whether the language of dyspnea responds to pulmonary rehabilitation programs (PRP). Objective: We tested the hypothesis that PRP affect both the intensity and quality of exercise-induced dyspnea in patients with chronic obstructive pulmonary disease (COPD). Methods: We studied 49 patients equipped with a portable telemetric spiroergometry device during the 6-min walking test before and 4 weeks after PRP. In a first screening visit, appropriate verbal descriptors of dyspnea were chosen that patients were familiar with during daily living activities. Tidal volume, respiratory frequency, inspiratory capacity, inspiratory reserve volume (IRV) and dyspnea intensity were evaluated by a modified Borg scale every minute during the test. Results: Qualitative descriptors of dyspnea were defined by three different sets of cluster descriptors (a–c) at the end of the exercise test, before and after PRP: a – work/effort (W/E); b – inspiratory difficulty (ID) and chest tightness (CT), and c – W/E, ID and/or CT. The three language subgroups exhibited similar lung function at baseline, and similar rating of dyspnea and ventilatory changes during exercise. The rehabilitation program shifted the Borg-IRV relationship (less Borg at any given IRV) towards the right without modifying the set of descriptors in most patients. Conclusions: Rehabilitation programs allowed patients to tolerate a greater amount of restrictive dynamic ventilatory defect by modifying the intensity, but not necessarily the quality of dyspnea.

Diagnostik und Therapie parapneumonischer Pleuraergüsse – Fall 10/2009

We report on a 47-year-old male patient who was admitted for exercise-induced dyspnea and easy fatigability. Physical examination revealed reduced breath and percussion sounds of the left basal lung. Laboratory investigations revealed leucocytosis and elevated C-reactive protein levels. Chest X-ray showed an area of increased opacity of the left lower hemithorax. Computed tomography (CT) confirmed an encapsulated, septated pleural effusion. The aspirate was purulent with abundant neutrophil granulocytes and a pH value of 7.1. A diagnosis of left-sided pleural empyema was made, most probably following pneumonia. Antibiotic treatment with amoxicillin and clavulan acid was initiated and after insertion of a chest drain pleural irrigation with daily 200,000 I.U. streptokinase was performed for five days. The drainage was removed after ten days and after four months CT showed a complete remission of the lef-sided pleural empyema. Parapneumonic effusions are frequent with broad clinical range from trivial to life-threatening. Therapy decision is based on the characteristics of the effusion and the patient's clinical status and should be made within an interdisciplinary cooperation between internists and (thoracic) surgeons.

Proportional Assist Ventilation Improves Exercise Capacity in Patients with Obesity

Background: Exercise capacity is reduced in obese patients due to disadvantageous respiratory mechanics that lead to dyspnea. Proportional assist ventilation (PAV) has the potential to unload resistive and elastic burdens of the ventilatory system. Objectives: The present study aimed to test if PAV can increase endurance and reduce exercise-related dyspnea in obese patients. Methods: Two symptom-limited exercise tests were performed at 75% of V·O_2max: (1) without PAV and (2) with PAV. Exercise endurance, blood gases, dyspnea and limb discomfort (Borg scale) were assessed. Responders to PAV were defined as those increasing their exercise duration by more than 20%. Results: Eighteen male obese patients (body mass index 35 ± 5 kg/m²) were investigated. Overall, PAV increased exercise duration by 13% (p = 0.037) and improved exercise-induced dyspnea (p = 0.004). In responders (n = 10), PAV increased the exercise duration by 31% from 721 ± 300 to 1,041 ± 454 s (p < 0.001) and reduced dyspnea (p = 0.004) as well as limb discomfort (p = 0.016). Following stepwise multiple linear regression analysis, prolonged exercise time with PAV can only be predicted from total lung capacity (p = 0.02), considering total lung capacity, V·O_2max and body mass index. Conclusions: PAV applied during exercise led to an overall prolongation in exercise endurance and a reduction in dyspnea in obese patients. There was a broad spectrum of response to PAV, with more than 50% of patients increasing their exercise endurance by a mean of 31%. Therefore, PAV might serve as a novel treatment option to enhance exercise capacity in a subgroup of obese patients in rehabilitation programs.

Quality of recalled dyspnoea is different from exerciseinduced dyspnoea: an experimental study

Are volunteered and endorsed descriptors of recalled breathlessness consistent with descriptors of exercise-induced breathlessness? Are volunteered and endorsed descriptors of exercise-induced breathlessness consistent? Within-participant, repeated measures, experimental study. 57 people with symptomatic chronic respiratory disease aged 71 years. There were three conditions. The first was recalled breathlessness. Two conditions of exercise-induced breathlessness were created by getting the participants to undertake the 6-min Walk Test twice (breathlessness 1 and 2). Descriptors of breathlessness were volunteered (where participants' used their own words) or endorsed (from a pre-existing list of 15 breathlessness statements). Emotive descriptors made up 65% of recalled descriptors compared with 11% of exercise-induced descriptors, whereas physical descriptors made up 35% of recalled descriptors compared with 89% of exercise-induced descriptors. Of the 237 potential language pairs volunteered to describe recalled and exercise-induced breathlessness 1, only 27 (11%) were identical whereas of the 171 potential language pairs endorsed as describing recalled and exercise-induced breathlessness 1, 66 (39%) were identical. Of the 175 potential language pairs of descriptors volunteered to describe exercise-induced breathlessness 1 and 2, 72 (41%) were identical whereas of the 153 potential language pairs endorsed as describing exercise-induced breathlessness 1 and 2, 71 (46%) were identical. The language used to describe exercise-induced breathlessness immediately after two walking challenges was similar. However, descriptions of recalled breathlessness did not consistently match descriptions of exercise-induced breathlessness, which may reflect the different contexts under which breathlessness was recalled and induced.

Sinusitis and chronic progressive exercise-induced cough and dyspnea

We present the case of a 47-year-old man with exercise-induced dyspnea, cough, chest tightness, and recalcitrant chronic rhinosinusitis. Evaluation revealed IgE sensitization to grass, tree, and weed pollen, no evidence of obstruction on spirometry, and a negative methacholine challenge. Diagnostic considerations included allergic and nonallergic rhinitis, asthma, aspirin-exacerbated respiratory disease, vocal cord dysfunction, extra-esophageal manifestations of acid reflux, and vasculitits. Further evaluation with sinus imaging, laryngoscopy, ambulatory pharyngeal pH testing, upper endoscopy, and bronchoscopy led to a diagnosis. Key issues surrounding the diagnostic and therapeutic approaches to this patient's condition are reviewed.

β-Adrenergic Blockade and Metabo-Chemoreflex Contributions to ExerciseCapacity

Exercise-induced dyspnea in patients with cardiopulmonary diseases may be related to sympathetic nervous system activation, with increased metabo- and/or chemosensitivities. Whether this mechanism plays a role in exercising normal subjects remains unclear. Muscle sympathetic nerve activity (MSNA), HR, ventilation (V(E)), O2 saturation (SpO2), and end-tidal PCO2 (PetCO2) were measured in 14 healthy young adults after 1 wk of beta1-receptor blockade with bisoprolol 5 mg x d(-1) versus placebo after a double-blind, placebo-controlled, randomized crossover design. The MSNA and the ventilatory responses to hyperoxic hypercapnia (7% CO2 in O2), DeltaV(E)/DeltaPetCO2, and isocapnic hypoxia (10% O2 in N2), DeltaV(E)/DeltaSpO2, and to an isometric muscle contraction followed by a local circulatory arrest (metaboreflex) were determined at rest followed by an incremental cardiopulmonary exercise test. Bisoprolol did not change the V(E) and MSNA responses to hypercapnia, hyperoxia, or isometric muscle contraction or ischemia. Bisoprolol decreased maximum O2 uptake (P < 0.05), workload (P < 0.05), and HR (P < 0.0001) and both V(E)/VO2 and V(E)/VCO2 slopes (P < 0.05). These results suggest that decreased aerobic exercise capacity after intake of beta-blockers is accompanied by decreased ventilation at any metabolic rate. However, this occurs without detectable change in the sympathetic nervous system tone or in metabo- or chemosensitivity and is therefore probably of hemodynamic origin.