Mechanisms and consequences of excess exercise ventilation in fibrosing interstitial lung disease.

The causes and consequences of excess exercise ventilation (EEV) in patients with fibrosing interstitial lung disease (f-ILD) were explored. Twenty-eight adults with f-ILD and 13 controls performed an incremental cardiopulmonary exercise test. EEV was defined as ventilation-carbon dioxide output (⩒E-⩒CO2) slope ≥36 L/L. Patients showed lower pulmonary function and exercise capacity compared to controls. Lower DLCO was related to higher ⩒E-⩒CO2 slope in patients (P<0.05). 13/28 patients (46.4%) showed EEV, reporting higher dyspnea scores (P=0.033). Patients with EEV showed a higher dead space (VD)/tidal volume (VT) ratio while O2 saturation dropped to a greater extent during exercise compared to those without EEV. Higher breathing frequency and VT/inspiratory capacity ratio were observed during exercise in the former group (P<0.05). An exaggerated ventilatory response to exercise in patients with f-ILD is associated with a blunted decrease in the wasted ventilation in the physiological dead space and greater hypoxemia, prompting higher inspiratory constraints and breathlessness.

Dynamic Ventilatory Reserve During Incremental Exercise: Reference Values and Clinical Validation in Chronic Obstructive Pulmonary Disease.

Rationale: Ventilatory demand-capacity imbalance, as inferred based on a low ventilatory reserve, is currently assessed only at peak cardiopulmonary exercise testing (CPET). Peak ventilatory reserve, however, is poorly sensitive to the submaximal, dynamic mechanical ventilatory abnormalities that are key to dyspnea genesis and exercise intolerance. Objectives: After establishing sex- and age-corrected norms for dynamic ventilatory reserve at progressively higher work rates, we compared peak and dynamic ventilatory reserve for their ability to expose increased exertional dyspnea and poor exercise tolerance in mild to very severe chronic obstructive pulmonary disease (COPD). Methods: We analyzed resting functional and incremental CPET data from 275 controls (130 men, aged 19-85 yr) and 359 Global Initiative for Chronic Obstructive Lung Disease patients with stage 1-4 obstruction (203 men) who were prospectively recruited for previous ethically approved studies in three research centers. In addition to peak and dynamic ventilatory reserve (1 - [ventilation / estimated maximal voluntary ventilation] × 100), operating lung volumes and dyspnea scores (0-10 on the Borg scale) were obtained. Results: Dynamic ventilatory reserve was asymmetrically distributed in controls; thus, we calculated its centile distribution at every 20 W. The lower limit of normal (lower than the fifth centile) was consistently lower in women and older subjects. Peak and dynamic ventilatory reserve disagreed significantly in indicating an abnormally low test result in patients: whereas approximately 50% of those with a normal peak ventilatory reserve showed a reduced dynamic ventilatory reserve, the opposite was found in approximately 15% (P < 0.001). Irrespective of peak ventilatory reserve and COPD severity, patients who had a dynamic ventilatory reserve below the lower limit of normal at an isowork rate of 40 W had greater ventilatory requirements, prompting earlier attainment of critically low inspiratory reserve. Consequently, they reported higher dyspnea scores, showing poorer exercise tolerance compared with those with preserved dynamic ventilatory reserve. Conversely, patients with preserved dynamic ventilatory reserve but reduced peak ventilatory reserve reported the lowest dyspnea scores, showing the best exercise tolerance. Conclusions: Reduced submaximal dynamic ventilatory reserve, even in the setting of preserved peak ventilatory reserve, is a powerful predictor of exertional dyspnea and exercise intolerance in COPD. This new parameter of ventilatory demand-capacity mismatch may enhance the yield of clinical CPET in the investigation of activity-related breathlessness in individual patients with COPD and other prevalent cardiopulmonary diseases.

Cardiopulmonary exercise testing to indicate increased ventilatory variability in subjects with dysfunctional breathing.

BACKGROUND: Dysfunctional breathing (DB) is a common, but largely underappreciated, cause of chronic dyspnoea. Under visual inspection, most subjects with DB present with larger sequential changes in ventilation (V̇E) and breathing pattern (tidal volume (VT) and breathing frequency (f)) before and/or during incremental cardiopulmonary exercise testing (CPET). Currently, however, there are no objective criteria to indicate increased ventilatory variability in these subjects. METHODS: Twenty chronically dyspnoeic subjects with DB and 10 age- and sex-matched controls performed CPET on a cycle ergometer. Cut-offs to indicate increased V̇E, VT, f, and f/VT ratio variability (Δ = highest-lowest 20 s arithmetic mean) over the last resting minute (rest ), the 2sd min of unloaded exercise (unload ), and the 3rd min of loaded exercise (load ) were established by ROC curve analyses. RESULTS: Subjects with DB presented with increased V̇E, higher ventilatory variability, higher dyspnoea burden, and lower exercise capacity compared to controls (p < 0.05). ΔV̇Eload (>4.1 L/min), Δfrest (>5 breaths/min; bpm), Δfunload (>4 bpm), Δfload (>5 bpm), Δf/VTrest (>4.9 bpm/L), and Δf/VTload (>1.3 bpm/L) differentiated DB from a normal pattern (areas under the curve ranging from 0.729 to 0.845). High Δf, in particular, was associated with DB across all CPET phases. CONCLUSIONS: This study provides objective criteria to indicate increased ventilatory variability during incremental CPET in dyspnoeic subjects with DB. Large variability in breathing frequency seems particularly useful in this context, a finding that should be prospectively confirmed in larger studies.

Responses to progressive exercise in subjects with chronic dyspnea and inspiratory muscle weakness.

INTRODUCTION: Inspiratory muscle weakness (IMW) is a potential cause of exertional dyspnea frequently under-appreciated in clinical practice. Cardiopulmonary exercise testing (CPET) is usually requested as part of the work-up for unexplained breathlessness, but the specific pattern of exercise responses ascribed to IMW is insufficiently characterized. OBJECTIVES: To identify the physiological and sensorial responses to progressive exercise in dyspneic patients with IMW without concomitant cardiorespiratory or neuromuscular diseases. METHODS: Twenty-three subjects (18 females, 55.2 ± 16.9 years) complaining of chronic daily life dyspnea (mMRC = 3 [2-3]) plus maximal inspiratory pressure < the lower limit of normal and 12 matched controls performed incremental cycling CPET. FEV1/FVC<0.7, significant abnormalities in chest CT or echocardiography, and/or an established diagnosis of neuromuscular disease were among the exclusion criteria. RESULTS AND CONCLUSION: Patients presented with reduced aerobic capacity (peak V̇O2: 79 ± 26 vs 116 ± 21 %predicted), a tachypneic breathing pattern (peak breathing frequency/tidal volume = 38.4 ± 22.7 vs 21.7 ± 14.2 breaths/min/L) and exercise-induced inspiratory capacity reduction (-0.17 ± 0.33 vs 0.10 ± 0.30 L) (all P < .05) compared to controls. In addition, higher ventilatory response (ΔV̇E/ΔV̇CO2 = 34.1 ± 6.7 vs 27.0 ± 2.3 L/L) and symptomatic burden (dyspnea and leg discomfort) to the imposed workload were observed in patients. Of note, pulse oximetry was similar between groups. Reduced aerobic capacity in the context of a tachypneic breathing pattern, inspiratory capacity reduction and preserved oxygen exchange during progressive exercise should raise the suspicion of inspiratory muscle weakness in subjects with otherwise unexplained breathlessness.

Tidal Flow-Volume Loop Enveloping at Rest in Advanced COPD.

BACKGROUND: Expiratory flow limitation (EFL) is a key physiological abnormality in COPD. Comparing tidal-to-maximum flow-volume (F-V) loops is a simple and widely available method to assess EFL in patients with COPD. We aimed to investigate whether subjects with COPD showing significant resting tidal F-V enveloping (ie, > 50% tidal volume) would present with higher exertional operating lung volumes, which would lead to greater burden of dyspnea and poorer exercise tolerance compared to their counterparts. METHODS: 37 subjects with COPD (21 males; 63.1 ± 9.2 years old; FEV1 = 37 ± 12% predicted) and 9 paired controls (3 males; 55.9 ± 11.7 y old) performed an incremental cardiopulmonary exercise testing on a cycle ergometer. Dyspnea perception, inspiratory capacity maneuvers after 3-4 sequential tidal F-V loops, and esophageal and gastric pressures were measured during exercise. RESULTS: Most subjects (31 of 37, 84%) presented with significant tidal F-V enveloping. Critical inspiratory constraints and upward dyspnea inflection points (as a function of both work rate and ventilation) were reached earlier in these subjects, thereby leading to poorer exercise tolerance compared to their counterparts (P = .01). Abdominal muscle recruitment (ie, increase in gastric pressure ≥ 15%) during tidal expiration was significantly higher in the EFL+ group. However, this did not bear an influence on the operating lung volumes, inspiratory constraints, dyspnea, cardiocirculatory responses, or exercise tolerance (P > .05). CONCLUSIONS: Tidal F-V loop enveloping at rest should be valued as it is related to relevant clinical outcomes, such as dyspnea burden and exercise tolerance in subjects with COPD.

Sensory consequences of critical inspiratory constraints during exercise in pulmonary arterial hypertension.

We aimed to assess detailed ventilatory and sensory responses to exercise contrasting subjects with and without PAH. 20 non-smoking patients with PAH (37.5 ± 12.1 ys; FEV1/FVC = 0.77 ± 0.04; mPAP by heart catheterization = 50.6 ± 18.1 mmHg) and 10 matched controls performed cycling cardiopulmonary exercise test with serial assessments of dyspnea, airway occlusion pressure during the first 0.1 s (P0.1) of tidal volume and inspiratory capacity (IC). Patients showed lower spirometric variables compared to controls. Dyspnea and ventilation (VE) were significantly higher in patients for a given work rate. Dyspnea persisted more intense in patients even when expressed as a function of VE. Lower IC at rest (in non-hyperinflators; n = 10) or exercise-induced reduction in IC (in hyperinflators) predisposed patients to achieve earlier and at lower workloads a critical inspiratory reserve volume (IRV). At this point, there was a sudden rise in P0.1 and dyspnea perception. Attainment of a critical IRV at premature workloads leads to neuromechanical dissociation with an abrupt increment in exertional dyspnea.

Low exertional inspiratory capacity is not related to dynamic inspiratory muscle weakness in heart failure.

Reduction in inspiratory capacity (IC) during exercise has been reported in chronic heart failure (CHF). Since inspiratory muscle dysfunction may be present to a variable degree, the assumption that IC reduction during exercise represents an increase in end-expiratory lung volume must be made with caution. This interpretation is flawed if patients develop dynamic inspiratory muscle strength reduction, i.e., progressively lower esophageal (Pes) pressures as the IC maneuvers are repeated. Sixteen CHF patients and 9 age-matched controls performed an incremental exercise test with serial IC and respiratory pressure measurements. Regardless whether IC decreased or not with exercise (N = 4 and N = 12, respectively), Pes,IC remained stable. This was confirmed by similar Pes,sniff immediately upon exercise cessation (p > .05). No association was found between changes in IC and related Pes from rest to peak exercise. Owing to the lack of dynamic inspiratory muscle weakness, non-invasive indexes of lung mechanics can be reliably obtained from exercise IC in CHF.

A Simplified Approach to Select Exercise Endurance Intensity for Interventional Studies in COPD.

Time to exercise limitation (Tlim) in response to constant work rate (CWR) is sensitive to interventions in chronic obstructive pulmonary disease (COPD). This is particularly true when the pre-intervention test lasts between 3 and 8 min (Tlim3'-8'). There is, however, no simple method to select a work rate which is consistently associated with Tlim3'-8' across the spectrum of COPD severity. We assessed 59 GOLD stages II-IV patients who initially cycled to Tlim at 75% peak. In case of short (<3 min, low-endurance) or long (>8 min, high-endurance) tests, patients exercised after 60 min at 50% or 90%, respectively (CWR50%⇐75%⇒90%). Critical mechanical constraints and limiting dyspnea at 75% were reached within the desired timeframe in 27 "mid-endurance" patients (46%). Increasing work rate intensity to 90% hastened the mechanical-ventilatory responses leading to Tlim3'-8' in 23/26 (88%) "high-endurance" patients; conversely, decreasing exercise intensity to 50% slowed those responses leading to Tlim3'-8' in 5/6 (83%) "high-endurance" patients. Repeating the tests at higher (60%) or lower (80%) intensities fail to consistently produce Tlim3'-8' in "low-" and "high-endurance", respectively (p > 0.05). Compared to a fixed work rate at 75%, CWR50%⇐75%⇒90% significantly decreased Tlim's coefficient of variation; consequently, the required N to detect 100 s or 33% improvement in Tlim decreased from 82 to 26 and 41 to 14, respectively. This simplified approach to individualized work rate adjustment (CWR50%⇐75%⇒90%) might allow greater sensitivity in evaluating interventional efficacy in improving respiratory mechanics and exercise tolerance while simultaneously reducing sample size requirements in patients with COPD.

Characteristics associated with mortality in patients with chronic obstructive pulmonary disease (COPD)-heart failure coexistence.

AimTo investigate if cardiac/pulmonary functional tests and variables obtained from clinical practice (body mass index, dyspnea, functional class, clinical judgment of disability to perform an exercise test and previous hospitalization rate) are related to mortality in patients with overlap chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF). BACKGROUND: Although the coexistence of COPD and CHF has been growingly reported, description of survival predictors considering the presence of both conditions is still scarce. METHODS: Using a cohort design, outpatients with the previous diagnosis of COPD and/or CHF that performed both spirometry and echocardiography in the same year were followed-up during a mean of 20.9±8.5 months.FindingsOf the 550 patients initially evaluated, 301 had both spirometry and echocardiography: 160 (53%) with COPD on isolation; 100 (33%) with CHF on isolation; and 41 (14%) with overlap. All groups presented similar mortality: COPD 17/160 (11%); CHF 12/100 (12%); and overlap 7/41 (17%) (P=0.73). In the overlap group (n=41), inability to exercise and hospitalization rate were the unique parameters associated with higher mortality (seven events) in univariate analyses. In conclusion, inability to exercise and hospitalization rate emerged as the unique parameters associated with mortality in our sample.

Effectiveness assessment of a guideline based protocol for ventilatory support management of COPD exacerbations in an emergency department.

OBJECTIVES: To investigate clinical outcomes according to ventilatory support indication in subjects with chronic obstructive pulmonary disease exacerbation in a "real-life" Emergency Department and to analyze potential predictors of successful noninvasive positive pressure ventilation. METHODS: Retrospective cohort performed over an 18-month period, comparing the following patient groups with chronic obstructive pulmonary disease exacerbation: Group A composed of patients initially selected to receive noninvasive positive pressure ventilation without the subsequent need for invasive mechanical ventilation (successful-noninvasive positive pressure ventilation); Group B composed of patients transitioning from noninvasive positive pressure ventilation to invasive mechanical ventilation (failed-noninvasive positive pressure ventilation); and Group C composed of patients who presented with immediate need for invasive mechanical ventilation (without prior noninvasive positive pressure ventilation). RESULTS: 117 consecutive chronic obstructive pulmonary disease exacerbation admissions (Group A=96; Group B=13; Group C=8) of candidates for ventilatory support were reviewed. No differences in baseline disease severity and physiological parameters were found between the groups at Emergency Department admission. Nevertheless, Group B had higher intensive care unit admission, length of hospital stay, length of intensive care unit stay, and higher in-hospital mortality compared to Group A. Group C also had worse outcomes when compared to Group A. The only independent variable associated with the successful use of noninvasive positive pressure ventilation were improvement in arterial carbon dioxide pressure after 1h of noninvasive positive pressure ventilation use and its tolerance. CONCLUSION: Our data confirmed in a "real life" Emergency Department cohort that successful management of chronic obstructive pulmonary disease exacerbation with noninvasive positive pressure ventilation showed lower in-hospital mortality and Intensive Care Unit stay when compared to patients transitioning from noninvasive positive pressure ventilation to invasive mechanical ventilation or patients who presented an immediate need for invasive mechanical ventilation. noninvasive positive pressure ventilation tolerance and higher arterial carbon dioxide pressure reduction after 1-h of noninvasive positive pressure ventilation were predictors of successful treatment. These results should be confirmed in a prospective randomized controlled trial.

Efeito da terapia por radiofrequência monopolar sobre a dor e capacidade funcional de mulheres com fibromialgia / Effect of monopolar radiofrequency on pain and functional capacity of women with fibromyalgia

Introdução: O tratamento através da eletroterapia está cada vezmais utilizado como um recurso terapêutico para redução de quadrosálgicos na Fisioterapia. No entanto, são escassos os estudos analisandoos efeitos da radiofrequência de modo contínuo não ablativo empacientes com fibromialgia. Objetivo: Este estudo objetivou avaliaros efeitos da terapia por radiofrequência monopolar (RFM) na dore no cotidiano de mulheres com fibromialgia. Método: Participaramdeste estudo mulheres com diagnóstico clínico de fibromialgia, queforam submetidas a 8 sessões de RFM. Os atendimentos ocorreram 2vezes por semana. Os resultados do tratamento foram avaliados pelaEscala Visual Analógica (EVA) e pelo Fibromyalgia Impact Questionary(FIQ). Para comparar os resultados pré e pós tratamentoutilizou-se o teste T Pareado do software Statistica 7.1. Resultados:Participaram deste estudo 9 mulheres com idade média de 53,25 (±8,48) anos. Verificou-se alívio da dor imediatamente após as sessõesde RFM (p < 0,01). Houve repercussão positiva do tratamento nocotidiano dessas pacientes, visto que ocorreu significativa reduçãodo escore do FIQ após as 8 sessões (p = 0,03). Conclusão: A partirdos resultados deste estudo, sugere-se que a terapia por RFM podeser mais um aliado do fisioterapeuta para o tratamento de pacientescom fibromialgia. Contudo, os resultados desta pesquisa devem seranalisados com cautela, pois não houve um grupo controle paragarantir que os resultados positivos deveram-se unicamente ao tratamentoe não a outros fatores desconsiderados pelos pesquisadores.

Introduction: The treatment by electrotherapy is increasinglyused as a therapeutic resource for reducing painful picture in PhysicalTherapy. However, there are few studies analyzing the effectsof continuous and non-ablative radiofrequency in patients with fibromyalgia.Objective: This study evaluated the effects of monopolarradiofrequency on pain and daily life of women with fibromyalgia.Methods: The study included women diagnosed with fibromyalgia,who underwent eight sessions of RFM monopolar radiofrequency.The sessions occurred twice a week. The treatment results wereevaluated by Visual Analogue Scale (VAS) and the FibromyalgiaImpact Questionnaire (FIQ). To compare the results before and aftertreatment, we used paired t-test from software Statistica 7.1. Results:The study included 9 women with mean age of 53.25 ± 8.48 years.Pain decreased immediately after the sessions of RFM (p < 0.01).There was positive impact in the daily treatment of these patients,with a significant reduction in the FIQ score after 8 sessions (p =0.03). Conclusion: The results suggest that RFM therapy can be aphysiotherapist help for the treatment of patients with fibromyalgia.However, this study should be analyzed with caution, becausethere was no control group to ensure that positive results were duesolely to the treatment and not to other factors not considered bythe researchers.

Efeito da terapia por radiofrequência monopolar sobre a dor e capacidade funcional de mulheres com fibromialgia / Effect of monopolar radiofrequency on pain and functional capacity of women with fibromyalgia

Introdução: O tratamento através de eletroterapia é um recurso fisioterapêutico cada vez mais utilizado para a redução de quadros álgicos. No entanto, são escassos os estudos analisando os efeito da radiofrequência de modo contínuo não ablativo em pacientes com fibromialgia. Objetivo: Este estudo objetivou avaliar os efeitosda terapia por radiofrequência monopolar (RFM) na dor e no cotidiano de mulheres com fibromialgia. Método: Participaram deste estudo mulheres com diagnóstico clínico de fibromialgia, que foram submetidas a 8 sessões de RFM. Os atendimentos ocorreram 2 vezes por semana. Os resultados do tratamento foram avaliados pela Escala Visual Analógica (EVA) e pelo Fibromyalgia Impact Questionary (FIQ). Para comparar os resultados pré e pós tratamento utilizou-se o teste T Pareado do software Statistica 7.1. Resultados: Participaram deste estudo 9 mulheres com idade média de 53,25 (± 8,48) anos.Verificou-se alívio da dor imediatamente após as sessões de RFM (p <0,01). Houve repercussão positiva do tratamento no cotidiano dessas pacientes, visto que ocorreu significativa redução do escore do FIQ após as 8 sessões (p = 0,03). Conclusão: A partir dos resultados deste estudo, sugere-se que a terapia por RFM pode ser mais um aliado do fisioterapeuta para o tratamento de pacientes com fibromialgia. Contudo, os resultados desta pesquisa devem ser analisados com cautela, pois não houve um grupo controle para garantir que os resultados positivos deveram-se unicamente ao tratamento e não a outros fatores desconsiderados pelos pesquisadores.

Introduction: The treatment by electrotherapy is increasingly used as a therapeutic resource for reducing painful picture in Physical Therapy. However, there are few studies analyzing the effects of continuous and non-ablative radiofrequency in patients with fibromyalgia. Objective: This study evaluated the effects of monopolar radiofrequency on pain and daily life of women with fibromyalgia. Methods: The study included women diagnosed with fibromyalgia, who underwent eight sessions of RFM monopolar radiofrequency. The sessions occurred twice a week. The treatment results were evaluated by Visual Analogue Scale (VAS) and the Fibromyalgia Impact Questionnaire (FIQ). To compare the results before and after treatment, we used paired t-test from software Statistica 7.1. Results: The study included 9 women with mean age of 53.25 ± 8.48 years. Pain decreased immediately after the sessions of RFM (p < 0.01).There was positive impact in the daily treatment of these patients, with a significant reduction in the FIQ score after 8 sessions (p =0.03). Conclusion: The results suggest that RFM therapy can be an physiotherapist’s help for the treatment of patients with fibromyalgia. However, this study should be analyzed with caution, because there was no control group to ensure that positive results were due solely to the treatment and not to other factors not considered by the researchers.