Lung Ultrasound Assessment of Lung Hyperinflation in Patients with Stable COPD: An Effective Diagnostic Tool.

Purpose: To evaluate the degree of lung hyperinflation (LH) in patients with stable chronic obstructive pulmonary disease (COPD) by lung ultrasound score (LUS) and assess its value. Patients and Methods: We conducted a study of 149 patients with stable COPD and 100 healthy controls recruited by the Second Affiliated Hospital of Fujian Medical University. The pleural sliding displacement (PSD) was measured, the sliding of the pleura in different areas was observed, and LUS was calculated from both of them. The diaphragm excursion (DE), residual capacity (RV), total lung capacity (TLC), inspiratory capacity (IC) and functional residual capacity (FRC) were measured. We described the correlation between ultrasound indicators and pulmonary function indicators reflecting LH. Multiple linear regression analysis was used. The ROC curves of LUS and DE were drawn to evaluate their diagnostic efficacy, and De Long method was used for comparison. Results: (1) The LUS of patients with stable COPD were positively correlated with RV, TLC, RV/TLC and FRC and negatively correlated with IC and IC/TLC (r1=0.72, r2=0.41, r3=0.72, r4=0.70, r5=-0.56, r6=-0.65, P < 0.001). The correlation was stronger than that between DE at maximal deep inspiration and the corresponding pulmonary function indices (r1=-0.41, r2=-0.26, r3=-0.40, r4=-0.43, r5=0.30, r6=0.37, P < 0.001). (2) Multiple linear regression analysis showed that LUS were significantly correlated with IC/TLC and RV/TLC. (3) With IC/TLC<25% and RV/TLC>60% as the diagnostic criterion of severe LH, the areas under the ROC curves of LUS and DE at maximal deep inspiration for diagnosing severe LH were 0.914 and 0.385, 0.845 and 0.543, respectively (P < 0.001). Conclusion: The lung ultrasound score is an important parameter for evaluating LH. LUS is better than DE at maximal deep inspiration for diagnosing severe LH and is expected to become an effective auxiliary tool for evaluating LH.

Effect of a Conical-PEP Mask on Exercise in Subjects With COPD.

BACKGROUND: Dynamic hyperinflation (DH) is a major pathophysiology of COPD that is directly related to dyspnea and exercise intolerance. Positive expiratory pressure (PEP) might reduce DH and dyspnea during exercise, but at present, there is insufficient evidence to conclude whether it is beneficial for DH, dyspnea, and exercise capacity in COPD. METHODS: A randomized crossover trial with concealed allocation was conducted in 37 moderate to very severe subjects with COPD (34 males, age 66.6 ± 7.4 y, FEV1% of predicted 56.3 ± 13.7). The experimental condition was conical-PEP breathing with a PEP of around 5 cm H2O during a spot marching exercise at a constant speed, inducing 71 ± 9% age-predicted maximum heart rate to symptom limit or 25 min. The control condition was usual breathing. Exercise endurance time and end-exercise symptoms were recorded. Inspiratory capacity (IC) was measured pre-exercise and immediately post exercise. Cardiopulmonary function and breathlessness were monitored throughout the test and after 10 min of recovery. RESULTS: There were no complications or adverse effects during exercise with a conical-PEP mask. Conical-PEP showed longer exercise times than control (median 11.0 [interquartile range 7.7-17.0] min vs 8 [6.0-11.5] min, respectively, P < .001). Most stopped exercising because of breathlessness and leg fatigue. At the end of exercise, IC and breathlessness showed non-significant differences between the conditions, but breathlessness was significantly lower in conical-PEP (median 4 [1.5-5.0] than control 5 [3-6] on Borg scale at isotime for control [8 min]). CONCLUSIONS: Breathing with a 5 cm H2O conical-PEP mask improved exercise time (median 27.1% [0.6-52.9]) in subjects with COPD. The improvement in exercise with the conical-PEP mask was associated with slower development of breathlessness, possibly due to delays in DH development.

A comparative study of dynamic lung hyperinflation and tidal volume to total lung capacity ratios during exercise in patients with chronic respiratory disease and healthy individuals.

BACKGROUND: Current measures of tidal volume/forced vital capacity (VT/FVC) and VT/inspiratory capacity (VT/IC) at peak exercise cannot differentiate restrictive from obstructive ventilation patterns. This study aimed to investigate the utility of VT/total lung capacity (VT/TLC) as a marker for dynamic lung hyperinflation (DH) in patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). METHODS: 267 subjects were screened: 23 ILD, 126 COPD, and 33 healthy individuals were enrolled. Lung function tests and cardiopulmonary exercise tests with repeated IC maneuver were conducted and compared at three exercise efforts: unloaded, middle of exercise, and peak exercise. RESULTS: During exercise, ILD patients demonstrated normal end-expiratory lung volume/TLC (EELV/TLC) ratios, but elevated end-inspiratory lung volume/TLC (EILV/TLC) ratios, except for peak exercise. COPD patients exhibited elevated ratios for both EELV/TLC and EILV/TLC during exercise with a larger EELV/TLC ratio compared to ILD patients at peak exercise (p < 0.05). The VT/TLC ratio distinguished ILD, COPD, and healthy controls at peak exercise (p < 0.05). A VT/TLC ratio of ≤ 0.22 or ≥ 0.30 indicated airflow obstruction with hyperinflation or normal lung expansion, respectively (AUC: 0.74 or 0.88). Furthermore, VT/TLC outperformed VT/FVC and VT/IC in differentiating lung expansion between ILD and COPD during exercise (all p < 0.05). CONCLUSION: Exercise-induced DH was absent in ILD patients but observed in COPD patients. Excessive lung expansion occurred in all patients during exercise, except for limited expansion in ILD at peak exercise probably due to specific lung properties. VT/TLC can distinguish between restrictive, obstructive, and normal ventilatory patterns.

Cardiovascular effects of exercise induced dynamic hyperinflation in COPD patients-Dynamically hyperinflated and non-hyperinflated subgroups.

INTRODUCTION: An increase in respiratory rate and expiratory flow limitation can facilitate dynamic hyperinflation (DH), which may cause an element of the intrathoracic pressure in connection with the worsening of venous return, with negative effect on stroke volume (SV) and cardiac output (CO). It has been unclassified, whether poor circulatory adaptation to exercise can be attributed to DH or poor cardio-vascular performance itself in COPD. Only a subset of COPD patients exhibit dynamic hyperinflation during exercise. PATIENTS AND METHODS: We designed a study to show how lung mechanical and cardiovascular parameters change in hyperinflated and non-hyperinflated COPD patients during exercise with a new experimental set-up. Thirty-three COPD patients with similar severity of COPD and left ventricular performance (20 men, 13 women, mean±SD age: 65,36±6,95 years) participated. We measured the cardiovascular parameters with a non-invasive device (Finometer-pro) including the left ventricular ejection time index (LVETi) and estimated the change of DH with inspiratory capacity (IC) manoeuvres during exercise. RESULTS: Twenty-one subjects exhibited DH (DH group) and 12 did not (non-DH group). The measurement results were given in mean ± SD and difference between the values measured during maximal load and rest also (ΔX = Xmax.load-Xrest). ΔSV and ΔCO were significantly higher in non-DH vs. DH patients (ΔSV: non-DH 9,7 ± 13,22 ml vs. DH -3,6 ± 14,34 ml, p = 0.0142; ΔCO: non-DH 2,26 ± 1,46 l/min vs. DH 0,88 ± 1,35 l/min, p = 0.0024). LVETi was not different between the two groups. Calculated oxygen delivery (DO2) during maximal load was significantly higher in non-DH group. CONCLUSION: We concluded that worse cardiovascular adaptation to exercise of COPD patients can be associated with exercise-induced DH in a similar cardiovascular aged COPD group.

Analysis of the impact of different exercise methods on the physical health of obese adolescents / Análise do impacto entre diferentes métodos de exercício na saúde física de adolescentes obesos / Análisis del impacto entre diferentes métodos de ejercicio en la salud física de adolescentes obesos

ABSTRACT Introduction: The unregulated development in the current life pattern has strengthened obesity among adolescents, and this problem is becoming more serious. Objective: Compare the impact of two exercise methods on the physical health of obese adolescents. Methods: 24 obese adolescents (12 females; BMI>30% ± 3%; age concentrated between 10 and 16 years) were selected and divided into group I and group II for a 4-week experimental study, and changes in physical fitness and function were recorded. Results: After four weeks of aerobic exercise control (group I), waist circumference, hip circumference, skinfold thickness, and abdominal fold thickness were significantly reduced in boys (p<0.05), and girls' body shape indicators were significantly altered (p<0.05). After four weeks of aerobic exercise combined with resistance training (group II), the effects of weight, BMI, and body size were significant in boys and girls. Conclusion: Aerobic exercise can effectively improve the physical problems of obese adolescents. Under the same external conditions, the effect of aerobic exercise was shown to be more effective when combined with resistance training in the physical improvement of the analyzed group. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: O desenvolvimento desregrado no padrão de vida atual fortaleceu a obesidade entre os adolescentes e esse problema está se tornando cada vez mais grave. Objetivo: Comparar o impacto entre dois métodos de exercício na saúde física de adolescentes obesos. Métodos: Foram selecionados 24 adolescentes obesos (12 mulheres; IMC>30% ± 3%; idade concentrada entre 10 e 16 anos) e divididos no grupo I e no grupo II para um estudo experimental de 4 semanas, sendo registradas as alterações no condicionamento e função física. Resultados: Após 4 semanas de controle de exercício aeróbico (grupo I), a circunferência da cintura, circunferência do quadril, espessura da dobra cutânea e espessura da dobra abdominal foram significativamente reduzidas em meninos (p<0,05), e os indicadores de forma corporal das meninas foram significativamente alterados (p<0,05). Após 4 semanas de exercício aeróbico combinado com treinamento de resistência (grupo II), os efeitos do peso, IMC e tamanho do corpo foram significativos em meninos e meninas. Conclusão: O exercício aeróbico pode melhorar efetivamente os problemas físicos dos adolescentes obesos. Sob as mesmas condições externas, o efeito do exercício aeróbico demonstrou-se mais eficaz quando aliado ao treinamento de resistência na melhoria física do grupo analisado. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El desarrollo desordenado en el patrón de vida actual ha potenciado la obesidad entre los adolescentes y este problema es cada vez más grave. Objetivo: Comparar el impacto de dos métodos de ejercicio en la salud física de adolescentes obesos. Métodos: Se seleccionaron 24 adolescentes obesos (12 mujeres; IMC>30% ± 3%; edad concentrada entre 10 y 16 años) y se dividieron en el grupo I y el grupo II para un estudio experimental de 4 semanas, y se registraron los cambios en la aptitud física y la función. Resultados: Después de 4 semanas de control de ejercicio aeróbico (grupo I), la circunferencia de la cintura, la circunferencia de la cadera, el grosor de los pliegues cutáneos y el grosor de los pliegues abdominales se redujeron significativamente en los niños (p<0,05), y los indicadores de la forma corporal de las niñas se alteraron significativamente (p<0,05). Tras 4 semanas de ejercicio aeróbico combinado con entrenamiento de resistencia (grupo II), los efectos del peso, el IMC y el tamaño corporal fueron significativos en chicos y chicas. Conclusión: El ejercicio aeróbico puede mejorar eficazmente los problemas físicos de los adolescentes obesos. En las mismas condiciones externas, el efecto del ejercicio aeróbico se mostró más eficaz cuando se combinó con el entrenamiento de resistencia en la mejora física del grupo analizado. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Método JaPer. Una nueva estrategia para mejorar la capacidad inspiratoria. Ensayo Clínico Aleatorizado / JaPer Method. A new strategy to improve inspiratory capacity. Randomized clinical trial

Introducción: las enfermedades pulmonares pueden generar hospitalizaciones, estancias prolongadas, complicaciones e inclusive la muerte. Estas enfermedades repercuten negativamente en la capacidad inspiratoria y en la calidad de vida. Por lo tanto, el presente artículo pretende analizar los efectos del Método JaPer sobre la capacidad inspiratoria de los pacientes hospitalizados. Material y métodos: ensayo clínico aleatorizado inicialmente con 653 pacientes hospitalizados que pasó a 587 distribuidos en 2 grupos (Grupo experimental-GE: Método JaPer vs Grupo control-GC: uso convencional de inspirómetro volumétrico). Se determinó la capacidad inspiratoria máxima, caminata de los 6 minutos, antropometría y un cuestionario creado por los autores. Se aplicó un programa de entrenamiento de 2 semanas de 3 sesiones por día. Al GE se le aplicó el Método Japer con protocolo estandarizado para hacer ejercicios entre el 50 y el 80 % de la capacidad inspiratoria máxima del paciente y a los pacientes del GC se les realizó incentivo inspiratorio a inspiración máxima. Resultados: 587 pacientes (F:300 vs M:287) con edad promedio de 53.61±14.24 años, entre los cuales el 9.88 % tenía bajo peso, 17.89 % peso normal y el 27.26 % y 44.97 % sobrepeso y obesidad, respectivamente. Todos los participantes realizaron una caminata de 6 minutos para determinar los metros recorridos (GE: 387.70±47.59 vs GC: 371.30±49.10), velocidad (GE: 64.62±7.93 vs GC: 61.88±8.18) y el Vo2 estimado (GE: 9.96±0.79 vs GC: 9.69±0.82). Todas las variables y la capacidad inspiratoria máxima (GE: 1708.54±707.84 vs GC: 1448.83±692.79) determinaron pre y post entrenamiento. Conclusiones: el Método JaPer obtuvó mejores resultados en todas las variables evaluadas con diferencia significativa (p= <0.05) frente al grupo control, resaltando que la capacidad inspiratoria máxima aumentó en ambos grupos (GE:44 % vs GC:28 %; p= <0.05).

Introduction: Pulmonary diseases can generate hospitalizations, prolonged stays, complications and even death. These diseases have a negative impact on inspiratory capacity and quality of life. Therefore, this paper tries to analyze the effects of the JaPer method on the inspiratory capacity of hospitalized patients. Materials and methods: Randomized clinical trial initially with 653 patients, which went on to 587 hospitalized patients distributed in 2 groups (Experimental group: JaPer Method vs. Control group: Conventional use of volumetric inspirometer). Maximum inspiratory capacity, 6-minute walk, anthropometry, and a questionnaire created by the authors were determined. A 2-week training program of 3 sessions per day was applied. The GE applied the Japer Method with a standardized protocol to exercise between 50 and 80% of the patient's maximum inspiratory capacity, and the CG underwent inspiratory incentive at maximum inspiration. Results: 587 patients (F:300 vs M:287) with a mean age of 53.61±14.24 years and 9.88% of the population were underweight, 17.89% normal weight and 27.26% and 44.97% overweight and obese, respectively. All participants performed a 6-minute walk to determine meters traveled (GE: 387.70±47.59 vs CG: 371.30±49.10), speed (GE: 64.62±7.93 vs CG: 61.88±8.18) and estimated VO2 (GE: 9.96 ±0.79 vs CG: 9.69±0.82). All variables and maximal inspiratory capacity (GE: 1708.54±707.84 vs CG: 1448.83±692.79) were determined before and after training. Conclusions: The JaPer method obtained better results in all the variables evaluated with a significant difference (p=<0.05) compared to the control group. Highlighting that the maximum inspiratory capacity increased in both groups (GE:44% vs CG:28%; p=<0.05).

Una propuesta para protocolizar el incentivo inspiratorio / A proposal to protocolize the inspiratory incentive

Los autores nos presentan en este artículo un ensayo clínico aleatorizado, cuyo objetivo es analizar los efectos del método JaPer sobre la capacidad inspiratoria de los pacientes hospitalizados. La primera inquietud a resolver es ¿En qué consiste el método JaPer y cuál es su finalidad? Pues bien, este método debe el nombre a su creador, quien es también uno de los autores del estudio. Se entiende como un protocolo de fisioterapia respiratoria que hace parte de la rehabilitación pulmonar y tiene como finalidad, realizar una prescripción del ejercicio a porcentajes de entrenamiento del 50 al 80 % de la capacidad inspiratoria máxima del participante, determinada a través del inspirómetro incentivo, que además funciona como instrumento de intervención, asociado a una serie de ejercicios respiratorios.

In this article, the authors present a randomized clinical trial, whose objective is to analyze the effects of the JaPer method on the inspiratory capacity of hospitalized patients. The first concern to resolve is what is the JaPer method and what is its purpose? Well, this method owes its name to its creator, who is also one of the authors of the study. It is understood as a respiratory physiotherapy protocol that is part of pulmonary rehabilitation and its purpose is to carry out an exercise prescription at training percentages of 50 to 80% of the maximum inspiratory capacity of the participant, determined through the incentive spirometer, which it also works as an intervention instrument, associated with a series of breathing exercises.

Tidal volume expandability affected by flow, dynamic hyperinflation, and quasi-fixed inspiratory time in patients with COPD and healthy individuals.

Exertional dyspnea (ED) and impaired exercise performance (EP) are mainly caused by dynamic hyperinflation (DH) in chronic obstructive pulmonary disease (COPD) patients by constraining tidal volume expansion at peak exercise (VTpeak). As VTpeak is the product of inspiratory time (TIpeak) and flow (VT/TIpeak), it was hypothesized that VTpeak and VTpeak/total lung capacity (VTpeak/TLC) may be affected by TIpeak and VT/TIpeak. Hence, the study investigated the (1) effect of TIpeak and VT/TIpeak on VTpeak expansion, (2) factors associated with TIpeak, expiratory time (TEpeak), VT/TIpeak, and VTpeak/TLC, and (3) relationships between VT/TIpeak and VTpeak/TLC with ED and EP in COPD patients and controls. The study enrolled 126 male stable COPD patients and 33 sex-matched controls. At peak exercise, TIpeak was similar in all subjects (COPD versus controls, mean ± SD: 0.78 ± 0.17 s versus 0.81 ± 0.20 s, p = NS), whereas the COPD group had lower VT/TIpeak (1.71 ± 0.49 L/s versus 2.58 ± 0.69 L/s, p < .0001) and thus the COPD group had smaller VTpeak (1.31 ± 0.34 L versus 2.01 ± 0.45 L,p < .0001) and VTpeak/TLC (0.22 ± 0.06 vs 0.33 ± 0.05, p < .0001). TIpeak, TEpeak, and VT/TIpeak were mainly affected by exercise effort, whereas VTpeak/TLC was not. TEpeak, VT/TIpeak, and VTpeak/TLC were inversely changed by impaired lung function. TIpeak was not affected by lung function. Dynamic hyperinflation did not occur in the controls, however, VTpeak/TLC was strongly inversely related to DH (r = -0.79) and moderately to strongly related to lung function, ED, and EP in the COPD group. There was a slightly stronger correlation between VTpeak/TLC with ED and EP than VT/TIpeak in the COPD group (|r| = 0.55-0.56 vs 0.38-0.43). In summary, TIpeak was similar in both groups and the key to understanding how flow affects lung expansion. However, the DH volume effect was more important than the flow effect on ED and EP in the COPD group.

Physiological predictors of morbidity and mortality in COPD: the relative importance of reduced inspiratory capacity and inspiratory muscle strength.

Low resting inspiratory capacity (IC) and low maximal inspiratory pressure (MIP) have previously been linked to exertional dyspnea, exercise limitation, and poor survival in chronic obstructive pulmonary disease (COPD). The interaction and relative contributions of these two related variables to important clinical outcomes are unknown. The objective of the current study was to examine the interaction between resting IC and MIP (both % predicted), exertional dyspnea, exercise capacity, and long-term survival in patients with COPD. Two hundred and eighty-five patients with mild to advanced COPD completed standard lung function testing and a cycle cardiopulmonary exercise test. Multiple regression determined predictors of the exertional dyspnea-ventilation slope and peak oxygen uptake (V̇o2peak). Cox regression determined predictors of 10-year mortality. IC was associated with the dyspnea-ventilation slope (standardized ß = -0.42, P < 0.001), whereas MIP was excluded from the regression model (P = 0.918). IC and MIP were included in the final model to predict V̇o2peak. However, the standardized ß was greater for IC (0.43) than MIP (0.22). After adjusting for age, sex, body mass index, cardiovascular risk, airflow obstruction, and diffusing capacity, resting IC was independently associated with 10-year all-cause mortality (hazard ratio = 1.25, confidence interval5%-95% = 1.16-1.34, P < 0.001), whereas MIP was excluded from the final model (all P = 0.829). Low resting IC was consistently linked to heightened dyspnea intensity, low V̇o2peak, and worse survival in COPD even after accounting for airway obstruction, inspiratory muscle strength, and diffusing capacity. These results support the use of resting IC as an important physiological biomarker closely linked to key clinical outcomes in COPD.NEW & NOTEWORTHY To our knowledge, this study is the first to show an independent association between low resting inspiratory capacity (IC) and, severe exertional dyspnea, exercise limitation, and increased mortality risk, after accounting for the severity of airway obstruction, inspiratory muscle strength, and diffusing capacity. These results support the use of resting IC as an important independent physiological biomarker closely linked to key clinical outcomes in COPD.

Intercostal muscle oxygenation and expiratory loaded breathing at rest: Respiratory pattern effect.

In patients with airway obstruction, an increase in breathing frequency at rest is commonly associated with a dynamic hyperinflation (DH). In such a situation, intercostal muscle oxygenation may be disturbed. This hypothesis was examined in a context of simulated airway obstruction in healthy subjects. After a control period of 5 min, twelve participants (20 ± 2 years) breathed at rest through a 20-cmH2O expiratory threshold load, either by increasing or reducing their respiratory rate (ETLF+ or ETLF). Tissue saturation index (TSI) and concentration changes in oxyhaemoglobin (oxy[Hb+Mb]) were measured as well as cardiorespiratory variables. Inspiratory capacity was decreased in ETLF+ (p < 0.001) and correlated with dyspnea. An increase in oxy[Hb+Mb] occurred in ETLF+ that was higher than in ETLF (p < 0.01). TSI was not different between conditions. In healthy subjects at rest, an increase in respiratory rate during a simulated obstruction with an expiratory threshold load resulted in paradoxical response with DH emergence while intercostal muscle oxygenation was preserved.

Investigation of dynamic hyperinflation and its relationship with exercise capacity in children with bronchiectasis.

BACKGROUND AND AIM: Dynamic hyperinflation (DH) is a major contributor to exercise intolerance in patients with obstructive lung diseases. However, it has not been investigated in children with bronchiectasis (BE). We aimed to investigate dynamic ventilatory responses and their influence on functional exercise capacity in children with BE. METHODS: Forty children with BE (mean forced expiratory volume in 1 s [FEV1 ] = 78 ± 19%pred) were included. Six-minute walk test (6MWT) was conducted using Spiropalm 6MWT® for evaluating dynamic ventilatory responses including inspiratory capacity (IC), minute ventilation (VE), breathing reserve (BR) and respiratory rate (RR). A decrease of ≥100 ml in IC during exertion was defined as DH. Also, spirometry was performed, and peripheral muscle strength were measured. RESULTS: Twenty patients (50%) developed DH, and four patients (10%) were ventilatory limited (BR < %30) during 6MWT. There was a 176 [100-590] ml decrease in IC after exertion in patients with DH. DH did not correlate to clinical or functional indicators of the disease, except for an increase in RR (∆RR) during exertion. High ∆RR was associated with presence of DH (rpb = 0.390; p < 0.05). Clinical features, peripheral muscle strength, and Spiropalm 6MWT metrics including 6MWT distance did not differ between patients with and without DH. Univariate analysis revealed FVC% (R = 0.340), VEpeak (R = 0.565), quadriceps strength (R = 0.698) and handgrip strength (R = 0.711) were the only predictors of 6MWT distance (p < 0.05). CONCLUSION: Although DH is common in children with BE, the severity of DH is rather low and may not seem to affect functional exercise capacity. However, peripheral muscle strength was a major contributor to functional exercise capacity.

A reappraisal of inspiratory capacity in chronic obstructive pulmonary disease: clinical correlates and role of long-acting muscarinic antagonists and long-acting ß2 agonists.

INTRODUCTION: In patients with chronic obstructive pulmonary disease (COPD), static and dynamic hyperinflation, together with expiratory flow limitation and gas exchange abnormalities, is one of the major causes of dyspnea, decreased exercise performance and ventilatory failure. An increase in functional residual capacity (FRC) is accompanied by a decrease in inspiratory capacity (IC), which is a volume readily available, repeatable, and simple to measure with any spirometer. Changes in IC and FRC after bronchodilation, contrary to changes in FEV1, have been closely associated with improvements in dyspnea and exercise performance. We systematically searched PubMed and Embase databases for clinical trials that assessed the effects of dual bronchodilation on inspiratory capacity in patients with COPD. AREAS COVERED: Despite their pivotal role in COPD, IC and static volumes have rarely been considered as primary outcomes in randomized clinical trials assessing the efficacy of bronchodilators. Available studies on dual bronchodilation have shown a significant and persistent positive impact on IC focusing mainly on patients with moderate-to-severe COPD, whereas dynamic hyperinflation is also present at milder disease stages. EXPERT OPINION: This narrative review discusses the pathophysiological and clinical importance of measuring IC in patients with COPD and how IC can be modified by maximizing bronchodilation combining long-acting muscarinic antagonists and long-acting ß2 agonists.

Patients with Chronic Obstructive Pulmonary Disease Can Accurately Perform Home-Based Measurements of Inspiratory Capacity and Dynamic Hyperinflation.

Home-based lung function measurements can be used to capture day-to-day variations in symptoms in patients with chronic obstructive pulmonary disease (COPD). Although dynamic hyperinflation (DH) is clinically relevant, existing home-based measurements do not include its assessment. DH can be measured through inspiratory capacity (IC) measurements before and after metronome-paced tachypnea test (MPT). The goal of this study is to determine the accuracy of unsupervised home-based IC and DH measurements in COPD.Sixteen COPD patients performed IC and DH measurements during 4 home visits. Visit 1 was considered a training session. During all visits supervised and unsupervised IC at rest (ICREST) and after MPT (ICMPT) were measured. DH was calculated as the difference between ICREST and ICMPT, and as a percentage of ICREST. Bland-Altman analyses and ANOVA tests were performed to determine the effect of supervision and repeated measures over time.The biases between supervised and unsupervised ICREST, ICMPT, ΔIC and ΔIC% were 0.007 L, 0.007 L, 0 mL and -0.09% in the last visit, respectively. Limits of agreement of ICREST and ΔIC% decreased from ±0.261 mL to ±0.201 mL, and from ±13.84% to ±10.81% between visit 1 and 4, respectively. No significant effect of supervision or over time was found.After a robust training and a learning phase, COPD patients are able to perform IC measurements in an accurate manner in both rest and after MPT. This yield accurate assessment of DH, in an unsupervised home-based setting.

Perceptions of Noninvasive Ventilation During Exercise in Noninvasive Ventilation-Naïve Patients With COPD.

BACKGROUND: The perceptions of using noninvasive ventilation (NIV) during exercise in patients with COPD who are naïve to NIV is unknown. The present study aimed to examine the perceptions of using NIV during exercise in people with COPD and to determine the relationship between patient perceptions with both baseline patient characteristics and exercise outcomes. METHODS: During a trial examining the effect of NIV during exercise on dynamic hyperinflation in people with COPD who were naïve to NIV, participants completed a 5-point Likert scale questionnaire (scored strongly disagree -2 to strongly agree +2) before and after using NIV during exercise and a semi-structured interview after using NIV during exercise. RESULTS: Eighteen participants, mean age (SD) 69 (7) y, FEV1/FVC 0.44 (0.08), FEV1 39 (7)% predicted, completed the study. Prior to exercise with NIV, participants were neutral about NIV, (mean [SD]) (0.67[0.84]). After exercise with NIV, participants felt that NIV made breathing easier (1.00 [0.77]) and that it helped exercise (1.06 [0.64]). There were moderate correlations between feeling that NIV was comfortable or effective and a change in exercise endurance time (ρ = - 0.588, P = .02), isotime inspiratory capacity (ρ = 0.488, P = .03), and measures of resting hyperinflation (ρ = 0.603, \P = .02). Interviews revealed that despite feeling comfortable using NIV during exercise, NIV might be too complicated for patients to manage outside a supervised environment. CONCLUSIONS: Individuals with COPD, naïve to NIV, and using NIV during exercise for the first time reported a positive effect of NIV on breathlessness and exercise performance. Participants' perceived benefit of NIV correlated moderately with increased endurance time and resting hyperinflation and with a reduction in dynamic hyperinflation during exercise, suggesting that patient reports could also aid selection of those who will benefit from NIV during exercise.

The relationship between peak inspiratory flow and hand grip strength measurement in men with mild chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) decreases quality of life and muscular strength. Inspiratory flow is important for inhalants in the bronchi but is complicated to measure in routine practice. We hypothesized that hand grip strength (HGS) would correlate with inhalation rate in patients with mild COPD. METHODS: The COPD patients were recruited at the St. Marianna University School of Medicine, Yokohama Seibu Hospital, from 2015 to 2018. We measured peak inspiratory flow (PIF) through an In-Check flow meter attached with Diskus [PIF(D)] and Turbuhaler [PIF(T)] inhalers. The 6-min walking test (6MWT), and the fraction of exhaled nitric oxide (FENO), spirometry, HGS, or forced oscillation technique (FOT) parameters were measured. RESULTS: Forty-four subjects were enrolled. All were men, with a mean age (± SD) of 77.8 ± 9.36 years. Thirty-nine patients had mild COPD. PIF(D) was 110 (80, 140) L/min (median, interquartile range), PIF(T) was 80 (70, 90) L/min, and HGS was 28.7 (13.8, 43.6) kgf. PIF(D) and PIF(T) were significantly correlated (r = 0.443, p = 0.003). PIF(D) was significantly correlated with age (r = - 0.327, p = 0.030) and HGS (r = 0.326, p = 0.031). PIF(T) was significantly correlated with age (r = - 0.328, p = 0.030), FVC (r = 0.351, p = 0.019), 6MWT distance (r = 0.392, p = 0.011), and HGS (r = 0.328, p = 0.030). CONCLUSION: HGS might be more useful for predicting PIF than other parameters. Also, elderly COPD patients need to be taught inhaled methods carefully.

Compensatory responses to increased mechanical abnormalities in COPD during sleep.

PURPOSE: To assess whether night-time increases in mechanical loading negatively impact respiratory muscle function in COPD and whether compensatory increases in inspiratory neural drive (IND) are adequate to stabilize ventilatory output and arterial oxygen saturation, especially during sleep when wakefulness drive is withdrawn. METHODS: 21 patients with moderate-to-severe COPD and 20 age-/sex-matched healthy controls (CTRL) participated in a prospective, cross-sectional, one-night study to assess the impact of COPD on serial awake, supine inspiratory capacity (IC) measurements and continuous dynamic respiratory muscle function (esophageal manometry) and IND (diaphragm electromyography, EMGdi) in supine sleep. RESULTS: Supine inspiratory effort and EMGdi were consistently twice as high in COPD versus CTRL (p < 0.05). Despite overnight increases in awake total airways resistance and dynamic lung hyperinflation in COPD (p < 0.05; not in CTRL), elevated awake EMGdi and respiratory effort were unaltered in COPD overnight. At sleep onset (non-rapid eye movement sleep, N2), EMGdi was decreased versus wakefulness in COPD (- 43 ± 36%; p < 0.05) while unaffected in CTRL (p = 0.11); however, respiratory effort and arterial oxygen saturation (SpO2) were unchanged. Similarly, in rapid eye movement (stage R), sleep EMGdi was decreased (- 38 ± 32%, p < 0.05) versus wakefulness in COPD, with preserved respiratory effort and minor (2%) reduction in SpO2. CONCLUSIONS: Despite progressive mechanical loading overnight and marked decreases in wakefulness drive, inspiratory effort and SpO2 were well maintained during sleep in COPD. Preserved high inspiratory effort during sleep, despite reduced EMGdi, suggests continued (or increased) efferent activation of extra-diaphragmatic muscles, even in stage R sleep. CLINICAL TRIAL INFORMATION: The COPD data reported herein were secondary data (Placebo arm only) obtained through the following Clinical Trial: "Effect of Aclidinium/Formoterol on Nighttime Lung Function and Morning Symptoms in Chronic Obstructive Pulmonary Disease" ( https://clinicaltrials.gov/ct2/show/NCT02429765 ; NCT02429765).

The role of inspiratory capacity and tidal flow in diagnosing exercise ventilatory limitation in Cystic Fibrosis.

BACKGROUND: Exercise ventilatory limitation conventionally defined by reduced breathing reserve (BR) may underestimate the effect of lung disease on exercise capacity in patients with mild to moderate obstructive lung diseases. OBJECTIVE: To investigate whether ventilatory limitation may be present despite a normal BR in Cystic Fibrosis (CF). METHODS: Twenty adult CF patients (age 16-58y) with a wide range of pulmonary obstruction severity completed a symptom-limited incremental exercise test on a cycle ergometer. Operating lung volumes were derived from inspiratory capacity (IC) measurement during exercise and exercise tidal flow volume loop analysis. RESULTS: six patients had a severe airway obstruction (FEV1<45% predicted) and conventional evidence of ventilatory limitation (low BR). Fourteen patients had mild to moderate-severe airway obstructive (FEV1 46-103% predicted), and a normal BR [12-62 L/min, BR% (17-40)]. However, dynamic respiratory mechanics demonstrated that even CF patients with mild to moderate-severe lung disease had clear evidence of ventilatory limitation during exercise. IC was decreased by (median) 580 ml (range 90-1180 ml) during exercise, indicating dynamic hyperinflation. Inspiratory reserve volume at peak exercise was 445 ml (241-1350 ml) indicating mechanical constraint on the respiratory system. The exercise tidal flow met or exceeded the expiratory boundary of the maximal flow volume loop over 72% of the expiratory volume (range 40-90%), indicating expiratory flow limitation. CONCLUSION: Reduced BR as a sole criterion underestimates ventilatory limitation during exercise in mild to moderate-severe CF patients. Assessment of dynamic respiratory mechanics during exercise revealed ventilatory limitation, present even in patients with mild obstruction.

Investigation of Repeatability of Peak Nasal Inspiratory Flow Rate Measurements Under Baseline Conditions and After Administration of 0.05% Oxymetazoline.

OBJECTIVES: Peak nasal inspiratory flow (PNIF) measurement is an inexpensive and user-friendly method to assess nasal patency. However, the repeatability of PNIF measurements, as well as the threshold value of a change in PNIF, which can be considered significant remain unclear. This study aims to investigate the repeatability of PNIF measurements and the change in PNIF after the administration of 0.05% oxymetazoline. METHODS: Repeated measurements of PNIF (Clement Clarke In-Check nasal inspiratory flow meter; Clement Clarke International, Ltd, Harlow, Essex, UK) were obtained in 333 healthy volunteers (174 women). Based on age, participants were categorized into three groups (6-7 years, 13-14 years, and 20-45 years). We obtained five measurements in each participant. PNIF was remeasured in 294 subjects 30 min after administration of 0.05% oxymetazoline. The variability in PNIF measurements was assessed using the coefficient of variation (CV = standard deviation × 100%/mean). RESULTS: The first four PNIF measurements significantly differed from each other. The difference in PNIF measurements ceased to be statistically significant only between the fourth and fifth measurements (p = 0.19). PNIF repeatability was acceptable; the median CV was 15.5% (0-66), which did not significantly differ between age groups. The administration of 0.05% oxymetazoline led to a statistically significant increase in the PNIF value by 14.3% (-45, 157%) (p = 0.000000). CONCLUSIONS: 1. No statistically significant difference was observed in PNIF values only between the fourth and fifth measurements; therefore, at least three measurements are essential to draw meaningful conclusions. 2. PNIF measurements were satisfactorily characterized by a relatively low CV (15%). 3. The administration of 0.05% oxymetazoline led to an increase in PNIF by approximately 14% over the baseline value.

Slow chest compression acutely reduces dynamic hyperinflation in people with chronic obstructive pulmonary disease: a randomized cross-over trial.

BACKGROUND: Strategies to minimize dynamic hyperinflation (DH) and dyspnea, such as slow chest compression (SCC), are relevant in people with chronic obstructive pulmonary disease (COPD). OBJECTIVES: To analyze the acute effects of SCC after exercise on DH and dyspnea in people with COPD and to identify responders to the technique. METHODS: This is a cross-over study with 40 patients. Two six-minute step tests (6MSTs) were performed followed by a one-minute application of SCC (6MSTSCC) or rest (6MSTCONTROL), at random. End-expiratory lung volume (EELV) and dyspnea were assessed. A difference ≥76 ml in ΔEELV between SCC and control characterized the responders. RESULTS: The performance in 6MSTSCC and 6MSTCONTROL were similar. There was a greater reduction in EELV after 6MSTSCC compared to 6MSTCONTROL (124 ± 193 ml vs. 174 ± 183 ml; p = .049), while there was no difference in change in dyspnea between the SCC and control groups. Twenty-one participants were SCC responders and had higher functional residual capacity [FRC: 5.36 ± 1.09 vs. 4.58 ± 0.94; p = .02; cutoff point: 4.56; sensitivity = 76%; specificity = 53%; AUC = 0.71 (95%CI: 0.54 to 0.87); p = .02]. CONCLUSION: SCC applied immediately after exercise reduced DH, but did not reduce dyspnea in people with COPD. The technique is beneficial only for some patients and FRC can help to identify them.