RESUMEN
Pulmonary rehabilitation (PR) remains grossly underutilised by suitable patients worldwide. We investigated whether home-based maintenance tele-rehabilitation will be as effective as hospital-based maintenance rehabilitation and superior to usual care in reducing the risk for acute chronic obstructive pulmonary disease (COPD) exacerbations, hospitalisations and emergency department (ED) visits.Following completion of an initial 2-month PR programme this prospective, randomised controlled trial (between December 2013 and July 2015) compared 12 months of home-based maintenance tele-rehabilitation (n=47) with 12 months of hospital-based, outpatient, maintenance rehabilitation (n=50) and also to 12 months of usual care treatment (n=50) without initial PR.In a multivariate analysis during the 12-month follow-up, both home-based tele-rehabilitation and hospital-based PR remained independent predictors of a lower risk for 1) acute COPD exacerbation (incidence rate ratio (IRR) 0.517, 95% CI 0.389-0.687, and IRR 0.635, 95% CI 0.473-0.853), respectively, and 2) hospitalisations for acute COPD exacerbation (IRR 0.189, 95% CI 0.100-0.358, and IRR 0.375, 95% CI 0.207-0.681), respectively. However, only home-based maintenance tele-rehabilitation and not hospital-based, outpatient, maintenance PR was an independent predictor of ED visits (IRR 0.116, 95% CI 0.072-0.185).Home-based maintenance tele-rehabilitation is equally effective as hospital-based, outpatient, maintenance PR in reducing the risk for acute COPD exacerbation and hospitalisations. In addition, it encounters a lower risk for ED visits, thereby constituting a potentially effective alternative strategy to hospital-based, outpatient, maintenance PR.
Asunto(s)
Servicio de Urgencia en Hospital , Servicios de Atención de Salud a Domicilio , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/rehabilitación , Telerrehabilitación/métodos , Enfermedad Aguda , Anciano , Progresión de la Enfermedad , Ejercicio Físico , Femenino , Hospitalización , Hospitales , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pacientes Ambulatorios , Cooperación del Paciente , Valor Predictivo de las Pruebas , Calidad de Vida , Proyectos de Investigación , RiesgoAsunto(s)
Actividades Cotidianas , Entrenamiento de Intervalos de Alta Intensidad , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/rehabilitación , Anciano , Gasto Cardíaco , Tolerancia al Ejercicio , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fuerza Muscular , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Resultado del TratamientoRESUMEN
In patients with chronic obstructive pulmonary disease (COPD), reduced levels of daily physical activity are associated with the degree of impairment in lung, peripheral muscle, and central hemodynamic function. There is, however, limited evidence as to whether limitations in tidal volume expansion also, importantly, determine daily physical activity levels in COPD. Eighteen consecutive patients with COPD [9 active (forced expiratory volume in 1 s, FEV1: 1.59 ± 0.64 l) with an average daily movement intensity >1.88 m/s(2) and 9 less active patients (FEV1: 1.16 ± 0.41 l) with an average intensity <1.88 m/s(2)] underwent a 4-min treadmill test at a constant speed corresponding to each individual patient's average movement intensity, captured by a triaxial accelerometer during a preceding 7-day period. When chest wall volumes, captured by optoelectronic plethysmography, were expressed relative to comparable levels of minute ventilation (ranging between 14.5 ± 4.3 to 33.5 ± 4.4 l/min), active patients differed from the less active ones in terms of the lower increase in end-expiratory chest wall volume (by 0.15 ± 0.17 vs. 0.45 ± 0.21 l), the greater expansion in tidal volume (by 1.76 ± 0.58 vs. 1.36 ± 0.24 l), and the larger inspiratory reserve chest wall volume (IRVcw: by 0.81 ± 0.25 vs. 0.39 ± 0.27 l). IRVcw (r(2) = 0.420), expiratory flow (r(2) change = 0.174), and Borg dyspnea score (r(2) change = 0.123) emerged as the best contributors, accounting for 71.7% of the explained variance in daily movement intensity. Patients with COPD exhibiting greater ability to expand tidal volume and to maintain adequate inspiratory reserve volume tend to be more physically active. Thus interventions aiming at mitigating restrictions on operational chest wall volumes are expected to enhance daily physical activity levels in COPD.
Asunto(s)
Ejercicio Físico/fisiología , Pulmón/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Volumen de Ventilación Pulmonar/fisiología , Acelerometría , Anciano , Disnea/fisiopatología , Prueba de Esfuerzo , Femenino , Volumen Espiratorio Forzado/fisiología , Humanos , Masculino , Persona de Mediana Edad , Mecánica Respiratoria/fisiologíaRESUMEN
In chronic obstructive pulmonary disease (COPD), daily physical activity is reported to be adversely associated with the magnitude of exercise-induced dynamic hyperinflation and peripheral muscle weakness. There is limited evidence whether central hemodynamic, oxygen transport, and peripheral muscle oxygenation capacities also contribute to reduced daily physical activity. Nineteen patients with COPD (FEV1, 48 ± 14% predicted) underwent a treadmill walking test at a speed corresponding to the individual patient's mean walking intensity, captured by a triaxial accelerometer during a preceding 7-day period. During the indoor treadmill test, the individual patient mean walking intensity (range, 1.5 to 2.3 m/s2) was significantly correlated with changes from baseline in cardiac output recorded by impedance cardiography (range, 1.2 to 4.2 L/min; r = 0.73), systemic vascular conductance (range, 7.9 to 33.7 ml·min(-1)·mmHg(-1); r = 0.77), systemic oxygen delivery estimated from cardiac output and arterial pulse-oxymetry saturation (range, 0.15 to 0.99 L/min; r = 0.70), arterio-venous oxygen content difference calculated from oxygen uptake and cardiac output (range, 3.7 to 11.8 mlO2/100 ml; r = -0.73), and quadriceps muscle fractional oxygen saturation assessed by near-infrared spectrometry (range, -6 to 23%; r = 0.77). In addition, mean walking intensity significantly correlated with the quadriceps muscle force adjusted for body weight (range, 0.28 to 0.60; r = 0.74) and the ratio of minute ventilation over maximal voluntary ventilation (range, 38 to 89%, r = -0.58). In COPD, in addition to ventilatory limitations and peripheral muscle weakness, intensity of daily physical activity is associated with both central hemodynamic and peripheral muscle oxygenation capacities regulating the adequacy of matching peripheral muscle oxygen availability by systemic oxygen transport.
Asunto(s)
Actividad Motora/fisiología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Anciano , Prueba de Esfuerzo , Femenino , Hemodinámica , Humanos , Pierna , Masculino , Persona de Mediana Edad , Fuerza Muscular , Oxígeno/sangre , Consumo de Oxígeno , Enfermedad Pulmonar Obstructiva Crónica/sangre , Músculo Cuádriceps/fisiopatología , Caminata/fisiologíaRESUMEN
Some reports suggest that heliox breathing during exercise may improve peripheral muscle oxygen availability in patients with chronic obstructive pulmonary disease (COPD). Besides COPD patients who dynamically hyperinflate during exercise (hyperinflators), there are patients who do not hyperinflate (non-hyperinflators). As heliox breathing may differently affect cardiac output in hyperinflators (by increasing preload and decreasing afterload of both ventricles) and non-hyperinflators (by increasing venous return) during exercise, it was reasoned that heliox administration would improve peripheral muscle oxygen delivery possibly by different mechanisms in those two COPD categories. Chest wall volume and respiratory muscle activity were determined during constant-load exercise at 75% peak capacity to exhaustion, while breathing room air or normoxic heliox in 17 COPD patients: 9 hyperinflators (forced expiratory volume in 1 s = 39 ± 5% predicted), and 8 non-hyperinflators (forced expiratory volume in 1 s = 48 ± 5% predicted). Quadriceps muscle blood flow was measured by near-infrared spectroscopy using indocyanine green dye. Hyperinflators and non-hyperinflators demonstrated comparable improvements in endurance time during heliox (231 ± 23 and 257 ± 28 s, respectively). At exhaustion in room air, expiratory muscle activity (expressed by peak-expiratory gastric pressure) was lower in hyperinflators than in non-hyperinflators. In hyperinflators, heliox reduced end-expiratory chest wall volume and diaphragmatic activity, and increased arterial oxygen content (by 17.8 ± 2.5 ml/l), whereas, in non-hyperinflators, heliox reduced peak-expiratory gastric pressure and increased systemic vascular conductance (by 11.0 ± 2.8 ml·min(-1)·mmHg(-1)). Quadriceps muscle blood flow and oxygen delivery significantly improved during heliox compared with room air by a comparable magnitude (in hyperinflators by 6.1 ± 1.3 ml·min(-1)·100 g(-1) and 1.3 ± 0.3 ml O(2)·min(-1)·100 g(-1), and in non-hyperinflators by 7.2 ± 1.6 ml·min(-1)·100 g(-1) and 1.6 ± 0.3 ml O(2)·min(-1)·100 g(-1), respectively). Despite similar increase in locomotor muscle oxygen delivery with heliox in both groups, the mechanisms of such improvements were different: 1) in hyperinflators, heliox increased arterial oxygen content and quadriceps blood flow at similar cardiac output, whereas 2) in non-hyperinflators, heliox improved central hemodynamics and increased systemic vascular conductance and quadriceps blood flow at similar arterial oxygen content.
Asunto(s)
Ejercicio Físico/fisiología , Helio/administración & dosificación , Oxígeno/administración & dosificación , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Músculo Cuádriceps/efectos de los fármacos , Arterias/efectos de los fármacos , Arterias/metabolismo , Fenómenos Biomecánicos/efectos de los fármacos , Gasto Cardíaco/efectos de los fármacos , Gasto Cardíaco/fisiología , Prueba de Esfuerzo/métodos , Espiración/efectos de los fármacos , Espiración/fisiología , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Helio/metabolismo , Hemodinámica/efectos de los fármacos , Hemodinámica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Actividad Motora/efectos de los fármacos , Oxígeno/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Músculo Cuádriceps/irrigación sanguínea , Músculo Cuádriceps/metabolismo , Músculo Cuádriceps/fisiopatología , Flujo Sanguíneo Regional/efectos de los fármacos , Flujo Sanguíneo Regional/fisiología , Músculos Respiratorios/efectos de los fármacos , Músculos Respiratorios/metabolismo , Músculos Respiratorios/fisiopatología , Pared Torácica/efectos de los fármacos , Pared Torácica/metabolismoRESUMEN
In this study, we wished to determine whether the observed reduction in quadriceps muscle oxygen availability, reported during repetitive bouts of isometric exercise in simulated sailing efforts (i.e. hiking), is because of restricted muscle blood flow. Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3-min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts. The blood flow index (BFI) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye, while cardiac output was determined from impedance cardiography. At equivalent cardiac outputs (ranging from 10.3±0.5 to 14.8±0.86 L · min(-1)), the increase from baseline in vastus lateralis BFI across the three hiking bouts (from 1.1±0.2 to 3.1±0.6 nM · s(-1)) was lower (P = 0.036) than that seen during the three cycling bouts (from 1.1±0.2 to 7.2±1.4 nM · s(-1)) (Cohen's d: 3.80 nM · s(-1)), whereas the increase from baseline in deoxygenated haemoglobin (by â¼17.0±2.9 µM) (an index of tissue oxygen extraction) was greater (P = 0.006) during hiking than cycling (by â¼5.3±2.7 µM) (Cohen's d: 4.17 µM). The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles.
Asunto(s)
Ejercicio Físico/fisiología , Consumo de Oxígeno , Oxígeno/metabolismo , Músculo Cuádriceps/fisiología , Deportes/fisiología , Adulto , Ciclismo/fisiología , Gasto Cardíaco , Impedancia Eléctrica , Prueba de Esfuerzo , Hemoglobinas/metabolismo , Humanos , Masculino , Músculo Cuádriceps/irrigación sanguínea , Músculo Cuádriceps/metabolismo , Flujo Sanguíneo Regional , Espectroscopía Infrarroja Corta , Caminata/fisiología , Adulto JovenRESUMEN
Asynchronous breathing movements may be observed in the presence of pulmonary disease, such as chronic obstructive pulmonary disease (COPD). This study was undertaken in an attempt to propose a reliable methodology to quantify this asynchrony. Five methods for estimating phase differences between two signals, based on the phase angle of the Fourier Transform (PhD(FT)), paradoxical motion (PhD(PM)), the Lissajous figure (PhD(LF)), maximal linear correlation (PhD(P)) and least-squares filtering (PhD(LS)), were compared. Frequency-modulated signals, simulating compartmental chest wall volumes, were used to evaluate the methods. Breathing asynchrony was quantified in two ways; by estimating (a) a single PhD value for the entire recording and (b) time-varying PhDs, representing non-stationarities of human breathing. PhD(PM) and PhD(LF) had the lowest average errors (4%), and PhD(LS) had a slightly higher error. PhD(FT) had zero error when estimating a single PhD value but a considerable error when estimating time-varying PhDs. PhD(P) presented the highest errors in all cases. An application of this methodology is proposed in real compartmental chest wall volume signals of normal and COPD subjects. Preliminary results indicate that the methodology is promising in quantifying differences in asynchronous breathing between thoracic volumes of COPD patients and healthy controls.
Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Procesamiento de Señales Asistido por Computador , Pared Torácica/fisiopatología , Algoritmos , Ingeniería Biomédica , Estudios de Casos y Controles , Simulación por Computador , Ejercicio Físico , Análisis de Fourier , Humanos , Análisis de los Mínimos Cuadrados , Modelos Anatómicos , Monitoreo Ambulatorio/instrumentación , Monitoreo Ambulatorio/métodos , Enfermedad Pulmonar Obstructiva Crónica/patología , Reproducibilidad de los Resultados , Respiración , Pared Torácica/fisiologíaRESUMEN
We investigated whether the greater degree of exercise-induced diaphragmatic fatigue previously reported in highly trained athletes in hypoxia (compared with normoxia) could have a contribution from limited respiratory muscle blood flow. Seven trained cyclists completed three constant load 5 min exercise tests at inspired O(2) fractions (FIO2) of 0.13, 0.21 and 1.00 in balanced order. Work rates were selected to produce the same tidal volume, breathing frequency and respiratory muscle load at each FIO2 (63 +/- 1, 78 +/- 1 and 87 +/- 1% of normoxic maximal work rate, respectively). Intercostals and quadriceps muscle blood flow (IMBF and QMBF, respectively) were measured by near-infrared spectroscopy over the left 7th intercostal space and the left vastus lateralis muscle, respectively, using indocyanine green dye. The mean pressure time product of the diaphragm and the work of breathing did not differ across the three exercise tests. After hypoxic exercise, twitch transdiaphragmatic pressure fell by 33.3 +/- 4.8%, significantly (P < 0.05) more than after both normoxic (25.6 +/- 3.5% reduction) and hyperoxic (26.6 +/- 3.3% reduction) exercise, confirming greater fatigue in hypoxia. Despite lower leg power output in hypoxia, neither cardiac output nor QMBF (27.6 +/- 1.2 l min(-1) and 100.4 +/- 8.7 ml (100 ml)(-1) min(-1), respectively) were significantly different compared with normoxia (28.4 +/- 1.9 l min(-1) and 94.4 +/- 5.2 ml (100 ml)(-1) min(-1), respectively) and hyperoxia (27.8 +/- 1.6 l min(-1) and 95.1 +/- 7.8 ml (100 ml)(-1) min(-1), respectively). Neither IMBF was different across hypoxia, normoxia and hyperoxia (53.6 +/- 8.5, 49.9 +/- 5.9 and 52.9 +/- 5.9 ml (100 ml)(-1) min(-1), respectively). We conclude that when respiratory muscle energy requirement is not different between normoxia and hypoxia, diaphragmatic fatigue is greater in hypoxia as intercostal muscle blood flow is not increased (compared with normoxia) to compensate for the reduction in PaO2, thus further compromising O(2) supply to the respiratory muscles.
Asunto(s)
Ciclismo/fisiología , Diafragma/fisiología , Fatiga Muscular/fisiología , Músculos Respiratorios/irrigación sanguínea , Músculos Respiratorios/fisiología , Acidosis/fisiopatología , Adulto , Gasto Cardíaco , Prueba de Esfuerzo , Humanos , Hipoxia/fisiopatología , MasculinoRESUMEN
Measurement of respiratory muscle blood flow (RMBF) in humans has important implications for understanding patterns of blood flow distribution during exercise in healthy individuals and those with chronic disease. Previous studies examining RMBF in humans have required invasive methods on anesthetized subjects. To assess RMBF in awake subjects, we applied an indicator-dilution method using near-infrared spectroscopy (NIRS) and the light-absorbing tracer indocyanine green dye (ICG). NIRS optodes were placed on the left seventh intercostal space at the apposition of the costal diaphragm and on an inactive control muscle (vastus lateralis). The primary respiratory muscles within view of the NIRS optodes include the internal and external intercostals. Intravenous bolus injection of ICG allowed for cardiac output (by the conventional dye-dilution method with arterial sampling), RMBF, and vastus lateralis blood flow to be quantified simultaneously. Esophageal and gastric pressures were also measured to calculate the work of breathing and transdiaphragmatic pressure. Measurements were obtained in five conscious humans during both resting breathing and three separate 5-min bouts of constant isocapnic hyperpnea at 27.1 +/- 3.2, 56.0 +/- 6.1, and 75.9 +/- 5.7% of maximum minute ventilation as determined on a previous maximal exercise test. RMBF progressively increased (9.9 +/- 0.6, 14.8 +/- 2.7, 29.9 +/- 5.8, and 50.1 +/- 12.5 ml 100 ml(-1) min(-1), respectively) with increasing levels of ventilation while blood flow to the inactive control muscle remained constant (10.4 +/- 1.4, 8.7 +/- 0.7, 12.9 +/- 1.7, and 12.2 +/- 1.8 ml 100 ml(-1) min(-1), respectively). As ventilation rose, RMBF was closely and significantly correlated with 1) cardiac output (r = 0.994, P = 0.006), 2) the work of breathing (r = 0.995, P = 0.005), and 3) transdiaphragmatic pressure (r = 0.998, P = 0.002). These data suggest that the NIRS-ICG technique provides a feasible and sensitive index of RMBF at different levels of ventilation in humans.