The evaluation of a 13-month maintenance program (MP) for 39 severe COPD patients with FEV(1)%pred 44(7)% who, as result of two different 8-week leg exercise training (LET) programs, one supervised ...at the hospital (group S; n = 20) and the other self-monitored (SM; n = 19), had achieved different levels of exercise tolerance. After LET, patients in group S had a higher maximal oxygen uptake and endurance time than patients in the SM group O(2)max 1.43(0.30) l. min(-1) vs l.25(0.27) l. min(-1) and endurance-time 16(4) min vs 12 (5) min, respectively). During the MP patients were advised to walk vigorously at least 4 km/day, 4 times/wk. After the MP, while endurance time remained higher than at baseline, it had decreased ( p < 0.01) immediately after LET in both groups and no differences were evident between groups (11(4) min and 10(4), respectively). In contrast, Chronic Respiratory Diseases Questionnaire scores, which had improved significantly after LET in both groups, remained high. Long-term effects of MP were independent of the training strategy or whether physiological improvements had been obtained with the initial LET. SM exercise programs do not seem capable of maintaining physiological improvements in exercise tolerance, though "quality of life" can be maintained.
El futuro de las pruebas de esfuerzo Puente Maestú, Luis; García de Pedro, Julia; Benedetti, Paola Antonella
Archivos de bronconeumología,
August 2018, Letnik:
54, Številka:
8
Journal Article
We undertook the present study to investigate the perception of dyspnea (with respect to changes in end-inspiratory and end-expiratory lung volumes), during four different levels of high-intensity ...constant work rate exercise (CWRE) in patients with severe COPD
Crossover descriptive study with consecutively recruited subjects
Tertiary university hospital
Twenty-seven subjects with severe COPD (mean ± SD age, 65 ± 5 years of age; mean FEV1, 43 ± 8% predicted; and mean inspiratory capacity IC; 74 ± 14% predicted)
Subjects randomly performed four high-intensity CWRE tests (conducted at 65%, 75%, 85%, and 95% of their symptom-limited peak work rate). Dyspnea, leg fatigue, and IC were determined every 2 min during exercise with breath-by-breath gas exchange and ventilatory measurements. There was a good correlation between the resting IC percent predicted and the oxygen uptake ( V.o2) peak (r= 0.64 to 0.69 between the IC percent predicted and V.o2peak at the four work rates). There were significant differences (p < 0.01) in mean respiratory rate (33 ± 6, 35 ± 6, 37 ± 6, and 38 ± 6 min), peak dyspnea score (5.9 ± 1.3, 6.3 ± 1.4, 6.8 ± 1.2, and 6.9 ± 1.6), minute ventilation (45.0 ± 8.7, 43.8 ± 7.7, 43.1 ± 8.7, and 42.8 ± 8.0 L/min), leg fatigue (4.8 ± 1.3, 5.1 ± 1.3, 5.7 ± 1.4, and 5.8 ± 1.4), and end-tidal carbon dioxide partial pressure (4.41 ± 0.36, 4.53 ± 0.33, 4.66 ± 0.31, and 4.76 ± 0.24 kPa), respectively, for tests conducted at 65%, 75%, 85%, and 95% of their symptom-limited peak work rate, and in mean end-expiratory lung volume (EELV 4.55 ± 0.44, 4.69 ± 0.43, and 4.79 ± 0.43 L), respectively, for tests conducted at 65%, 75%, and 85% of their symptom-limited peak work rate. In multivariable analysis, the factors that were independently correlated with dyspnea (p < 0.05) were EELV, peak inspiratory flow, and leg fatigue/discomfort
In COPD subjects with flow limitation at rest, the perception of dyspnea increased nonlinearly with the magnitude of high-intensity CWRE in association with a faster respiratory pattern and an increase in EELV. At the highest work rates, it appeared that a reduction in tidal volume and ventilation peak may have limited the tolerance to exercise
During physical exertion, the ventilatory response of patients with severe chronic obstructive pulmonary disease (COPD) is more rapid and shallow than that of healthy subjects. There is evidence that ...exercise training can alter breathing pattern in COPD patients. The purpose of the present study was to observe the effects of physical training on patients with severe COPD and to determine whether or not any possible changes were maintained over time.
Patients with severe COPD without bronchial reversibility were enrolled in a randomized controlled trial of a peripheral muscle training program carried out in a hospital setting. All enrolled patients were clinically stable, without exacerbation, and were randomly assigned to a training program of high (group A) or low (group B) intensity.
Thirty-five men with severe COPD in stable condition (mean SD forced expiratory volume in 1 second at 41%7%) were enrolled in the study. The mean age was 64(5) years. Group A underwent training at 70(22) W and group B at 35(10) W, such that the estimated total work was 8050(2882) kJ in group A and 4044(1205) kJ in group B. Breathing pattern changes were detected in exercise tests only for group A patients, but the changes were not maintained 12 months after the end of the program.
Intense training produces changes in the breathing pattern of patients with severe COPD. The changes are not specific to the task performed, not dependent on lactate production, and not maintained over the long term.
Durante el esfuerzo físico la respuesta ventilatoria de los enfermos con enfermedad pulmonar obstructiva crónica (EPOC) grave es más rápida y superficial que la de los sujetos sanos, y existen indicios de que el entrenamiento físico podría cambiar el patrón ventilatorio de estos pacientes. El propósito del presente estudio fue comprobar los efectos que el entrenamiento físico de los pacientes con EPOC grave tiene sobre el patrón ventilatorio, así como determinar o no el mantenimiento de los posibles cambios producidos en el tiempo.
Se realizó un estudio aleatorio y controlado con pacientes con EPOC grave sin reversibilidad bronquial. En estos pacientes se efectuó una intervención mediante entrenamiento físico. Los pacientes fueron remitidos al hospital para entrenamiento muscular periférico, todos ellos en situación clínica estable, sin exacerbación, y fueron asignados a dos programas diferentes de entrenamiento físico.
Se estudiaron 35 pacientes varones con EPOC grave, estables (volumen espiratorio forzado en el primer segundo del 41 ± 7%), con una edad media de 64 ± 5 años, divididos en dos grupos con diferente potencia media estimada de entrenamiento (grupo A: 70 ± 22 W; grupo B: 35 ± 10 W) y trabajo total desarrollado (grupo A: 8.050 ± 2.882 kJ; grupo B: 4.044 ± 1.205 kJ). Sólo se objetivaron cambios en el patrón ventilatorio durante el ejercicio realizado durante la prueba de esfuerzo en el grupo A, que no se mantuvieron a los 12 meses de finalizado el programa.
El entrenamiento intenso produce cambios en el patrón ventilatorio de los pacientes con EPOC grave que son inespecíficos de la tarea e independientes de la producción de lactato, y que no se mantienen a largo plazo.
We studied 21 patients with chronic obstructive pulmonary disease aged mean (SD) 63 (10) years, with a mean forced expiratory volume in 1 s of 40 (6)% and a peak oxygen uptake of 67 (11)% of ...predicted values. Patients trained for 6 weeks on a cycle ergometer at high work-rates (WR). Near-infrared spectroscopy was used to obtain the time-constant of the deoxygenation recovery signal (tauHbO(2)) during three constant WR exercise tests, one below and two above the lactic acidosis threshold (theta(L)). Glycolytic and oxidative enzymes and lactate concentrations were assessed in muscle biopsies. The tauHbO(2) decreased significantly in all three constant WR tests: -18 (24)s, -20 (23) s and -13 (22) s, respectively. Endurance time increased in the higher WR tests, by 5.7 (4.8) min and 3.6 (2.7) min, respectively. The activity of citrate-synthase (CS) and creatine-kinase changed significantly from 20 (10) to 30 (13) micro mol x min(-1) x g(-1)and from 3.825 (950) to 3.402 (526) micro mol x min(-1) x g(-1), respectively. Training also improved significantly the mean response time of the on-transient of oxygen uptake (tau'VO(2)) of the below-theta(L) test. We found significant correlations between changes in CS and changes in tauHbO(2), tau'VO(2) and endurance time. We conclude that leg training accelerates the speed of re-oxygenation of the vastus lateralis muscle after exercise. This improvement is correlated to changes in the oxidative enzymes.
