Relationships between heart rate target determined in different exercise testing in COPD patients to prescribed with individualized exercise training.

BACKGROUND: It has been scientifically proven that pulmonary rehabilitation improves exercise tolerance and facilitates the carrying out of daily physical activities. To optimize the physical and physiological benefits, it is necessary to individualize the training intensity for each patient. The aim of this study is to compare the heart rate (HR) responses to three exercise modalities measuring aerobic fitness in chronic obstructive pulmonary disease patients, in order to easily prescribe individual target HRs for endurance training. PATIENTS AND METHOD: Fifty COPD patients (mean age: 60.1±8.5 years) were included in the study. Each patient carried out a cardiopulmonary exercise test, a 6-minute walk test (6MWT) and a 6-minute stepper test (6MST). During these tests, HR was recorded continuously. After the cardiopulmonary exercise test, the HR was noted at the ventilatory threshold (VT) and at the end of the two exercise field tests (6MWTpeak and 6MSTpeak). The values of the HR during the last 3 minutes of both field tests were averaged (6MWT456 and 6MST456). Finally, the HR at 60% of the HR reserve was calculated with the values of the HR measured during 6MWT and 6MST (HRr60%walk, HRr60%step). RESULTS: The HRs measured during the 6MST were significantly higher than those measured during the 6MWT. The HRr60%step was not significantly different from 6MWT456 and 6MWTpeak HR (P=0.51; P=0.48). A significant correlation was observed between 6MWT456 and 6MWTpeak (r=0.58). The 6MWT456 and 6MWTpeak HR were correlated with HRr60%step (r=0.68 and r=0.62). The VT could be determined in 28 patients. The HRVT was not different from 6MWT456, 6MWTpeak, and HRr60%step (P=0.57, P=0.41 and P=0.88) and was correlated to 6MWT456, 6MWTpeak, and HRr60%step (r=0.45, r=0.40, r=0.48). CONCLUSION: An individualized target HR for endurance training can be prescribed from the HR measured during routine tests, such as 6MWT or 6MST.

Home-based neuromuscular electrical stimulation improves exercise tolerance and health-related quality of life in patients with COPD.

BACKGROUND: This retrospective, observational study of a routine clinical practice reports the feasibility and efficiency of home-based pulmonary rehabilitation (PR), including transcutaneous neuromuscular electrical stimulation (NMES) or usual endurance physical exercise (UEPE), on exercise tolerance, anxiety/depression, and health-related quality of life (HRQoL) in patients with COPD. METHODS: Seventy-one patients with COPD participated in home-based PR with NMES (Group NMES [GNMES]), while 117 patients participated in home-based PR with the UEPEs (Group UEPE [GUEPE]). NMES was applied for 30 minutes twice a day, every day. The endurance exercises in GUEPE began with a minimum 10-minute session at least 5 days a week, with the goal being 30-45 minutes per session. Three upper and lower limb muscle strengthening exercises lasting 10-15 minutes were also proposed to both the groups for daily practice. Moreover, PR in both the groups included a weekly 90-minute session based on an educational needs assessment. The sessions comprised endurance physical exercise for GUEPE, NMES for GNMES, resumption of physical daily living activities, therapeutic patient education, and psychosocial support to facilitate health behavior changes. Before and after PR, functional mobility and physical exercise capacity, anxiety, depression, and HRQoL were evaluated at home. RESULTS: The study revealed that NMES significantly improved functional mobility (-18.8% in GNMES and -20.6% in GUEPE), exercise capacity (+20.8% in GNMES and +21.8% in GUEPE), depression (-15.8% in GNMES and -30.1% in GUEPE), and overall HRQoL (-7.0% in GNMES and -18.5% in GUEPE) in the patients with COPD, regardless of the group (GNMES or GUEPE) or severity of airflow obstruction. Moreover, no significant difference was observed between the groups with respect to these data (P>0.05). CONCLUSION: Home-based PR including self-monitored NMES seems feasible and effective for severely disabled COPD patients with severe exercise intolerance.

Long-term evaluation of home-based pulmonary rehabilitation in patients with COPD.

INTRODUCTION: Personalized, global pulmonary rehabilitation (PR) management of patients with COPD is effective, regardless of the place in which this rehabilitation is provided. The objective of this retrospective observational study was to study the long-term outcome of exercise capacity and quality of life during management of patients with COPD treated by home-based PR. METHODS: Home-based PR was administered to 211 patients with COPD (mean age, 62.3±11.1 years; mean forced expiratory volume in 1 second, 41.5%±17.7%). Home-based PR was chosen because of the distance of the patient's home from the PR center and the patient's preference. Each patient was individually managed by a team member once a week for 8 weeks with unsupervised continuation of physical exercises on the other days of the week according to an individual action plan. Exercise conditioning, therapeutic patient education, and self-management were included in the PR program. The home assessment comprised evaluation of the patient's exercise capacity by a 6-minute stepper test, Timed Up and Go test, ten times sit-to-stand test, Hospital Anxiety and Depression score, and quality of life (Visual Simplified Respiratory Questionnaire, VQ11, Maugeri Respiratory Failure 28). RESULTS: No incidents or accidents were observed during the course of home-based PR. The 6-minute stepper test was significantly improved after completion of the program, at 6 months and 12 months, whereas the Timed Up and Go and ten times sit-to-stand test were improved after PR and at 6 months but not at 12 months. Hospital Anxiety and Depression and quality of life scores improved after PR, and this improvement persisted at 6 months and 12 months. CONCLUSION: Home-based PR for unselected patients with COPD is effective in the short term, and this effectiveness is maintained in the medium term (6 months) and long term (12 months). Home-based PR is an alternative to outpatient management provided all activities, such as exercise conditioning, therapeutic education, and self-management are performed.

Reproducibility and Sensitivity of the 6-Minute Stepper Test in Patients with COPD.

The aims of this study were to test the reproducibility of the 6-minute stepper test (6MST), and evaluate its accuracy in detecting improved functional capacity after pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD). Thirty-five COPD outpatients performed two 6MSTs in the same session, before (6MST1 and 6MST2) and after (6MST3 and 6MST4) PR. The performance, perceived exertion, heart rate and arterial oxygen saturation were measured during each 6MST. The performance was higher during the second 6MST of the same session (before PR: 514 strokes during the 6MST2 > 471 strokes during the 6MST1, and after PR: 559 strokes during the 6MST4 > 508 strokes during the 6MST3; p = 0.04). After PR, 6MST performance was higher than before PR (6MST3 > 6MST1 and 6MST4 > 6MST2; P < 0.01). The bias (the difference in the number of strokes) between the two 6MSTs from the same session (before PR: 6MST2-6MST1 = 42 strokes vs after PR: 6MST4-6MST3 = 52 strokes) was not different (P = 0.34). However, both bias were greater than 0 (P < 0.001). The mean performances for the two 6MSTs of the same session (before PR: 6MST1 and 6MST2 and after PR: 6MST3 and 6MST4) were correlated with the bias between these performances (P < 0.01; r = 0.32). The perceived exertions were lower after PR (P < 0.02). The systematic improvement of performance (8-10%) during the second 6MST of the each session may be explained from the warming of hydraulic jacks of the stepper and/or learning effect. On the other hand, the 6MST seems sufficiently sensitive to detect functional capacity improvements after PR in patients with COPD.

Prediction of peak oxygen uptake from ratings of perceived exertion during a sub-maximal cardiopulmonary exercise test in patients with chronic obstructive pulmonary disease.

PURPOSE: We assessed the validity of predicting peak oxygen uptake ([Formula: see text]O2 peak) from the relationship between oxygen uptake ([Formula: see text]O2) and overall ratings of perceived exertion (RPE) obtained during the initial stages of a cardiopulmonary exercise test (CPET). METHOD: Fifteen healthy participants and 18 patients with chronic obstructive pulmonary disease (COPD) performed a maximal CPET, during which [Formula: see text]O2 and RPE were measured until RPE15. RESULTS: Individual regressions between [Formula: see text]O2 and RPE ≤ 15 were extrapolated to RPE19 to predict [Formula: see text]O2 peak. Mean actual and predicted [Formula: see text]O2 peak were not significantly different in healthy women (18.9 ± 4.1 vs. 20.4 ± 4.5 mL kg(-1) min(-1), respectively) and men (28.9 ± 7.8 vs. 29.7 ± 8.5 mL kg(-1) min(-1), respectively), or in women (15.2 ± 4.7 vs. 15.8 ± 5.0 mL kg(-1) min(-1), respectively) and men (16.2 ± 4.4 vs. 17.4 ± 5.4 mL kg(-1) min(-1), respectively) with COPD (P = 0.067). Moreover, actual and predicted [Formula: see text]O2 peak were highly correlated in healthy participants and COPD patients (r ≥ 0.89; P < 0.001). The bias and 95 % limits of agreement were -1.0 ± 4.0 and -1.0 ± 4.6 mL kg(-1) min(-1) for healthy and COPD participants, respectively. CONCLUSION: [Formula: see text]O2 peak can be predicted with acceptable accuracy in healthy participants and patients with COPD from the individual relationship between [Formula: see text]O2 and RPE ≤ 15.

Hypersensitivity pneumonitis induced by Shiitake mushroom spores.

Hypersensitivity pneumonitis (HP) is a pulmonary granulomatosis involving an immunoallergic mechanism caused by chronic inhalation of antigens, most frequently organic substances, as well as chemicals. We report the first European case of hypersensitivity pneumonitis due to the inhalation of Shiitake mushroom spores. A 37-year-old French Caucasian man with a one-month history of persistent dry cough, shortness of breath and loss of weight was admitted to our hospital on December 2010. Anamnesis showed he was involved in mushroom production beginning in the summer of 2010. His temperature on admission was 36.6°C and he had a normal blood pressure (135/90 mmHg). Bilateral fine crackles were audible in the base of both lungs. Pulmonary function tests showed a mild restrictive pattern with decreased DLco and a PaO(2) of 65 mmHg, Chest CT scan revealed reticulo-nodular shadows, slight ground glass opacities, liner atelectasis, and subpleural opacities in both lung fields. Bronchoscopy was normal but cytological examination of BAL revealed a predominant lymphocytosis (55%). Serum precipitins to the Shiitake mushroom spores were positive (3 precipitins arcs with high intensity) and as a result we advised the patient to cease his mushroom production activities. The diagnosis of hypersensitivity pneumonitis due to inhalation of Shiitake mushroom spores was established as a result of the improvement of all of his clinical symptoms, i.e., cough, weight loss, bilateral fine crackles, mild restrictive pattern of pulmonary function, and reticulo-nodular shadows on chest CT, once exposure was eliminated. Recent interest in exotic mushrooms varieties, e.g., Shiitake, in developed countries because of their possible medicinal properties might increase the potential risk of HP among mushrooms workers. Therefore, healthcare professionals have to take this new potential respiratory disease into account.

An original field evaluation test for chronic obstructive pulmonary disease population: the six-minute stepper test.

PURPOSE: The aim of this study was to evaluate a new field test, the six-minute stepper test (6-MST), by studying its reproducibility, sensitivity and validity. METHODS: After a familiarization test, 16 patients with chronic obstructive pulmonary disease (COPD) and 15 healthy subjects performed two six-minute stepper tests per day over three evaluation days. Ten of the 16 patients with COPD also performed a six-minute walking test (6-MWT) with an analysis of gas exchange to compare the metabolic requirements of the two tests. Dyspnoea Borg values were evaluated with Borg's CR-10 scale. RESULTS: The mean (SD) scores for the COPD group for the first and second six-minute stepper tests were 382.49 (106.01) and 412.45 (118.39) strokes/6 minutes, respectively. Crossed comparison between the first or the second six-minute stepper tests of each evaluation day revealed no significant difference, indicating the reproducibility of the test. The sensitivity was demonstrated by a significantly higher performance in the healthy group (P < 0.001), demonstrating the ability of the test to detect two groups with different fitness levels. Finally, mean dyspnoea Borg values (SD) were significantly lower (P < 0.05) during the six-minute stepper test than during 6-MWT (2.5 (1.5) versus 3.1 (1.2)). CONCLUSIONS: This study demonstrated that the six-minute stepper test is a reproducible, sensitive, secure, well-tolerated and feasible test for patients with COPD. The reproducibility and sensitivity of the six-minute stepper test suggests that this test could be used in the evaluation of exercise tolerance in patients with COPD.

Breathing strategy in master athletes and untrained elderly subjects according to the incremental protocol.

To analyze the influence of step-duration protocol (1 vs. 3 min) on breathing strategy according to the physical fitness of healthy elderly subjects, this study compared the ventilatory responses and exercise tidal flow-volume loops (ETFVL) at the first and second ventilatory thresholds (VT(1) and VT(2)). Nineteen master athletes (mean age (+/- SD), 63.1 +/- 3.2 y; (.)VO(2)(max), 41.5 mL x (min x kg)(-1)) and 8 untrained elderly subjects (age, 65.5 +/- 2.3 y; (.)VO(2)(max), 25.8 mL x (min x kg)(-1)) performed 2 exhaustive exercise tests on a cycle ergometer. In untrained subjects, at VT(1) and VT(2), no significant difference was measured in ventilatory responses and ETFVL between protocols. Master athletes, at VT(2), presented a significantly higher (.)VCO(2) (P < 0.01), ventilation ((.)VE; P < 0.01), breathing frequency (f(b); P < 0.05), tidal volume relative to inspiratory capatcity (V(t)/IC) (P < 0.01),V(t) relative to forced vital capacity (V(t)/FVC; P < 0.05), and lower inspiratory reserve volume relative to FVC (IRV/FVC; P < 0.01) during the 1 min protocol than during the 3 min protocol. Master athletes, at maximal exercise, expressed significantly higher (.)VCO(2) (P < 0.01) and dyspnea (P < 0.05) with the shorter protocol. We concluded that, in untrained subjects, neither incremental exercise test had an impact on respiratory responses during exercise. Nevertheless, in master athletes, breathing strategy seems to be protocol dependent. The short test induced higher mechanical ventilatory constraints and dyspneic feeling than the long protocol, which could be explained by a higher (.)VE itself linked to a greater (.)VCO(2) and a higher blood lactate concentration.

Evidence of ventilatory constraints in healthy exercising prepubescent children.

We assessed expiratory airflow limitation (exp FL) in 18 healthy prepubescent children (6 girls and 12 boys, 10.1 +/- 0.3 years old), and examined how it might modulate regulation of tidal volume (V(T)) during exercise. The children performed a maximal incremental exercise on a cycle ergometer, preceded and followed by pulmonary function tests. Throughout exercise, breathing flow-volume loops were plotted into the maximal flow-volume loop (MFVL) measured at rest. End-expiratory and end-inspiratory lung volumes were estimated by measuring expiratory reserve volume relative to forced vital capacity (ERV/FVC), and inspiratory reserve volume relative to forced vital capacity (IRV/FVC), respectively. The exp FL, expressed as a percentage of V(T), was defined as the part of the tidal breath meeting the boundary of the MFVL. Ten children (FL) presented an exp FL at peak exercise (range, 16-78% of V(T)), and the remaining 8 constituted a non-flow-limited group (NFL). At peak exercise, FL presented a higher IRV/FVC and lower ERV/FVC (P < 0.01) than NFL children, demonstrating two different exercise breathing patterns. These results suggest that the NFL regulated V(T) at high lung volume, avoiding exp FL, while the FL breathed at low lung volume, leading to exp FL. At peak exercise, FL presented lower values of minute ventilation (P<0.05) and oxygen uptake (P<0.05) than NFL. Nevertheless, oxygen arterial saturation and dyspnea were similar in the two groups. In conclusion, ventilatory constraints may occur in healthy prepubescent children and result in relative dynamic hyperinflation or expiratory flow limitation.

Incremental exercise tests in master athletes and untrained older adults.

This study aimed to analyze the impact of step-duration protocols, 1-min vs. 3-min, on cardiorespiratory responses to exercise, whatever the aerobic-fitness level of sedentary (65.5 +/- 2.3 years, n = 8) or highly fit (63.1 +/- 3.2 years, n = 19) participants. Heart rate and VO2 at the first and second ventilatory thresholds (VT1 ,VT2) and maximal exercise were not significantly different between the two protocols. In master athletes, the 3-min protocol elicited significantly lower ventilation at VT2 and maximal exercise (p < .01). In the latter, breathlessness was also lower at maximal exercise (p < .05) than in sedentary participants. In trained or sedentary older adults, VT1, VT2, and were not influenced by stage duration. According to the lower breathlessness and ventilation, however, the 3-min step protocol could be more appropriate in master athletes. In untrained participants, because the cardiorespiratory responses were similar with the two incremental exercise tests, either of them could be used.

Exercise flow-volume loops in prepubescent aerobically trained children.

We studied mechanical ventilatory constraints in 13 aerobically trained (Tr) and 11 untrained (UT) prepubescent children by plotting the exercise flow-volume (F-V) loops within the maximal F-V loop (MFVL) measured at rest. The MFVL allowed to determine forced vital capacity (FVC) and maximal expiratory flows. Expiratory and inspiratory reserve volumes relative to FVC (ERV/FVC and IRV/FVC, respectively) were measured during a progressive exercise test until exhaustion. Breathing reserve (BR) and expiratory flow limitation (expFL), expressed in percentage of tidal volume (V(T)) and defined as the part of the tidal breath meeting the boundary of the MFVL, were measured. Higher FVC and maximal expiratory flows were found in Tr than UT (P < 0.05) at rest. Our results have shown that during exercise, excepting one subject, all Tr regulated their V(T) within FVC similarly during exercise, by breathing at low lung volume at the beginning of exercise followed breathing at high lung volume at strenuous exercise. In UT, ERV/FVC and IRV/FVC were regulated during exercise in many ways. The proportion of children who presented an expFL was nearly the same in both groups (approximately 70% with a range of 14 to 65% of V(T)), and no significant difference was found during exercise concerning expFL. However, higher ventilation (V(E)), ERV/FVC, and dyspnea associated with lower BR, IRV/FVC, and SaO2 were reported at peak power in Tr than UT (P < 0.05). These results suggest that, because of their higher Ve level, trained children presented higher ventilatory constraints than untrained. These may influence negatively the SaO2 level and dyspnea during strenuous exercise.

Ventilatory threshold characterizations during incremental rowing and cycling exercises in older subjects.

In order to individualize the intensity of an aerobic training program on different ergometers in healthy elderly subjects using a single test of muscular exercise, we analysed cardiorespiratory responses in 8 men (65.7 +/- 4.5 yrs) and 10 women (63.3 +/- 4.8 yrs). The heart rate corresponding to the ventilatory threshold was defined as individualised exercise intensity. All subjects carried out two incremental exercise tests on the cycle and rowing ergometers. For men, the results on the cycle ergometer and rowing ergometer demonstrated that, at ventilatory threshold, heart rates were not significantly different (114.6 +/- 13.7 and 115.6 +/- 14.2 beats x min (-1), respectively), but ventilation was significantly higher in rowing (p < 0.05). At ventilatory threshold, heart rates for women were not significantly different between the cycle ergometer and rowing ergometer (121.3 +/- 12.4 and 125.1 +/- 15.2 beats x min (-1 ), respectively), but ventilation was significantly higher in rowing (p< 0.01). At maximal exercise, maximal tidal volume for men (p < 0.01) and women (p < 0.05) was significantly higher in rowing. In spite of alterations of breathing patterns on the rowing ergometer, it is possible to design an individualized training program for healthy elderly subjects based on a single muscle evaluation exercise in order to diversify and optimize the cardiorespiratory benefits following an aerobic training program.

Evidence of exercise-induced arterial hypoxemia in prepubescent trained children.

Exercise-induced arterial hypoxemia (EIAH) is a recognized phenomenon in highly trained adults. Like adult athletes, prepubescent trained children may develop high-level metabolic demand but with a limited lung capacity in comparison with adults. The purpose of this investigation was to search for evidence of EIAH in prepubescent trained children. Twenty-four prepubescent (age: 10.3 +/- 0.2 y) trained children (10.0 +/- 0.7 h of weekly physical activity) performed pulmonary function tests and a graded maximal exercise test on a cycle ergometer. EIAH was defined as a drop of at least 4% from resting level arterial oxygen saturation (Sao(2)) measured by pulse oximetry. EIAH was observed in seven children. Forced vital capacity (FVC), ventilatory response to exercise (Delta(E)/Deltaco(2)), and breathing reserve at maximal exercise were significantly lower, whereas tidal volume relative to FVC was higher in hypoxemic children than in nonhypoxemic children; weekly physical activity and maximal oxygen uptake were similar. Moreover, positive relationships were found between Sao(2) at maximal exercise and breathing reserve (r = 0.56; p < 0.05) or volume relative to FVC (r = 0.70; p < 0.01). EIAH may occur in prepubescent trained children with a relatively low maximal oxygen uptake (42 mL. min(-1). kg(-1)); however, the mechanisms remain unclear and need to be investigated more accurately.