Abords théorique et expérimental des capacités de transfert pulmonaire des monoxides de carbone et d'azote (applications à l'exercice, l'entrainement et au vieillissement)

POITIERS-BU Sciences (861942102) / SudocSudocFranceF

The validation of the sit-to-stand test for COPD patients

"Letter In response to Crook et al."International audienc

Does exercise have deleterious consequences for the lungs of patients with chronic heart failure?

International audienceChanges in lung function in patients with chronic heart failure (CHF), usually reported at rest, may be exacerbated during exercise and induce post-exercise effects. We investigated the hypothesis that post-exercise induced changes in lung function in CHF patients are due to the consequences of left atrial overload. Twenty-one CHF patients and six healthy subjects (Ctrl) participated in this study. Transfer lung capacity for carbon monoxide (T(LCO)) and maximal expiratory flows (V (max)) were measured before a maximal exercise test and 1h, 2h and 20h afterwards. CHF patients were divided in two groups according to their ventilatory response to the maximal exercise test (V(E) vs. V(CO(2)) relationship slopes above or below 34, i.e., CHF>34 and CHF34. T(LCO) per unit volume (K(CO)) was increased 1h post-exercise while maximal expiratory flow between 25 and 75% of forced vital capacity was decreased 2h and 20h post-exercise. We observed a negative correlation between the delta T(LCO) 1h post-exercise from rest and the delta T(LCO) 2h post-exercise from rest. The decreases in pulmonary V(max) we observed well after exercise following increases in K(CO) in patients with high ventilatory response to exercise (CHF>34) might indicate bronchial congestion resulting from increased left atrial pressure during exercise. We propose that endurance training should be prescribed cautiously for these patients

Does branched-chain amino acid supplementation improve pulmonary rehabilitation effect in COPD?

International audienceBackgroundMuscle wasting is frequent in chronic obstructive lung disease (COPD) and associated with low branched-chain amino acids (BCAA). We hypothesized that BCAA supplementation could potentiate the effect of a pulmonary rehabilitation program (PRP) by inducing muscular change.Materials and methodsSixty COPD patients (GOLD 2–3) were involved in an ambulatory 4-week PRP either with BCAA oral daily supplementation or placebo daily supplementation in a randomized double-blind design. Maximal exercise test including quadriceps oxygenation measurements, functional exercise test, muscle strength, lung function tests, body composition, dyspnea and quality of life were assessed before and after PRP.ResultsFifty-four patients (64.9 ± 8.3 years) completed the protocol. In both groups, maximal exercise capacity, functional and muscle performances, quality of life and dyspnea were improved after 4-week PRP (p ≤ 0.01). Changes in muscle oxygenation during the maximal exercise and recovery period were not modified after 4-week PRP in BCAA group. Contrarily, in the placebo group the muscle oxygenation kinetic of recovery was slowed down after PRP.ConclusionThis study demonstrated that a 4-week PRP with BCAA supplementation is not more beneficial than PRP alone for patients. A longer duration of supplementation or a more precise targeting of patients would need to be investigated to validate an effect on muscle recovery and to demonstrate other beneficial effects

Is the 1-minute sit-to-stand test a good tool for the evaluation of the impact of pulmonary rehabilitation? Determination of the minimal important difference in COPD

International audienceBackground: The 1-minute sit-to-stand (STS) test could be valuable to assess the level of exercise tolerance in chronic obstructive pulmonary disease (COPD). There is a need to provide the minimal important difference (MID) of this test in pulmonary rehabilitation (PR).Methods: COPD patients undergoing the 1-minute STS test before PR were included. The test was performed at baseline and the end of PR, as well as the 6-minute walk test, and the quadriceps maximum voluntary contraction (QMVC). Home and community-based programs were conducted as recommended. Responsiveness to PR was determined by the difference in the 1-minute STS test between baseline and the end of PR. The MID was evaluated using distribution and anchor-based methods.Results: Forty-eight COPD patients were included. At baseline, the significant predictors of the number of 1-minute STS repetitions were the 6-minute walk distance (6MWD) (r=0.574; P<10-3), age (r=-0.453; P=0.001), being on long-term oxygen treatment (r=-0.454; P=0.017), and the QMVC (r=0.424; P=0.031). The multivariate analysis explained 75.8% of the variance of 1-minute STS repetitions. The improvement of the 1-minute STS repetitions at the end of PR was 3.8±4.2 (P<10-3). It was mainly correlated with the change in QMVC (r=0.572; P=0.004) and 6MWD (r=0.428; P=0.006). Using the distribution-based analysis, an MID of 1.9 (standard error of measurement method) or 3.1 (standard deviation method) was found. With the 6MWD as anchor, the receiver operating characteristic curve identified the MID for the change in 1-minute STS repetitions at 2.5 (sensibility: 80%, specificity: 60%) with area under curve of 0.716.Conclusion: The 1-minute STS test is simple and sensitive to measure the efficiency of PR. An improvement of at least three repetitions is consistent with physical benefits after PR

Pulmonary diffusion variables in Andeans and Himalayans

info:eu-repo/semantics/nonPublishe

Physical activity evolution measured by actimeter in COPD patients after a pulmonary rehabilitation

Physical activity evolution measured by actimeter in COPD patients after a pulmonary rehabilitation. 28. International Congress of the European-Respiratory-Society (ERS

Pulmonary vascular reserve to predict exercise capacity at sea level and at high altitude

info:eu-repo/semantics/publishe

Pulmonary vascular reserve and exercise capacity at sea level and at high altitude.

It has been suggested that increased pulmonary vascular reserve, as defined by reduced pulmonary vascular resistance (PVR) and increased pulmonary transit of agitated contrast measured by echocardiography, might be associated with increased exercise capacity. Thus, at altitude, where PVR is increased because of hypoxic vasoconstriction, a reduced pulmonary vascular reserve could contribute to reduced exercise capacity. Furthermore, a lower PVR could be associated with higher capillary blood volume and an increased lung diffusing capacity. We reviewed echocardiographic estimates of PVR and measurements of lung diffusing capacity for nitric oxide (DL(NO)) and for carbon monoxide (DL(CO)) at rest, and incremental cardiopulmonary exercise tests in 64 healthy subjects at sea level and during 4 different medical expeditions at altitudes around 5000 m. Altitude exposure was associated with a decrease in maximum oxygen uptake (VO2max), from 42±10 to 32±8 mL/min/kg and increases in PVR, ventilatory equivalents for CO2 (V(E)/VCO2), DL(NO), and DL(CO). By univariate linear regression VO2max at sea level and at altitude was associated with V(E)/VCO2 (p<0.001), mean pulmonary artery pressure (mPpa, p<0.05), stroke volume index (SVI, p<0.05), DL(NO) (p<0.02), and DL(CO) (p=0.05). By multivariable analysis, VO2max at sea level and at altitude was associated with V(E)/VCO2, mPpa, SVI, and DL(NO). The multivariable analysis also showed that the altitude-related decrease in VO2max was associated with increased PVR and V(E)/VCO2. These results suggest that pulmonary vascular reserve, defined by a combination of decreased PVR and increased DL(NO), allows for superior aerobic exercise capacity at a lower ventilatory cost, at sea level and at high altitude.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Pulmonary Vascular Reserve and Exercise Capacity at Sea Level and at High Altitude

It has been suggested that increased pulmonary vascular reserve, as defined by reduced pulmonary vascular resistance (PVR) and increased pulmonary transit of agitated contrast measured by echocardiography, might be associated with increased exercise capacity. Thus, at altitude, where PVR is increased because of hypoxic vasoconstriction, a reduced pulmonary vascular reserve could contribute to reduced exercise capacity. Furthermore, a lower PVR could be associated with higher capillary blood volume and an increased lung diffusing capacity. We reviewed echocardiographic estimates of PVR and measurements of lung diffusing capacity for nitric oxide (DL(NO)) and for carbon monoxide (DL(CO)) at rest, and incremental cardiopulmonary exercise tests in 64 healthy subjects at sea level and during 4 different medical expeditions at altitudes around 5000 m. Altitude exposure was associated with a decrease in maximum oxygen uptake (VO2max), from 42±10 to 32±8 mL/min/kg and increases in PVR, ventilatory equivalents for CO2 (V(E)/VCO2), DL(NO), and DL(CO). By univariate linear regression VO2max at sea level and at altitude was associated with V(E)/VCO2 (p<0.001), mean pulmonary artery pressure (mPpa, p<0.05), stroke volume index (SVI, p<0.05), DL(NO) (p<0.02), and DL(CO) (p=0.05). By multivariable analysis, VO2max at sea level and at altitude was associated with V(E)/VCO2, mPpa, SVI, and DL(NO). The multivariable analysis also showed that the altitude-related decrease in VO2max was associated with increased PVR and V(E)/VCO2. These results suggest that pulmonary vascular reserve, defined by a combination of decreased PVR and increased DL(NO), allows for superior aerobic exercise capacity at a lower ventilatory cost, at sea level and at high altitude.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe