[Respiratory telerehabilitation in cases of COPD]. / Mise au point sur la téléréadaptation respiratoire dans la BPCO.

Telerehabilitation brings together a set of rehabilitation practices applied remotely by means of information and communication technologies. Even though it has been taking on increasing importance in many health fields over 10 years, telerehabilitation had yet to find its place in pulmonary rehabilitation before 2020, when the pandemic situation impelled numerous teams to put it to work. Pilot studies on respiratory diseases, primarily COPD, along with recent data from randomized or non-randomized studies, have enhanced our understanding of "remote" practice. In this review of the literature, we will show that pulmonary telerehabilitation is feasible, safe and likely to yield short-term (and possibly longer term) effects generally similar to those achieved in the pulmonary rehabilitation programs of specialized centers, especially as regards some indicators of exercise tolerance, dyspnea or patient quality of life. However, the number of studies and patients included in these programs remains too limited in terms of modalities, duration, long-term effects, or adaptations in case of exacerbation to be the subject of recommendations. The potential of respiratory telerehabilitation justifies continuing clinical trials and experiments, which need to be coordinated with the interventions characterizing a conventional program.

[Pulmonary rehabilitation, a historical perspective from Hippocrates to tele-rehabilitation]. / La réadaptation respiratoire, une perspective historique: d'Hippocrate à la télé-réadaptation.

In ancient times Hippocrates described a disease, the 3rd phthisis, which seems to correspond to COPD and is mainly treated by walking, gradually increasing the number of steps until reaching 10,000 steps a day at the end of the initial period of treatment. The recent era began in the second half of the 20th century and ended in 2015, with an unusual Cochrane Library editorial in which it was stated that the accumulated evidence (statistically significant and clinically relevant improvements in clinical signs, tolerance to exercise, quality of life, days hospitalization…) on the effects of rehabilitation programs suffice to suspend research on the subject and to justify focus on new elements in the programs. It is essential, in fact, to establish uniform practical recommendations for the prescription of routine rehabilitation (number and duration of physical activity sessions, therapeutic education, re-training intensity…). In addition, studies should be carried out on new practices: community or home rehabilitation, long-term rehabilitation, tele-rehabilitation.

[Physical activity and pulmonary rehabilitation]. / Activités physiques et réadaptation respiratoire.

INTRODUCTION: Physical activity in daily life (PA) in patients with chronic respiratory disease is reduced. Inactivity is associated with an increased risk of hospitalisation and mortality. Even though pulmonary rehabilitation (PR) is associated with improved quality of life (fewer symptoms, greater exercise capacity…), its benefits with regard to PA remain unclear. STATE OF THE ART: For each patient, it is important during a respiratory rehabilitation (RR) programme to evaluate PA and its determinants. Only programs aimed at improved self-management and including educational therapy (ETP) have shown a short-term increase of PA following PR. Several studies have reported better long-term adherence when professionals help the patient to construct a personalised PA project, with regular follow-up and an array of activities (local facilities, urban walking…) chosen by the patient and adapted to the environment. PERSPECTIVES: The ongoing SARS-CoV2 pandemic has highlighted the importance of human interaction, even at a distance using information and communication technologies, as a means of sustaining patient motivation. Future controlled and randomized studies should focus on the long-term impact on PA of innovative strategies in patients with chronic respiratory diseases. Moreover, it would be interesting to quantify the socioeconomic impact as well as the sustainable health benefits of the different strategies outlined in this review. CONCLUSION: It is not possible to offer a single solution likely to maintain RR benefits over an extended lapse of time. However, follow-up with an ETP and/or regular and customized support during the post-training period facilitates the long-term adoption of active behavior.

DLNO/DLCO ratio evolution under targeted therapy in patients with pulmonary hypertension.

The ratio of the diffusing capacity of the lung for carbon monoxide (DLCO) and for nitric oxide (DLNO) measured simultaneously is modified in patients with precapillary pulmonary hypertension (PH). The potential impact of targeted therapy on the DLCO/DLNO ratio is unknown. Simultaneous measurements of DLNO and DLCO were performed at baseline, 3-4 month follow-up (first evaluation) and 12-month follow-up (second evaluation) after initiation of targeted PH therapies in incident cases of precapillary PH. The main outcome was the change in DLNO/DLCO ratio under treatment between baseline and the first evaluation. Twenty-nine patients were included (mean age: 66.8 years, 62.1% female). No significant change in the DLNO/DLCO ratio was found between baseline and the first evaluation. Similarly, no significant differences were noted with regard to changes in Dm or Vc, the DLNO/DLCO ratio in different patient subgroups, or in the 20 patients evaluated at the second follow-up. Within the limitations of this study, the DLNO/DLCO ratio is not useful in monitoring the response to treatment in PH.

[Guide for follow-up of patients with SARS-CoV-2 pneumonia. Management proposals developed by the French-language Respiratory Medicine Society. Version of 10 May 2020]. / Guide pour le suivi respiratoire des patients ayant présenté une pneumonie à SARS-CoV-2. Propositions de prise en charge élaborées par la Société de pneumologie de langue française. Version du 10 mai 2020.

The French-language Respiratory Medicine Society (SPLF) proposes a guide for the follow-up of patients who have presented with SARS-CoV-2 pneumonia. The proposals are based on known data from previous epidemics, on acute lesions observed in SARS-CoV-2 patients and on expert opinion. This guide proposes a follow-up based on three categories of patients: (1) patients managed outside hospital for possible or proven SARS-CoV-2 infection, referred by their physician for persistent dyspnoea; (2) patients hospitalized for SARS-CoV-2 pneumonia in a medical unit; (3) patients hospitalized for SARS-CoV-2 pneumonia in an intensive care unit. The subsequent follow-up will have to be adapted to the initial assessment. This guide emphasises the possibility of others causes of dyspnoea (cardiac, thromboembolic, hyperventilation syndrome…). These proposals may evolve over time as more knowledge becomes available.

Prevalence of sarcopenia and malnutrition during acute exacerbation of COPD and after 6 months recovery.

BACKGROUND/OBJECTIVES: Sarcopenia defined by the association of skeletal muscle mass depletion and a decreased physical performance is underdiagnosed in chronic obstructive pulmonary disease (COPD) patients. The objective was to assess prevalence of sarcopenia and malnutrition in hospitalized COPD patients during an acute exacerbation, after 6 months follow-up and the 1-year survival. SUBJECTS/METHODS: Hospitalized COPD patients were recruited for the assessment of body composition, handgrip strength, respiratory function, and maximal inspiratory and expiratory pressures (MIP and MEP), during hospitalization and 6 months later. Sarcopenia was defined according to the criteria of the European Working Group on Sarcopenia in Older Adults, malnutrition was defined according to French criteria 2007. Survival data were collected 12 months after hospitalization. RESULTS: We analyzed data from 54 patients, aged 68 ± 9 years and BMI 26.9 ± 7.8 kg/m2, with an average FEV1 of 1.13 ± 0.49 l (45 ± 16% predicted value). Sarcopenia and malnutrition prevalence were, respectively, 48% and 52% during hospitalization, 30% and 30% after 6 months. MIP and MEP were lower in sarcopenic patients (p = 0.01 and 0.009, respectively). In multivariate analysis, skeletal muscle mass index and MIP were positively correlated at 6 months' follow-up (r = 0.40, p = 0.04). The 1-year survival rate was lower in sarcopenic patients (65 vs 86%, p = 0.03), particularly when malnutrition was associated (p = 0.02). CONCLUSIONS: Sarcopenia in COPD patients is highly prevalent during and after recovery of an acute exacerbation, exposing to lower survival. A multimodal management is required to treat sarcopenia and improve prognosis.

[Chronic cough in the elderly is associated with expiratory flow limitation]. / La toux chronique du sujet âgé est associée à une limitation expiratoire des débits.

As chronic respiratory symptoms and the presence of expiratory flow limitation (EFL) are commonly reported in the elderly, we investigated whether they were associated in a population of 75 years old volunteers. We analyzed the results of a prevalence survey of chronic respiratory symptoms and respiratory infections, and performed spirometry and measured EFL after application of a negative expiratory pressure at the mouth (NEP). EFL was present in 170 (46%) subjects, a chronic cough in 49 (13%), chronic sputum in 58 (29%) and a history of respiratory infection in 62 (17%). Chronic cough and the composite outcome "chronic cough or sputum" were significantly associated with the presence of EFL (respectively 60% vs. 43%, OR=2.04 [1.09 to 3.78], P=0.023, and 56% vs. 43%, OR=1.74 [1.05 to 2.87], P=0.04), after controlling for smoking or airway obstruction. History of respiratory infections were not associated with an increased prevalence of EFL. We concluded that the presence of a LED could be an interesting indicator of respiratory aging. Its detection could be advocated in elderly subjects presenting with respiratory symptoms.

[Managements of chronic cough in general medicine and requirements of general practitioners]. / Prise en charge des toux chroniques difficiles en médecine générale et attente des médecins généralistes.

Chronic cough represents a persistent dilemma, for general practitioner (GP), inducing a lot of medical investigations. Few data are available about French GP practice and their expectancy from cough specialists. We studied management in primary care and impressions of GP of patients with chronic cough. Thirty-four patients were studied. They were mostly women, mean age was above 50 years-old, and the waste majority of patients were non-smokers. Halftime, the symptom was persistent (more than 6 months), had promoted numerous medical consultations (more than five). Drugs were prescribed since the first visit for the majority of patients, principally cough-sedation drugs, steroids and bronchodilatators. A chest radiography was realized in almost all patients. Advices were asked (with a decreasing frequency) to physicians specialized in: ear-nose-throat or respiratory, gastroenterology, allergy, or cardiology. The majority of patients were satisfied of their GP, despite persistent symptoms. From the point of the GP, chronic cough remains a relentless dilemma. Their main purpose, when they addressed their patient to a specialized physician, was to obtain an etiologic diagnosis. When they were asked "which tool will be more adequate for you in the next future?", the preferred response was "a simple etiologic algorithm". Despite persistent symptoms, inducing furthers medical consultations, the main ask from GP was to promote a simple etiologic algorithm.

[Non-invasive study of pulmonary vascular recruitment during exercise]. / Etude non invasive du recrutement vasculaire pulmonaire lors de l'exercice musculaire.

The in vivo study of the pulmonary microcirculation, and its recruitment, is currently not common, although it may be of interest. The intrabreath analysis (IB) of the carbon monoxide (CO) and acetylene (C(2)H(2)) diffusion is used to study the transfer of CO (TLCO) and the pulmonary capillary blood flow (Qs), particularly during exercise. The evolution of the Qs during different stages of exercise has never been reported in healthy subjects. The authors measured the Qs and TL at rest and then during and after short bouts of exercise in 12 healthy subjects. The Qs increased from 5.6 L/min at rest to 13.8 L/min during exercise while the TLCO increased from 11 to 16.7 mmol/kPa/min. A linear relationship was found between the Qs and the TLCO, with Qs values close to those obtained with other techniques. The Qs returned to rest values more rapidly than the TLCO (probably because of the membrane factor). Pulmonary vascular recruitment can be easily studied in healthy subjects. This parameter may be important in the study in pulmonary vascular diseases.

Is tidal expiratory flow limitation predictive of sleep-related disorders in the elderly?

Sleep-related disorders represent an important health burden and their prevalence increases with age. In patients with snoring or sleepiness, the presence of expiratory flow limitation (EFL), determined via the negative expiratory pressure (NEP) method, is related to the apnoea/hypopnoea index (AHI). In this study, we examined whether EFL can be used to predict obstructive sleep apnoea syndrome (OSAS) in healthy asymptomatic older subjects. A group of 72-yr-old subjects (n = 448, 44% males) with a mean body mass index of 25.5±3.8 kg·m(-2) were examined. All subjects underwent spirometry, NEP (-5 cmH(2)O, sitting position) and ventilatory polygraphy (VP). Spirometry was within normal values in 88% of the group and EFL was present in 143 (32%) subjects with a higher prevalence in females (89 out of 249 versus 54 out of 199 in females and males, respectively). VP showed an AHI<15 h(-1) in 238 subjects (53%) and OSAS with an AHI ≥15 h(-1) in 47%. EFL was found in 15% of subjects with OSAS. Consequently, EFL had low sensitivity and specificity in the prediction of OSAS (31.4% and 67.7%, respectively). We conclude that the prevalence of EFL is elevated in healthy older subjects and cannot be used to predict the presence of sleep-related disorders in an older population.

Performance and muscle oxygenation during isometric exercise and recovery in children with congenital heart diseases.

This study investigated performance, muscle oxygen saturation (StO2), and blood volume (BV) in patients with congenital heart diseases (CHD) and healthy children during and following sustained exercise. Maximal volunteered contraction (MVC) and endurance at 50 % of MVC (time to exhaustion, Tlim) of the knee extensor were measured in nine patients with CHD and 14 healthy control children. Near infrared spectroscopy was used to evaluated StO2 and BV in vastus lateralis. The drop in muscle oxygen saturation (D(mO2)), half time of recovery (T(SR)), and recovery speed to maximal oxygen saturation (Rs) were analyzed. Patients with CHD showed lower MVC (101.0 +/- 6.2 vs. 125.5 +/- 7.4 N x m, p < 0.01) and Tlim (67.0 +/- 7.5 vs. 127.5 +/- 11.1 s, p < 0.001) than control children. StO2 and BV values in both groups were similar at rest and decreased at the onset of contraction. D(mO2) was larger in patients, which reflected pronounced deoxygenation. During recovery, the patients exhibited a longer TSR (25.2 +/- 2.1 vs. 18.4 +/- 2.0 s, p < 0.05) and R(S) (64.6 +/- 5.5 vs. 42.7 +/- 4.6 s, p < 0.01) than control children. We concluded that reduced strength and endurance in patients with CHD were associated with an impairment of StO2 and BV, and a slower reoxygenation during recovery.

Effect of endurance training on muscle microvascular filtration capacity and vascular bed morphometry in the elderly.

AIM: Exercise training is a strong stimulus for vascular remodelling and could restore age-induced vascular alterations. The purpose of the study was to test the hypothesis that an increase in vascular bed filtration capacity would corroborate microvascular adaptation with training. METHODS: We quantified (1) microvascularization from vastus lateralis muscle biopsy to measure the capillary to fibre interface (LC/PF) and (2) the microvascular filtration capacity (K(f)) in lower limbs through a venous congestion plethysmography procedure. Twelve healthy older subjects (74 +/- 4 years) were submitted to a 14-week training programme during which lower-limbs were trained for endurance exercise. RESULTS: The training programme induced a significant increase in the aerobic exercise capacity of lower limbs (+11% V(O2peak); P < 0.05; +28% Citrate Synthase Activity; P < 0.01). K(f) was largely increased (4.3 +/- 0.9 10(-3) mL min(-1) mmHg(-1) 100 mL(-1) post-training vs. 2.4 +/- 0.8 pre-training, mean +/- SD; P < 0.05) and microvascularization developed as shown by the rise in LC/PF (0.29 +/- 0.06 post- vs. 0.23 +/- 0.06 pre-training; P < 0.05). Furthermore, K(f) and LC/PF were correlated (r = 0.65, P < 0.05). CONCLUSION: These results demonstrated the microvascular adaptation to endurance training in the elderly. The increase in K(f) with endurance training was probably related to a greater surface of exchange with an increased microvessel/fibre interface area. We conclude that measurement of the microvascular filtration rate reflects the change in the muscle exchange area and is influenced by exercise training.

[Dyspnea of effort associated with a congenital aortic malformation]. / Une dyspnée d'exercice associée à une malformation aortique congénitale.

INTRODUCTION: We report the case of a young woman presenting with dyspnoea of effort. Her records noted that correction of a double aortic arch had been performed in the neonatal period. At rest her flow/volume loop showed a moderate reduction of peak flow without an expiratory plateau. Exercise capacity was limited by sudden onset, during the last 2 stages of the test, of inspiratory dyspnea and tachypnea. During recovery there was no evidence of bronchospasm. CASE REPORT: With this picture we suspected upper airway obstruction and bronchoscopy revealed tracheal compression to 50% of normal. CT scan with 3 dimensional reconstruction showed the trachea compressed between 2 aortic branches. In order to confirm that the tracheal compression increased during exercise we induced sympathetic stimulation by a "handgrip" test that reproduced the inspiratory dyspnea and lead to a reduction in inspiratory flows. CONCLUSION: We have thus demonstrated that the increase in tracheal compression leading to limitation of airflow on exercise was due to an increase in aortic pressure and not to an increase in ventilatory flows.

Microdialysis of insulin-like growth factor-I in human muscle.

The determination of the insulin like growth factor I (IGF-I) concentration in the interstitial milieu is of outstanding importance to explore its autocrine/paracrine function. We previously reported a method to calibrate microdialysis probes for lactate and glucose (slope method). In the present study, we investigated the ability of our method to determine the concentration of larger molecules, such as IGF-I. We observed in vitro a close linear relationship (r = 0.86, P < 0.0005) between the recoveries of lactate (RecLac) and of IGF-I (RecIGF-I), giving access to the measurement of IGF-I with the same accuracy as the one previously found for lactate and glucose. In seven human volunteers, we calibrated each probe with the slope method: we first determined in vivo for every probe the specific RecLac/loss ethanol relationship and thereafter, using that relationship, we deduced RecLac from the loss ethanol value measured in every dialysate. This allowed calculation of RecIGF-I from the calculated RecLac value and the in vitro RecLac/RecIGF-I relationship, and finally free IGF-I concentration in muscle interstitial fluid. The mean free IGF-I interstitial concentration was 6.8 +/- 3.2 ng/ml while the mean plasma concentration was 0.4 +/- 0.2 ng/ml. This large gradient from interstitium to plasma for free IGF-I could be related to the local action of this growth factor.

Validation of a new calibration method for human muscle microdialysis at rest and during exercise.

Microdialysis presents the unique possibility to measure metabolite concentrations in human interstitial fluid. During exercise, the recovery of these metabolites should be precisely monitored since it is known to increase greatly with muscle blood flow. The loss of ethanol, perfused at low concentration, can be accurately measured and reflects the changes in dialysis conditions. We evaluated whether using the relationship determined in resting metabolic conditions between the loss of ethanol, as reference substance, and the recovery for lactate or glucose would allow us to calculate precisely the concentration of these substances and their variations during exercise. Using the new catheter calibration method (slope method), the error of estimation of lactate and glucose in vitro was limited to -0.6 (5.8)% and -0.7 (6.2)%, respectively. In resting human muscle, the slope method proved to be as accurate as an established calibration technique ("no net flux method") to evaluate interstitial lactate concentration [1.82 (0.58) vs 1.83 (0.47) mM, respectively]. During dynamic knee-extension exercise or light neuromuscular electrical stimulation, the estimated interstitial lactate and glucose concentrations varied differently, but their time course changes remained consistent with their respective plasma values. We conclude that, after an initial calibration step, the slope method allows accurate measurement of interstitial muscle metabolites and it could be used to monitor rapid metabolic changes during exercise.

Influence of exercise training on cardiac baroreflex sensitivity in patients with COPD.

Decreased spontaneous cardiac baroreflex sensitivity (BRS), which could lead to the onset of cardiovascular events, has been demonstrated in chronic obstructive pulmonary disease patients. This study evaluates the effects of an exercise training programme on BRS. Twenty-one chronic obstructive pulmonary disease patients (mean+/-SD age 62+/-9 yrs; forced expiratory volume in one second 43.6+/-18.1% of the predicted value) with mild hypoxaemia (arterial oxygen tension 8.96+/-1.18 kPa) were compared to 18 healthy age-matched subjects. BRS was calculated as the slope of the baroreflex sequences between spontaneous changes in systolic blood pressure and subsequent consecutive relative risk deviation length, and was measured in the supine position and following head-up tilt for sympathetic stimulation. Pulmonary function test results and blood gas levels, measured only in patients, did not change after the training programme. Exercise training increased the maximal sustained workload (16.5%) and peak oxygen consumption (20.5%). Before training, BRS was lower in patients than in controls (2.7+/-1.5 versus 7.8+/-4.9 ms x mmHg(-1)) and tilting induced a smaller reduction in BRS (13 versus 34%). After training, BRS increased to 3.4+/-2.6 ms x mmHg(-1) in patients but remained lower than in controls. The response to the tilt test remained unchanged after training. It is concluded that, in chronic obstructive pulmonary disease patients, exercise training is associated with a gain in spontaneous baroreflex sensitivity, reflecting cardiovascular benefits.

Enhancement of microvessel tortuosity in the vastus lateralis muscle of old men in response to endurance training.

Muscle microvascularization is usually quantified in transverse sections, in absolute terms (capillaries around fibres, CAF, or capillary-to-fibre ratio, C/F) or as CAF related to fibre area (CAF/area, CAFA). The capillary-to-fibre perimeter exchange ratio (CFPE) has been introduced in order to assess the role of the capillary-to-fibre interface in resistance to O(2) diffusion. The ratio between the length of capillaries in contact with fibres and fibre perimeter (LC/PF) has also been used as an index for capillary tortuosity. The possibility of change in capillary tortuosity with endurance training was not considered in previous studies. Consequently, this study investigated the effect of 14 weeks of endurance training on muscle microvascularization, including microvessel tortuosity, in 11 elderly men (8th decade). Microvessels were analysed using the CD31 antibody. Together with the significant increase in peak oxygen exchange and citrate synthase activity, there was a significant increase in C/F. While CFPE and CAFA remained unchanged, an important finding was the clear increase in LC/PF (56%; P < 0.001) for a same sarcomere length. We also found a strong correlation between oxidative enzyme activity and LC/PF both before and after training. These results indicate that endurance training induces significant remodelling in the microvessel network in elderly men and that an increase in the degree of microvessel tortuosity would be an important mechanism of adaptation to endurance training.