[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.

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.

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.

[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.

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.

[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.

Screening of obstructive sleep apnea syndrome by heart rate variability analysis.

BACKGROUND: Enhanced nocturnal heart rate variability (HRV) has been evoked in sleep-related breathing disorders. However, its capacity to detect obstructive sleep apnea syndrome (OSAS) has not been systematically determined. Thus, we evaluated the discriminant power of HRV parameters in a first group of patients (G1) and validated their discriminant capacity in a second group (G2). METHODS AND RESULTS: In G1, 39 of 91 patients (42.8%) were identified as diseased by polysomnography, as were 24 of 52 patients (46%) in G2. Time-domain HRV variables (SD of NN intervals [SDNN], mean of the standard deviations of all NN intervals for all consecutive 5-minute segments of the recording [SDNN index], square root of the mean of the sum of the squares of differences between adjacent normal RR intervals [r-MSSD], and SD of the averages of NN intervals in all 5-minute segments of the recording [SDANN]) were calculated for daytime and nighttime periods, as well as the differences between daytime and nighttime values (Delta[D/N]). Correlations between HRV variables and OSAS status were analyzed in G1 by use of receiver-operating characteristic (ROC) curves and logistic regression analysis. By ROC curve analysis, 7 variables were significantly associated with OSAS. After adjustment for other variables through multiple logistic regression analysis, Delta[D/N]SDNN index and Delta[D/N] r-MSSD remained significant independent predictors of OSAS, with ORs of 8.22 (95% CI, 3.16 to 21.4) and 2.86 (95% CI, 1.21 to 6.75), respectively. The classification and regression tree methodology demonstrated a sensitivity reaching 89.7% (95% CI, 73.7 to 97.7) with Delta[D/N] SDNN index and a specificity of 98.1% (95% CI, 86.4 to 100) with Delta[D/N] SDNN using appropriate thresholds. These thresholds, applied to G2, yielded a sensitivity of 83% using Delta[D/N] SDNN index and a specificity of 96.5% using Delta[D/N] SDNN. CONCLUSIONS: Time-domain HRV analysis may represent an accurate and inexpensive screening tool in clinically suspected OSAS patients and may help focus resources on those at the highest risk.

Accuracy of an automatic and patient-triggered long-term solid memory ambulatory cardiac event recorder.

This study evaluated the R-Test Evolution, a new type of cardiac event recorder bearing both patient-triggered and automatic capabilities. Its 7-day automatic arrhythmia analysis showed promising clinical advantages, especially when investigating patients with unexplained rare events such as syncope, feeling of weakness or faintness, palpitations, stroke, or in patients inconsistent in their use of patient-triggered recordings.

Efficacy and tolerance of a new silicone stent for the treatment of benign tracheal stenosis: preliminary results.

STUDY OBJECTIVE: In inoperable patients with tracheal stenosis who are treated using silicone stents, stent migration occurs in 18.6% of cases. To decrease the migration rate, we have designed a new silicone stent with narrow central and larger distal parts. This study analyzes the stability and tolerance of this new stent. DESIGN: Preliminary prospective study conducted in two French university hospitals. PATIENTS: Thirteen inoperable patients with benign complex tracheal stenosis due to intubation or tracheotomy. INTERVENTIONS: Tracheal stent insertion was performed under general anesthesia with a rigid bronchoscope. The patients were followed up clinically up to stent removal, which was planned at 18 months. RESULTS: Stent insertion or removal was very simple and did not differ from other silicone stents. No migration occurred after a mean follow-up of 22.8 months. Minimal granuloma formation occurred in only one patient (7.7%). Sputum retention remained similar to that with other silicone stents and could be improved by a smoother internal wall. Stents have been removed in seven patients after a mean duration of 19.6 months, with a complete stenosis cure in four cases. CONCLUSION: This new stent combines the excellent stability of the metallic stents and the tolerance and easy removal of straight silicone stents. This allows a prolonged use in order to obtain curative action.

Efficacy of tracheal and bronchial stent placement on respiratory functional tests.

Stent placement is the only available treatment in patients presenting either a localized external compression or a malacia of the tracheobronchial tree. To assess the functional benefit of prosthesis insertion in these indications, we compared functional respiratory values before, immediately after (48 h), and at sometime after (mean, 10.1 months) operation in 24 patients presenting with a bronchial lesion (B group, n = 5) or a lesion of the intrathoracic part (ITT group, n = 9) or of the extrathoracic part of the trachea (ETT group, n = 10). Before treatment, airflow was severely impaired in most patients without significant differences among the groups. After prosthesis insertion, airflow parameters increased [change in forced expiratory volume in 1 s (delta FEV1 = 440 mL; delta peak expiratory flow (PEF) = 0.92 L.s-1; delta maximum expiratory flow 25/75 (delta MEF25/75) = 0.47 L.s-1; and delta forced inspiratory volume in 1 s (delta FIV1 = 310 mL)] and airway resistances (Raws) decreased (delta Raw = -0.43 kPa.s-1.s-1) without any significant variation in either forced vital capacity (FVC) or total lung capacity. Airflow improvement was more apparent in ITT and ETT groups than in the B group. Moreover, inspiratory flow increase and decrease of FEV1/PEF ratio were only observed in the ETT group. This airflow improvement was maintained for a long time after and was associated with a good clinical tolerance. This study supports the clinical and functional benefits of prosthesis placement both in benign and malignant airway compressions for palliative treatment.

Comparison of muscle near-infrared spectroscopy and femoral blood gases during steady-state exercise in humans.

Near-infrared spectroscopy (NIRS) is a noninvasive way of measuring muscular oxygenation. We evaluated the relationship between NIRS signal [infrared muscle oxygen saturation (IR-SO2mus)] and the femoral venous oxygen saturation (SfvO2) during cycling exercise. Six healthy subjects performed a 30-min steady-state exercise at 80% maximal oxygen uptake in normoxia and hypoxia (inspired O2 fraction = 0.105). IR-So2mus was recorded continuously throughout the tests with the NIRS probe located on the vastus lateralis. During exercise, blood samples were withdrawn every 5 min from radial artery and femoral vein catheters. In normoxia, IR-So2mus initiated a transient nonsignificant decrease at 5 min, then returned to preexercise level, whereas SfvO2 showed a fast decrease, reaching 18% saturation at 10 min without further change. By contrast, in hypoxia, IR-SO2mus and SfvO2 demonstrated a parallel decrease then stabilized at 10 min. We conclude that IR-SO2mus appears to parallel SfvO2 when both the arterial and venous oxygen contents decrease during steady-state exercise in hypoxia, whereas IR-SO2mus does not follow SfvO2 change in normoxia.

Wavelet transform to quantify heart rate variability and to assess its instantaneous changes.

Heart rate variability is a recognized parameter for assessing autonomous nervous system activity. Fourier transform, the most commonly used method to analyze variability, does not offer an easy assessment of its dynamics because of limitations inherent in its stationary hypothesis. Conversely, wavelet transform allows analysis of nonstationary signals. We compared the respective yields of Fourier and wavelet transforms in analyzing heart rate variability during dynamic changes in autonomous nervous system balance induced by atropine and propranolol. Fourier and wavelet transforms were applied to sequences of heart rate intervals in six subjects receiving increasing doses of atropine and propranolol. At the lowest doses of atropine administered, heart rate variability increased, followed by a progressive decrease with higher doses. With the first dose of propranolol, there was a significant increase in heart rate variability, which progressively disappeared after the last dose. Wavelet transform gave significantly better quantitative analysis of heart rate variability than did Fourier transform during autonomous nervous system adaptations induced by both agents and provided novel temporally localized information.

Influence of training on NIRS muscle oxygen saturation during submaximal exercise.

PURPOSE: Endurance training improves the oxygen delivery and muscle metabolism. Muscle oxygen saturation measured by near infrared spectroscopy (IR-SO(2)), which is primarily influenced by the local delivery/demand balance, should thus be modified by training. We examined this effect by determining the influence of change in blood lactate and muscle capillary density with training on IR-SO(2) in seven healthy young subjects. METHODS: Two submaximal exercise tests at 50% (Ex1) and 80% pretraining VO(2max) (Ex2) were performed before and after a 4-wk endurance-training program. RESULTS: VO(2max) increased only slightly (+8%, NS) with training but the training effect was confirmed by the increased capillary density (+31%, P < 0.01) and citrate synthase activity (50%, P < 0.01), determined from muscle biopsy samples. Before training, blood lactate increased during the first 5 min of Ex1 and then remained constant (3.8 +/- 0.5 mmol x L(-1), P < 0.01), whereas it increased continuously during Ex2 (8.9 +/- 1.8 mmol x L(-1), P < 0.001). After training, lactate decreased significantly and remained constant during the two bouts of exercise (2.0 +/- 0.4 and 3.7 +/- 1.2 at the end of Ex1 and Ex2, respectively, both P < 0.001). During Ex1, IR-SO(2) dropped initially at the onset of exercise and recovered progressively without reaching the resting level. Training did not change this pattern of IR-SO(2). During Ex2, IR-SO(2) decreased progressively during the 15 min of exercise (P < 0.05); IR-SO2 kept constant after the initial drop after training. We found a significant relationship (r = 0.42, P = 0.03) between blood lactate and IR-SO(2) at the end of both bouts of exercise; this relationship was closer before training. By contrast, IR-SO(2) or IR-BV was not related to the capillary density. CONCLUSION: The training-induced adaptation in blood lactate influences IR-SO(2) during mild- to hard-intensity exercise. Thus, NIRS could be used as a noninvasive monitoring of training-induced adaptations.

Relation between heart rate variability and training load in middle-distance runners.

PURPOSE: Monitoring physical performance is of major importance in competitive sports. Indices commonly used, like resting heart rate, VO2max, and hormones, cannot be easily used because of difficulties in routine use, of variations too small to be reliable, or of technical challenges in acquiring the data. METHODS: We chose to assess autonomic nervous system activity using heart rate variability in seven middle-distance runners, aged 24.6 +/- 4.8 yr, during their usual training cycle composed of 3 wk of heavy training periods, followed by a relative resting week. The electrocardiogram was recorded overnight twice a week and temporal and frequency indices of heart rate variability, using Fourier and Wavelet transforms, were calculated. Daily training loads and fatigue sensations were estimated with a questionnaire. Similar recordings were performed in a sedentary control group. RESULTS: The results demonstrated a significant and progressive decrease in parasympathetic indices of up to -41% (P < 0.05) during the 3 wk of heavy training, followed by a significant increase during the relative resting week of up to +46% (P < 0.05). The indices of sympathetic activity followed the opposite trend, first up to +31% and then -24% (P < 0.05), respectively. The percentage increasing mean nocturnal heart rate variation remained below 12% (P < 0.05). There was no significant variation in the control group. CONCLUSION: This study confirmed that heavy training shifted the cardiac autonomic balance toward a predominance of the sympathetic over the parasympathetic drive. When recorded during the night, heart rate variability appeared to be a better tool than resting heart rate to evaluate cumulated physical fatigue, as it magnified the induced changes in autonomic nervous system activity. These results could be of interest for optimizing individual training profiles.

Age-associated alteration of muscle oxygenation measured by near infrared spectroscopy during exercise.

The influence of ageing on the capacity to increase muscle oxygen delivery during exercise is unclear. This was investigated by comparing the evolution of Near InfraRed Spectroscopy (NIRS) in 10 old (67 +/- 5 years, Old group) and 13 young subjects (27 +/- 4 years, Young group), during a progressive maximal exercise. The NIRS probe was placed on the vastus lateralis; muscle oxygen saturation - IR-SmO(2) - values were expressed on a scale using an arterial occlusion as the lower reference point and the subsequent reactive hyperaemia as the upper reference point. Resting IR-SmO( 2) was found to be significantly lower in the Old as co mpared to the Young group. During exercise, VO(2) increased similarly as a function of the workload whereas IR-SmO(2) decreased faster in old subjects than in young ones. Conversely, when expressed at the same percentage of VO( 2max), IR-SmO(2) followed a similar evolution in both groups from rest to maximal exercise (27.3 +/- 16.7 vs 24.3 +/- 12.9% decrease, in Old and Young group, respectively, NS). Thus, the initial difference remained constant between the two groups. During recovery, the time to recover the signal variation was not different between the two groups. We concluded that Old subjects demonstrate a systematic lower muscle oxygen saturation than Young ones. This difference could be explained by an age related decrease in muscle blood flow limiting O(2) supply.

[Study of chemosensitivity in patients believed to have sleep apnea syndrome]. / Etude de la chémosensibilité dans une population de patients suspects du syndrome d'apnées du sommeil.

We performed polysomnography and measured hypoxic ventilatory (HVR), hypercapnic ventilatory responses (HCVR) in 42 patients (60 +/- 11 years) with obesity and a clinical suspicion of sleep apnea syndrome (SAS) in order to determine whether an altered chemosensitivity was associated with SAS. The apnea/hypopnea index was 38 +/- 20 events per hour of sleep in 28 patients (SAS+ group) and less than 10 in the 14 others (SAS- group). The 2 groups differed only by a lower waking PaO2 in SAS+ as compared to SAS- (71.0 +/- 9 vs 77.4 +/- 8 mmHg, p < 0.05). HVR and HCVR were not significantly different in the 2 groups (0.82 +/- 0.58 vs 0.86 +/- 0.37 l.min-1.%-1; 1.41 +/- 0.81 vs 1.40 +/- 0.67 l.min-1.mmHg-1, respectively). In SAS+ group, HVR or HCVR did not change 3 or 12 months after continuous positive airway pressure (CPAP) therapy while both polysomnography and PaO2 returned to normal. We conclude that in patients with mild obesity and SAS there is no difference in chemosensitivity due to the presence of sleep apnea and that CPAP therapy does not alter these measurements. These results suggest no direct effect of SAS on chemosensitivity in the population studied.