27 research outputs found
Anatomy and physiology of the phrenic nerve and diaphragm in the perspective of diaphragm pacing in quadriplegic patients
The need to research refractory breathlessness
High-quality research is needed to improve quality of life for people with chronic refractory breathlessness in COP
Reduced Phrenic Motoneuron Recruitment during Sustained Inspiratory Threshold Loading Compared to Single-Breath Loading: A Twitch Interpolation Study
In humans, inspiratory constraints engage cortical networks involving the supplementary motor area. Functional magnetic resonance imaging (fMRI) shows that the spread and intensity of the corresponding respiratory-related cortical activation dramatically decrease when a discrete load becomes sustained. This has been interpreted as reflecting motor cortical reorganization and automatisation, but could proceed from sensory and/or affective habituation. To corroborate the existence of motor reorganization between single-breath and sustained inspiratory loading (namely changes in motor neurones recruitment), we conducted a diaphragm twitch interpolation study based on the hypothesis that motor reorganization should result in changes in the twitch interpolation slope. Fourteen healthy subjects (age: 21â40 years) were studied. Bilateral phrenic stimulation was delivered at rest, upon prepared and targeted voluntary inspiratory efforts (âvolâ), upon unprepared inspiratory efforts against a single-breath inspiratory threshold load (âsingle-breathâ), and upon sustained inspiratory efforts against the same type of load (âcontinuousâ). The slope of the relationship between diaphragm twitch transdiaphragmatic pressure and the underlying transdiaphragmatic pressure was â1.1 ± 0.2 during âvol,â â1.5 ± 0.7 during âsingle-breath,â and â0.6 ± 0.4 during âcontinuousâ (all slopes expressed in percent of baseline.percent of baselineâ1) all comparisons significant at the 5% level. The contribution of the diaphragm to inspiration, as assessed by the gastric pressure to transdiaphragmatic pressure ratio, was 31 ± 17% during âvol,â 22 ± 16% during âsingle-breathâ (p = 0.13), and 19 ± 9% during âcontinuousâ (p = 0.0015 vs. âvolâ). This study shows that the relationship between the amplitude of the transdiaphragmatic pressure produced by a diaphragm twitch and its counterpart produced by the underlying diaphragm contraction is not unequivocal. If twitch interpolation is interpreted as reflecting motoneuron recruitment, this study supports motor reorganization compatible with âdiaphragm sparingâ when an inspiratory threshold load becomes sustained
Investigation fonctionnelle respiratoire de la dyspnée chronique par le pneumologue
International audienceDyspnea results from an imbalance between ventilatory demand (linked to CO2 production, PaCO2 set-point and wasted ventilation-physiological dead space) and ventilatory capacity (linked to passive-compliance, resistance-and active-respiratory muscles-components of the respiratory system). Spirometry and static lung volumes investigate ventilatory capacity only. Ventilatory demand (increased for instance in all pulmonary vascular diseases due to increased physiological dead space) is not evaluated by these routine measurements. DLCO measurement, which evaluates both demand and capacity, depicts the best statistical correlation to dyspnea, for instance in obstructive and interstitial pulmonary diseases. Dyspnea has multiple domains and is inherently complex and weakly explained by resting investigations: explained variance is below 50%. The diagnostic strategy investigating dyspnea has to distinguish complaints related or not to exercise because dyspnea can occur independently from any effort. Cardiopulmonary exercise testing (V'O2, V'CO2, V'E and operating lung volumes measurements) allows the assessment of underlying pathophysiological mechanisms leading to functional impairment and can contribute to unmask potential underlying mechanisms of unexplained dyspnea although its "etiological diagnostic value" for dyspnea remains a challenging issue
Erratum to âPharmacological treatment optimization for stable chronic obstructive pulmonary disease. Proposals from the SociĂ©tĂ© de pneumologie de langue françaiseâ [Rev. Mal. Respir. 33 (2016) 911â936]
Nerf phrénique et diaphragme : considérations anatomiques et physiologiques dans la perspective de la stimulation phrénique implantée chez le blessé médullaire haut
Recommended from our members
âYou canât feel what we feelâ: Multifaceted dyspnea invisibility in advanced chronic obstructive pulmonary disease: A qualitative study
Inspiratory muscle training during pulmonary rehabilitation in chronic obstructive pulmonary disease: A randomized trial.
International audienceAlthough recommended by international guidelines, the benefit of inspiratory muscle training (IMT) in addition to rehabilitation remains uncertain. The objective was to demonstrate the effectiveness of IMT on dyspnea using Borg scale and multidimensional dyspnea profile questionnaire at the end of a 6-minute walk test (6MWT) in patients with chronic obstructive pulmonary disease (COPD) with preserved average maximum inspiratory pressure (PImax) of 85 cm H2O (95% of predicted (pred.) value) and admitted for a rehabilitation program in a dedicated center. In a randomized trial, comparing IMT versus no IMT in 32 COPD patients without inspiratory muscle weakness (PImax >60 cm H2O) who were admitted for pulmonary rehabilitation (PR) for 3 weeks, we evaluated the effect of IMT on dyspnea, using both Borg scale and multidimensional dyspnea profile (MDP) at the end of the 6MWT, and on functional parameters included inspiratory muscle function (PImax) and 6MWT. All testings were performed at the start and the end of PR. In unadjusted analysis, IMT was not found to be associated with an improvement of either dyspnea or PImax. After adjustment on confounders (initial Borg score) and variables of interaction (forced expiratory volume in 1 second (FEV1)), we found a trend toward an improvement of "dyspnea sensory intensity", items from MDP and a significant improvement on the variation in the 2 items of MDP ("tight or constricted" and "breathing a lot"). In the subgroup of patients with FEV1 50% pred. IMT did not significantly improve dyspnea or functional parameter in COPD patients with PImax > 60 cm H2O. However, in the subgroup of patients with FEV1 < 50% pred., MDP was significantly improved
Rev Mal Respir
The French-speaking Respiratory Medicine Society (SPLF) proposes a guide for the management of possible respiratory sequelae in patients who have presented with SARS-CoV-2Â pneumonia (COVID-19). The proposals are based on known data from previous epidemics, preliminary published data on post COVID-19Â follow-up and on expert opinion. The proposals were developed by a group of experts and then submitted, using the Delphi method, to a panel of 22Â pulmonologists. Seventeen proposals were validated ranging from additional examinations after the minimum assessment proposed in the SPLF monitoring guide, to inhaled or systemic corticosteroid therapy and antifibrotic agents. These proposals may evolve over time as knowledge accumulates. This guide emphasizes the importance of multidisciplinary discussion