Voluntary activation of the human diaphragm in health and disease

1998 ◽  
Vol 85 (6) ◽  
pp. 2146-2158 ◽  
Author(s):  
Christer Sinderby ◽  
Jennifer Beck ◽  
Jadranka Spahija ◽  
Jan Weinberg ◽  
Alex Grassino
Keyword(s):  
Healthy Subjects ◽  
Total Lung Capacity ◽  
Voluntary Activation ◽  
Chronic Obstructive ◽  
Quiet Breathing ◽  
Obstructive Pulmonary Disease ◽  
Transdiaphragmatic Pressure ◽  
Lung Capacity ◽  
Copd Patients ◽  
Crural Diaphragm

Intersubject comparison of the crural diaphragm electromyogram, as measured by an esophageal electrode, requires a reliable means for normalizing the signal. The present study set out 1) to evaluate which voluntary respiratory maneuvers provide high and reproducible diaphragm electromyogram root-mean-square (RMS) values and 2) to determine the relative diaphragm activation and mechanical and ventilatory outputs during breathing at rest in healthy subjects ( n = 5), in patients with severe chronic obstructive pulmonary disease (COPD, n = 5), and in restrictive patients with prior polio infection (PPI, n = 6). In all groups, mean voluntary maximal RMS values were higher during inspiration to total lung capacity than during sniff inhalation through the nose ( P = 0.035, ANOVA). The RMS (percentage of voluntary maximal RMS) during quiet breathing was 8% in healthy subjects, 43% in COPD patients, and 45% in PPI patients. Despite the large difference in relative RMS ( P = 0.012), there were no differences in mean transdiaphragmatic pressure ( P= 0.977) and tidal volumes ( P = 0.426). We conclude that voluntary maximal RMS is reliably obtained during an inspiration to total lung capacity but a sniff inhalation could be a useful complementary maneuver. Severe COPD and PPI patients breathing at rest are characterized by increased diaphragm activation with no change in diaphragm pressure generation.

scholarly journals Maximal Voluntary Breath-Holding Tele-Inspiratory Test in Patients with Chronic Obstructive Pulmonary Disease

2021 ◽  
Vol 15 (3) ◽  
pp. 155798832110158
Author(s):  
Abir Hedhli ◽  
Azza Slim ◽  
Yassine Ouahchi ◽  
Meriem Mjid ◽  
Jamel Koumenji ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Function ◽  
Pulmonary Disease ◽  
Total Lung Capacity ◽  
Breath Holding ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Lung Capacity ◽  
Copd Patients ◽  
The Mean

Maximal voluntary inspiratory breath-holding time (MVIBHT) has proved to be of clinical utility in some obstructive ventilatory defects. This study aims to correlate the breath-holding time with pulmonary function tests in patients with chronic obstructive pulmonary disease (COPD) and to determine the feasibility of using a breath-holding test in assessing the severity of COPD. A cross-sectional study including male patients with stable COPD were conducted. Patients with respiratory comorbidities and severe or unstable cardiac diseases were excluded. Patients were interviewed and examined. Six-minute walk test (6MWT) and plethysmography were performed.For MVIBHT collection, the subject was asked to inspire deeply and to hold the breath as long as possible at the maximum inspiratory level. This maneuver was repeated three times. The best value was used for further analysis. A total of 79 patients (mean age: 64.2 ± 8) were included in this study. The mean value of MVIBHT was 24.2 ± 8.5 s. We identified a positive and significant correlations between MVIBHT and forced vital capacity ( r = .630; p < .001) as well as MVIBHT and forced expiratory volume in 1 s (FEV1%) ( r = .671; p < .001). A significant inverse correlation with total lung capacity ( r = −.328; p = .019) and residual volume to total lung capacity ratio ( r = −.607; p < .001) was noted. MVIBHT was significantly correlated to the distance in the 6MWT ( r = .494; p < .001). The mean MVIBHT was significantly different within spirometric grades ( p < .001) and GOLD groups ( p = .002). At 20.5 s, MVIBHT had a sensitivity of 72% and specificity of 96% in determining COPD patients with FEV1 <50%. Our results provide additional evidence of the usefulness of MVIBHT in COPD patients as a pulmonary function parameter.

scholarly journals Awakening efficacy of a vibrotactile device in patients on home nocturnal ventilatory assistance and healthy subjects as family caregiver proxies

2020 ◽  
Vol 17 ◽  
pp. 147997312098333
Author(s):  
Valerie Attali ◽  
Sophie Lavault ◽  
Antoine Guerder ◽  
Saba Al-Youssef ◽  
Benjamin Dudoignon ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Vibrotactile Stimulus ◽  
Chronic Obstructive ◽  
Vibrotactile Stimulation ◽  
Obstructive Pulmonary Disease ◽  
Copd Patients ◽  
Random Intervals ◽  
Healthy Family ◽  
Central Hypoventilation ◽  
Hypoventilation Syndrome

The objective of this study was to test the capacity of vibrotactile stimulation transmitted to the wrist bones by a vibrating wristband to awaken healthy individuals and patients requiring home mechanical ventilation during sleep. Healthy subjects (n = 20) and patients with central hypoventilation (CH) (Congenital Central Hypoventilation syndrome n = 7; non-genetic form of CH n = 1) or chronic obstructive pulmonary disease (COPD) (n = 9), underwent a full-night polysomnography while wearing the wristband. Vibrotactile alarms were triggered five times during the night at random intervals. Electroencephalographic (EEG), clinical (trunk lift) and cognitive (record the time on a sheet of paper) arousals were recorded. Cognitive arousals were observed for 94% of the alarms in the healthy group and for 66% and 63% of subjects in the CH and COPD groups, respectively (p < 0.01). The percentage of participants experiencing cognitive arousals for all alarms, was 72% for healthy subjects, 37.5% for CH patients and 33% for COPD patients (ns) (94%, 50% and 44% for clinical arousals (p < 0.01) and 100%, 63% and 44% for EEG arousals (p < 0.01)). Device acceptance was good in the majority of cases, with the exception of one CH patient and eight healthy participants. In summary this study shows that a vibrotactile stimulus is effective to induce awakenings in healthy subjects, but is less effective in patients, supporting the notion that a vibrotactile stimulus could be an effective backup to a home mechanical ventilator audio alarm for healthy family caregivers.

scholarly journals DNAH5 is associated with total lung capacity in chronic obstructive pulmonary disease

2014 ◽  
Vol 15 (1) ◽  
Author(s):  
Jin Hwa Lee ◽  
Merry-Lynn N McDonald ◽  
Michael H Cho ◽  
Emily S Wan ◽  
Peter J Castaldi ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Total Lung Capacity ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Lung Capacity

Force reserve of the diaphragm in patients with chronic obstructive pulmonary disease

1983 ◽  
Vol 55 (1) ◽  
pp. 8-15 ◽  
Author(s):  
F. Bellemare ◽  
A. Grassino
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Normal Subjects ◽  
Chronic Obstructive ◽  
Cycle Duration ◽  
Inspiratory Time ◽  
Obstructive Pulmonary Disease ◽  
Transdiaphragmatic Pressure ◽  
Copd Patients ◽  
Gastric Pressure

The fatigue threshold of the human diaphragm in normal subjects corresponds to a transdiaphragmatic pressure (Pdi)-inspiratory time integral (TTdi) of about 15% of Pdimax. The TTdi of resting ventilation was measured in 20 patients with chronic obstructive pulmonary disease (COPD) and ranged between 1 and 12% of Pdimax (mean 5%). TTdi was significantly related to total airway resistance (Raw) (r = 0.57; P less than 0.05). Five of these patients were asked to voluntarily modify their TI/TT (ratio of inspiratory time to total cycle duration; from 0.33 to 0.49) so as to increase their TTdi from a control value of 8% to an imposed value of 17% of Pdimax. The imposed pattern induced a progressive decline in the high-frequency (150-350 Hz)/low-frequency (20-40 Hz) power ratio (H/L) of the diaphragm electromyogram (fatigue pattern), quantitatively similar to that seen in normal subjects breathing with similar TTdi levels. The decay in H/L was followed by a progressive fall in mean Pdi meanly due to decrease in gastric pressure swings. It is concluded that 1) the force reserve of the diaphragm in COPD patients is decreased because of a decrease in Pdimax; 2) the remaining force reserve of the diaphragm can be exhausted by even minor modifications in the breathing pattern; and 3) at a TI/TT of 0.40 our COPD patients can increase their mean Pdi 3-fold before reaching a fatiguing pattern of breathing compared with 8-fold in normal subjects.

Myosin heavy chain gene expression changes in the diaphragm of patients with chronic lung hyperinflation

1998 ◽  
Vol 274 (4) ◽  
pp. L527-L534 ◽  
Author(s):  
Jean-Jacques Mercadier ◽  
Ketty Schwartz ◽  
Stefano Schiaffino ◽  
Claudine Wisnewsky ◽  
Simonetta Ausoni ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Total Lung Capacity ◽  
Chronic Obstructive ◽  
Myosin Isoforms ◽  
Obstructive Pulmonary Disease ◽  
Lung Capacity ◽  
Fast Myosin ◽  
Residual Capacity

In striated muscle, chronic increases in workload result in changes in myosin phenotype. The aim of this study was to determine whether such changes occur in the diaphragm of patients with severe chronic obstructive pulmonary disease, a situation characterized by a chronic increase in respiratory load and lung volume. Diaphragm biopsies were obtained from 22 patients who underwent thoracic surgery. Myosin was characterized with electrophoresis in nondenaturing conditions, SDS-glycerol PAGE, and Western blotting with monoclonal antibodies specific for slow and fast myosin heavy chain (MHC) isoforms. Flow volume curves, total lung capacity, and functional residual capacity were measured before surgery in 20 patients. We found that the human diaphragm is composed of at least four myosin isoforms, one slow and three fast, resulting from the combination of three MHC species. Chronic overload was associated with an increase in the slow β-MHC species at the expense of the fast species (β-MHC, 78.2 ± 4.6 and 50.0 ± 6.5% in emphysematous and control patients, respectively; P < 0.005). Linear correlations were found between β-MHC percentage and forced expiratory volume in 1 s ( r = −0.52; P < 0.02), total lung capacity ( r = 0.44; P < 0.05), and functional residual capacity ( r = 0.65; P < 0.003). The human adult diaphragm is composed of a balanced proportion of slow and fast myosin isoforms. In patients with chronic obstructive pulmonary disease, the proportion of fast myosins decreases, whereas that of slow myosin increases. This increase appears to be closely related to lung hyperinflation and may reflect an adaptation of the diaphragm to the new functional requirements.

Crural diaphragm activation during dynamic contractions at various inspiratory flow rates

1998 ◽  
Vol 85 (2) ◽  
pp. 451-458 ◽  
Author(s):  
Jennifer Beck ◽  
Christer Sinderby ◽  
Lars Lindström ◽  
Alex Grassino
Keyword(s):  
Chest Wall ◽  
Functional Residual Capacity ◽  
Healthy Subjects ◽  
Total Lung Capacity ◽  
Inspiratory Flow ◽  
Transdiaphragmatic Pressure ◽  
Flow Rates ◽  
Lung Capacity ◽  
Dynamic Contractions ◽  
Residual Capacity

The purpose of this study was to evaluate the influence of velocity of shortening on the relationship between diaphragm activation and pressure generation in humans. This was achieved by relating the root mean square (RMS) of the diaphragm electromyogram to the transdiaphragmatic pressure (Pdi) generated during dynamic contractions at different inspiratory flow rates. Five healthy subjects inspired from functional residual capacity to total lung capacity at different flow rates while reproducing identical Pdi and chest wall configuration profiles. To change the inspiratory flow rate, subjects performed the inspirations while breathing across two different inspiratory resistances (10 and 100 cmH2O ⋅ l−1 ⋅ s), at mouth pressure targets of −10, −20, −40, and −60 cmH2O. The diaphragm electromyogram was recorded and analyzed with control of signal contamination and electrode positioning. RMS values obtained for inspirations with identical Pdi and chest wall configuration profiles were compared at the same percentage of inspiratory duration. At inspiratory flows ranging between 0.1 and 1.4 l/s, there was no difference in the RMS for the inspirations from functional residual capacity to total lung capacity when Pdi and chest wall configuration profiles were reproduced ( n = 4). At higher inspiratory flow rates, subjects were not able to reproduce their chest wall displacements and adopted different recruitment patterns. In conclusion, there was no evidence for increased demand of diaphragm activation when healthy subjects breathe with similar chest wall configuration and Pdi profiles, at increasing flow rates up to 1.4 l/s.

Heart rate recovery is associated with ventilatory constraints and excess ventilation during exercise in patients with chronic obstructive pulmonary disease

2018 ◽  
Vol 25 (15) ◽  
pp. 1667-1674 ◽  
Author(s):  
Ernesto Crisafulli ◽  
Matteo Vigna ◽  
Antonella Ielpo ◽  
Panagiota Tzani ◽  
Angelo Mangia ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Heart Rate ◽  
Pulmonary Disease ◽  
Total Lung Capacity ◽  
Heart Rate Recovery ◽  
Chronic Obstructive ◽  
Dynamic Hyperinflation ◽  
Inspiratory Capacity ◽  
Obstructive Pulmonary Disease ◽  
Lung Capacity

Background Heart rate recovery delay is a marker of cardiac autonomic dysfunction. In chronic obstructive pulmonary disease patients, the ventilatory response to exercise during incremental cardiopulmonary exercise test may add information about dynamic hyperinflation by low values of inspiratory capacity/total lung capacity ratio (at peak) and excess ventilation by the slope of minute ventilation to carbon dioxide output ratio (VE/VCO2 slope). We aimed to assess if the ventilatory response to exercise might be a determinant for heart rate recovery delay. Design An observational, prospective study. Methods Anthropometric characteristics, lung function and cardiopulmonary exercise test data were recorded in chronic obstructive pulmonary disease outpatients. A cut-off of heart rate recovery of 12 or more beats was used to define heart rate recovery delay. Results Of 254 patients enrolled, 156 (61%) showed heart rate recovery delay. As compared to patients with normal heart rate recovery, patients with delay were older, with a worse lung function and with lower values of peak oxygen uptake, maximal workload, oxygen pulse at rest and at peak, and inspiratory capacity/total lung capacity at peak. Conversely, VE/VCO2 slope and dyspnoea and leg fatigue perception at peak were higher in patients with heart rate recovery delay. In the multivariate regression model adjusted for age, sex, fat-free mass, heart rate at rest and use of β-blockers, we found that inspiratory capacity/total lung capacity at peak (<0.25) (odds ratio 2.61; P = 0.007) and VE/VCO2 slope (>32) (odds ratio 2.26; P = 0.018) predict the risk of heart rate recovery delay. Conclusions In chronic obstructive pulmonary disease outpatients, heart rate recovery is associated with dynamic hyperinflation and excess ventilation during exercise.

scholarly journals Obesity modulates diaphragm curvature in subjects with and without COPD

2017 ◽  
Vol 313 (5) ◽  
pp. R620-R629 ◽  
Author(s):  
Aladin M. Boriek ◽  
Michael A. Lopez ◽  
Cristina Velasco ◽  
Azam A. Bakir ◽  
Anna Frolov ◽  
...  
Keyword(s):  
Forced Expiratory Volume ◽  
Normal Weight ◽  
The Body ◽  
Diaphragm Muscle ◽  
Chronic Obstructive ◽  
Quiet Breathing ◽  
Obstructive Pulmonary Disease ◽  
Copd Patients ◽  
Left Hemidiaphragm ◽  
Residual Capacity

Obesity is a common comorbidity of chronic obstructive pulmonary disease (COPD) and has been associated with worse outcomes. However, it is unknown whether the interaction between obesity and COPD modulates diaphragm shape and consequently its function. The body mass index (BMI) has been used as a correlate of obesity. We tested the hypothesis that the shape of the diaphragm muscle and size of the ring of its insertion in non-COPD and COPD subjects are modulated by BMI. We recruited 48 COPD patients with postbronchiodilator forced expiratory volume in 1 s (FEV1)-to-forced vital capacity (FVC) < 0.7 and 29 age-matched smoker/exsmoker control (non-COPD) subjects, who underwent chest computed tomography (CT) at lung volumes ranging from functional residual capacity (FRC) to total lung capacity (TLC). We then computed maximum principal diaphragm curvature in the midcostal region of the left hemidiaphragm at the end of inspiration during quiet breathing (EI) and at TLC. The radius of maximum curvature of diaphragm muscle increased with BMI in both COPD and non-COPD subjects. The size of diaphragm ring of insertion on the chest wall also increased significantly with increasing BMI. Surprisingly, COPD severity did not appear to cause significant alteration in diaphragm shape except in normal-weight subjects at TLC. Our data uncovered important factors such as BMI, the size of the diaphragm ring of insertion, and disease severity that modulate the structure of the ventilatory pump in non-COPD and COPD subjects.

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