Lung and chest wall mechanics in mechanically ventilated COPD patients

1993 ◽  
Vol 74 (4) ◽  
pp. 1570-1580 ◽  
Author(s):  
C. Guerin ◽  
M. L. Coussa ◽  
N. T. Eissa ◽  
C. Corbeil ◽  
M. Chasse ◽  
...  
Keyword(s):  
Chest Wall ◽  
Time Constant ◽  
Viscoelastic Behavior ◽  
Normal Subjects ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Mechanically Ventilated ◽  
Airway Occlusion ◽  
Chest Wall Mechanics ◽  
Copd Patients

By use of the technique of rapid airway occlusion, the effects of inspiratory flow, volume, and time on lung and chest wall mechanics were investigated in 10 chronic obstructive pulmonary disease (COPD) patients mechanically ventilated for acute respiratory failure. We measured the interrupter resistance (Rint), which in humans reflects airway resistance; the additional resistances due to time constant inequality and viscoelastic pressure dissipations within the lungs (delta RL) and the chest wall; and the static and dynamic elastances of lung and chest wall. We observed that 1) static elastances of lung and chest wall in COPD patients were similar to those of normal subjects; 2) Rint of the lung was markedly increased and flow dependent in COPD patients, whereas Rint of the chest wall was negligible as in normal subjects; and 3) in COPD patients, delta RL was markedly increased at all inflation flows and volumes, reflecting increased time constant inequalities within the lungs and/or altered viscoelastic behavior. The results imply increased dynamic work due to Rint and delta RL and marked time dependency of pulmonary resistance and elastance in COPD patients.

Partitioning of work of breathing in mechanically ventilated COPD patients

1993 ◽  
Vol 75 (4) ◽  
pp. 1711-1719 ◽  
Author(s):  
M. L. Coussa ◽  
C. Guerin ◽  
N. T. Eissa ◽  
C. Corbeil ◽  
M. Chasse ◽  
...  
Keyword(s):  
Work Of Breathing ◽  
Normal Subjects ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Mechanically Ventilated ◽  
Airway Occlusion ◽  
Copd Patients ◽  
Additional Resistance ◽  
Work Done ◽  
Inspiratory Muscle Fatigue

In 10 sedated paralyzed mechanically ventilated chronic obstructive pulmonary disease (COPD) patients, we measured the inspiratory mechanical work done per breath on the respiratory system (WI,rs). We measured the tracheal and esophageal pressures to assess the lung (L) and chest wall (W) components of WI and used the technique of rapid airway occlusion during constant-flow inflation to partition WI into static work [Wst, including work due to intrinsic positive end-expiratory pressure (WPEEPi)], dynamic work due to airway resistance, and the additional resistance offered by the respiratory tissues. Although the patients were hyperinflated, the slope of the static volume-pressure relationships of the lung did not decrease with inflation volume up to 0.8 liter. WI,W was similar in COPD patients and normal subjects. All components of WI,L were higher in COPD patients. The increase in Wst,rs was due entirely to WPEEPi. Our data suggest that, during spontaneous breathing, COPD patients would probably develop inspiratory muscle fatigue, unless continuous positive airway pressure were applied to reduce WPEEPi.

Frequency characteristics of airway and tissue impedances in respiratory diseases

1991 ◽  
Vol 71 (1) ◽  
pp. 259-270 ◽  
Author(s):  
M. Mishima ◽  
K. Kawakami ◽  
K. Higashiya ◽  
T. Fukunaga ◽  
T. Ooka ◽  
...  
Keyword(s):  
Chest Wall ◽  
Random Noise ◽  
Peripheral Resistance ◽  
Normal Subjects ◽  
Frequency Characteristics ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
The Real ◽  
Peripheral Airway ◽  
Chronic Pulmonary Emphysema

We measured the frequency characteristics (at 10–40 Hz) of airway (Za) and tissue (Zt) impedances in cases of chronic obstructive pulmonary disease [asthmatic bronchitis (AB), chronic pulmonary emphysema (CPE)] and interstitial pneumonitis (IP) by use of an improved random noise oscillation and body box method. The results were then compared with those obtained for normal subjects. The real part of Za was markedly elevated in patients with AB but only slightly elevated in those with CPE. To interpret these data we used an electromechanical analogue including serial inhomogeneity with shunt impedance. From this model we concluded that AB causes both the central and peripheral airway resistances to increase, while CPE brings about a rise mainly in peripheral resistance. In IP patients, only the imaginary part of Zt decreased, which might reflect the decrease in both lung and chest wall compliance. In CPE patients, but not in AB patients, the real part of Zt fell. These data were consistent with the assumption that the decrease in mass per unit volume of lung tissue and hyperinflation of the chest wall in CPE patients might lower the tissue resistances.

Detection of expiratory flow limitation during exercise in COPD patients

1997 ◽  
Vol 82 (3) ◽  
pp. 723-731 ◽  
Author(s):  
Nickolaos G. Koulouris ◽  
Ioanna Dimopoulou ◽  
Päivi Valta ◽  
Richard Finkelstein ◽  
Manuel G. Cosio ◽  
...  
Keyword(s):  
Normal Subjects ◽  
Chronic Obstructive ◽  
Flow Limitation ◽  
Expiratory Flow Limitation ◽  
Obstructive Pulmonary Disease ◽  
Normal Limits ◽  
Volume Curve ◽  
Copd Patients ◽  
Flow Volume Curve ◽  
Expiratory Flow

Koulouris, Nickolaos G., Ioanna Dimopoulou, Päivi Valta, Richard Finkelstein, Manuel G. Cosio, and J. Milic-Emili.Detection of expiratory flow limitation during exercise in COPD patients. J. Appl. Physiol. 82(3): 723–731, 1997.—The negative expiratory pressure (NEP) method was used to detect expiratory flow limitation at rest and at different exercise levels in 4 normal subjects and 14 patients with chronic obstructive pulmonary disease (COPD). This method does not require performance of forced expirations, nor does it require use of body plethysmography. It consists in applying negative pressure (−5 cmH2O) at the mouth during early expiration and comparing the flow-volume curve of the ensuing expiration with that of the preceding control breath. Subjects in whom application of NEP does not elicit an increase in flow during part or all of the tidal expiration are considered flow limited. The four normal subjects were not flow limited up to 90% of maximal exercise power output (W˙max). Five COPD patients were flow limited at rest, 9 were flow limited at one-third W˙max, and 12 were flow limited at two-thirdsW˙max. Whereas in all patients who were flow limited at rest the maximal O2 uptake was below the normal limits, this was not the case in most of the other patients. In conclusion, NEP provides a rapid and reliable method to detect expiratory flow limitation at rest and during exercise.

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.

Viscoelastic behavior of lung and chest wall in dogs determined by flow interruption

1989 ◽  
Vol 67 (6) ◽  
pp. 2219-2229 ◽  
Author(s):  
T. Similowski ◽  
P. Levy ◽  
C. Corbeil ◽  
M. Albala ◽  
R. Pariente ◽  
...  
Keyword(s):  
Frequency Dependence ◽  
Chest Wall ◽  
Viscoelastic Behavior ◽  
Constant Flow ◽  
Pulmonary Tissue ◽  
Airway Occlusion ◽  
Chest Wall Mechanics ◽  
Flow Interruption ◽  
Overall Resistance ◽  
Pressure Changes

Pulmonary and chest wall mechanics were studied in six anesthetized paralyzed dogs, by use of the technique of rapid airway occlusion during constant flow inflation. Analysis of the pressure changes after flow interruption allowed us to partition the overall resistance of the lung (Rl) and chest wall (Rw) and total respiratory system (Rrs) into two components, one (Rinit) reflecting in the lung airway resistance (Raw), the other (delta R) reflecting primarily the viscoelastic properties of the pulmonary and chest wall tissues. The effects of varying inspiratory flow and inflation volume were interpreted in terms of frequency dependence of resistance, by using a spring-and-dashpot model previously proposed and substantiated by Bates et al. (Proc. 9th Annu. Conf. IEEE Med. Biol. Soc., 1987, vol. 3, p. 1802-1803). We observed that 1) Raw and Rw,init were nearly equal and small relative to Rl and Rw (both were unaffected by flow); 2) Rrs,init decreased slightly with increasing volume; 3) both delta Rl and delta Rw decreased with increasing flow and increased with increasing lung volume. These changes were manifestations of frequency dependence of delta R, as it is predicted by the model; 4) Rrs, Rl, and Rw followed the same trends as delta R. These results corroborate data previously reported in the literature with the use of different techniques to measure airways and pulmonary tissue resistances and confirm that the use of Rl to assess bronchial reactivity is problematic. The interrupter techniques provides a convenient way to obtain Raw values, as well as analogs of lung and chest wall tissue resistances in intact dogs.

The effect of posture on asynchronous chest wall movement in COPD

2013 ◽  
Vol 114 (8) ◽  
pp. 1066-1075 ◽  
Author(s):  
Rita Priori ◽  
Andrea Aliverti ◽  
André L. Albuquerque ◽  
Marco Quaranta ◽  
Paul Albert ◽  
...  
Keyword(s):  
Chest Wall ◽  
Body Position ◽  
Respiratory Muscles ◽  
Forced Expiratory Volume ◽  
Chronic Obstructive ◽  
Quiet Breathing ◽  
Obstructive Pulmonary Disease ◽  
Rib Cage ◽  
Copd Patients ◽  
Supine Posture

Chronic obstructive pulmonary disease (COPD) patients often show asynchronous movement of the lower rib cage during spontaneous quiet breathing and exercise. We speculated that varying body position from seated to supine would influence rib cage asynchrony by changing the configuration of the respiratory muscles. Twenty-three severe COPD patients (forced expiratory volume in 1 s = 32.5 ± 7.0% predicted) and 12 healthy age-matched controls were studied. Measurements of the phase shift between upper and lower rib cage and between upper rib cage and abdomen were performed with opto-electronic plethysmography during quiet breathing in the seated and supine position. Changes in diaphragm zone of apposition were measured by ultrasounds. Control subjects showed no compartmental asynchronous movement, whether seated or supine. In 13 COPD patients, rib cage asynchrony was noticed in the seated posture. This asynchrony disappeared in the supine posture. In COPD, upper rib cage and abdomen were synchronous when seated, but a strong asynchrony was found in supine. The relationships between changes in diaphragm zone of apposition and volume variations of chest wall compartments supported these findings. Rib cage paradox was noticed in approximately one-half of the COPD patients while seated, but was not related to impaired diaphragm motion. In the supine posture, the rib cage paradox disappeared, suggesting that, in this posture, diaphragm mechanics improves. In conclusion, changing body position induces important differences in the chest wall behavior in COPD patients.

scholarly journals Correlation between cardiorespiratory coupling and six-minute walking tests in patients with chronic obstructive pulmonary disease

2020 ◽  
Author(s):  
Yu-Chen Huang ◽  
Ting-Yu Lin ◽  
Hau-Tieng Wu ◽  
Po-Jui Chang ◽  
Chun-Yu Lo ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Normal Subjects ◽  
Walking Distance ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Copd Patients ◽  
Forward Stepwise ◽  
Cardiorespiratory Coupling ◽  
Clinical Potential

Abstract Background : Cardiovascular disease is a common comorbidity and cause of mortality among patients with chronic obstructive pulmonary disease (COPD). However, the interaction between the heart and lungs in COPD patients has yet to be fully elucidated.Aim : Our objective in this study was to characterize cardiorespiratory interactions in terms of cardiorespiratory coupling (CRC) using the synchrogram index of the heart rate and respiration flow signals.Methods : This prospective study examined 10 normal subjects and 55 COPD patients. Linear regression and forward stepwise regression were used to determine the correlation between the synchrogram index and the six-minute walking test.Results : K-means clustering analysis was used to separate the 55 COPD patients into a synchronized group (median 0.89 (0.64-0.97), n=43) and a desynchronized group (median 0.23 (0.02-0.51), n=12) based on the synchrogram index. In this study, the synchrogram index was significantly correlated with the six-minute walking distance (r 2 =0.3, sigma T=0.02) and the distance saturation product (r 2 =0.3, sigma T =0.03). Note that age was a significant confounding factor.Conclusion : The synchrogram index shows clinical potential for the stratification of COPD patients for treatment.

COMPARISON BETWEEN CURB-65 AND BAP-65 IN THE PREDICTION OF MECHANICAL VENTILATION IN PATIENTS WITH THE EXACERBATION OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE

2017 ◽  
pp. 60-63
Author(s):  
Van Dong Tran ◽  
Van Chi Nguyen ◽  
Ngoc Son Do
Keyword(s):  
Mechanical Ventilation ◽  
Pulmonary Disease ◽  
Area Under Curve ◽  
Invasive Mechanical Ventilation ◽  
High Accuracy ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Mechanically Ventilated ◽  
Copd Patients ◽  
Exacerbation Of Copd

Objectives: to compare between CURB-65 and BAP-65 in the prediction of mechanical ventilation in patients with the exacerbation of chronic obstrutive pulmonary disease (COPD). Study design: Retrospective study. Subjects and methods: 419 COPD patients were admitted to Emergency Department of Bach Mai Hospital from January 01, 2013 to June 06, 2014. Results: There were 378 patients (90.2%) who were not mechanically ventilated, 41 patients (9.8%) who were on invasive mechanical ventilation. The area under curve (AUROC) of BAP-65 was higher than that of CURB-65 in the predection of mechanical ventilation : 0.93 95% CI: 0.90-0.95) and 0.90 95% CI: 0.87-0.93) (p= 0,272) respectively. Conclusions: Both BAP-65 and CURB-65 could be seen as a useful tool for the risk statification for initiation of mechanical ventilation on patients with the exacerbation of COPD, however, BAP-65 was high accuracy than that of CURB-65. Key words: Mechanical ventilation, CURB-65, BAP-65, Exacerbation of COPD.

Partitioning of respiratory mechanics in mechanically ventilated patients

1991 ◽  
Vol 71 (6) ◽  
pp. 2425-2433 ◽  
Author(s):  
G. Polese ◽  
A. Rossi ◽  
L. Appendini ◽  
G. Brandi ◽  
J. H. Bates ◽  
...  
Keyword(s):  
Pulmonary Edema ◽  
Chest Wall ◽  
Respiratory System ◽  
Lung Mechanics ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Respiratory System Mechanics ◽  
Ventilated Patients

In ten mechanically ventilated patients, six with chronic obstructive pulmonary disease (COPD) and four with pulmonary edema, we have partitioned the total respiratory system mechanics into the lung (l) and chest wall (w) mechanics using the esophageal balloon technique together with the airway occlusion technique during constant-flow inflation (J. Appl. Physiol. 58: 1840–1848, 1985). Intrinsic positive end-expiratory pressure (PEEPi) was present in eight patients (range 1.1–9.8 cmH2O) and was due mainly to PEEPi,L (80%), with a minor contribution from PEEPi,w (20%), on the average. The increase in respiratory elastance and resistance was determined mainly by abnormalities in lung elastance and resistance. Chest wall elastance was slightly abnormal (7.3 +/- 2.2 cmH2O/l), and chest wall resistance contributed only 10%, on the average, to the total. The work performed by the ventilator to inflate the lung (WL) averaged 2.04 +/- 0.59 and 1.25 +/- 0.21 J/l in COPD and pulmonary edema patients, respectively, whereas Ww was approximately 0.4 J/l in both groups, i.e., close to normal values. We conclude that, in mechanically ventilated patients, abnormalities in total respiratory system mechanics essentially reflect alterations in lung mechanics. However, abnormalities in chest wall mechanics can be relevant in some COPD patients with a high degree of pulmonary hyperinflation.

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