THE EFFICIENCY OF THE RESPIRATORY MUSCLES IN OBESITY

1961 ◽  
Vol 39 (8) ◽  
pp. 1215-1222 ◽  
Author(s):  
Reuben M. Cherniack ◽  
Clarence A. Guenter
Keyword(s):  
Chest Wall ◽  
Respiratory Muscles ◽  
Normal Subjects ◽  
Oxygen Cost ◽  
Chest Wall Compliance ◽  
Elastic Resistance ◽  
Lower Lung ◽  
Wall Compliance ◽  
Obese Subjects ◽  
Work Done

The work done to overcome the elastic resistance and the efficiency of the respiratory muscles were determined in normal and obese subjects. The work done was no greater in the obese subjects, but the efficiency of the muscles was low. These findings suggest that the high oxygen cost of breathing in obesity is due to inefficient respiratory muscles rather than to an increased amount of work required to overcome elastic resistance. When an extrapulmonary elastic resistance was applied to the normal subjects, the compliance of the chest wall and the efficiency of the respiratory muscles fell to the level of that in the obese. This suggests that the inefficiency of the respiratory muscles of obese individuals may have been due to the reduced chest wall compliance or to the lower lung volume at which ventilation took place.

Compliance of the chest wall in chronic bronchitis and emphysema

1963 ◽  
Vol 18 (4) ◽  
pp. 707-711 ◽  
Author(s):  
R. M. Cherniack ◽  
A. Hodson
Keyword(s):  
Airway Obstruction ◽  
Chronic Bronchitis ◽  
Chest Wall ◽  
Respiratory System ◽  
Vital Capacity ◽  
Normal Subjects ◽  
Chest Wall Compliance ◽  
Paradoxical Finding ◽  
Wall Compliance ◽  
Work Done

The respiratory rate was found to be faster and the tidal volume lower than normal in patients with chronic bronchitis and emphysema. The compliance of the total respiratory system, the lungs, and the chest wall was measured in 11 normal subjects and 13 patients with chronic bronchitis, 11 of whom had also developed emphysema. The compliance of the total respiratory system was lower than in the normals in the patients with chronic bronchitis. This was entirely attributable to a reduction in the compliance of the chest wall, that of the lungs being similar to that of the normals. The vital capacity appeared to be related to the compliance of the total respiratory system and was reduced in the patients with chronic bronchitis and emphysema largely because of a diminished distensibility of the chest wall. It is suggested that the low chest wall compliance may explain the paradoxical finding of rapid shallow respirations in these patients with airway obstruction who theoretically would have been expected to breathe slowly and deeply. It is further suggested that the diminished distensibility of the chest wall in patients with chronic bronchitis and emphysema would necessitate an increase in the amount of work done in order to breathe and, therefore, likely contributes to the disability in this disease. Submitted on April 18, 1962

Developmental changes in chest wall compliance in infancy and early childhood

1995 ◽  
Vol 78 (1) ◽  
pp. 179-184 ◽  
Author(s):  
C. Papastamelos ◽  
H. B. Panitch ◽  
S. E. England ◽  
J. L. Allen
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Respiratory Muscles ◽  
Lung Compliance ◽  
Developmental Changes ◽  
System Function ◽  
Manual Ventilation ◽  
Chest Wall Compliance ◽  
Wall Stiffness ◽  
Wall Compliance

Development of chest wall stiffness between infancy and adulthood has important consequences for respiratory system function. To test the hypothesis that there is substantial stiffening of the chest wall in the first few years of life, we measured passive chest wall compliance (Cw) in 40 sedated humans 2 wk-3.5 yr old. Respiratory muscles were relaxed with manual ventilation applied during the Mead-Whittenberger technique. Respiratory system compliance (Crs) and lung compliance (Cl) were calculated from airway opening pressure, transpulmonary pressure, and tidal volume. Cw was calculated as 1/Cw = 1/Crs - 1/Cl during manual ventilation. Mean Cw per kilogram in infants < 1 yr old was significantly higher than that in children > 1 yr old (2.80 +/- 0.87 vs. 2.04 +/- 0.51 ml.cmH2O–1.kg-1; P = 0.002). There was an inverse linear relationship between age and mean Cw per kilogram (r = -0.495, slope -0.037; P < 0.001). In subjects with normal Cl during spontaneous breathing, Cw/spontaneous Cl was 2.86 +/- 1.06 in infants < 1 yr old and 1.33 +/- 0.36 in older children (P = 0.005). We conclude that in infancy the chest wall is nearly three times as compliant as the lung and that by the 2nd year of life chest wall stiffness increases to the point that the chest wall and lung are nearly equally compliant, as in adulthood. Stiffening of the chest wall may play a major role in developmental changes in respiratory system function such as the ability to passively maintain resting lung volume and improved ventilatory efficiency afforded by reduced rib cage distortion.

A pinhole method for measuring chest wall compliance

1983 ◽  
Vol 54 (4) ◽  
pp. 1157-1160
Author(s):  
J. L. Grant ◽  
D. P. Moulton
Keyword(s):  
Chest Wall ◽  
Respiratory Muscles ◽  
Esophageal Pressure ◽  
Repeated Measurements ◽  
Needle Valve ◽  
Chest Wall Compliance ◽  
Pressure Line ◽  
Wall Compliance ◽  
The Subject

We describe a method of measuring chest wall compliance (Cw) that readily detects whether respiratory muscles are relaxed. The method simulates a normal slow sigh, with the subject exhaling through a needle valve. Cw is calculated from the slope of the volume-esophageal pressure line. With relaxed subjects, repeated measurements yield similar slopes. When subjects cannot relax, the volume-pressure line is irregular and variable. In 26 subjects who could relax, Cw averaged 0.208 +/- 0.05 (SD) l/cmH2O.

scholarly journals Compliance of the respiratory system and its components in health and obesity

1960 ◽  
Vol 15 (3) ◽  
pp. 377-382 ◽  
Author(s):  
A. Naimark ◽  
R. M. Cherniack
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Work Of Breathing ◽  
Normal Subjects ◽  
Respiratory Compliance ◽  
Elastic Resistance ◽  
Normal Individuals ◽  
Obese Subjects ◽  
The Difference ◽  
Mean Compliance

The compliance of the total respiratory system and its components was studied in 24 normal and 12 obese spontaneously breathing unanesthetized subjects. The mean compliance of the total respiratory system was .119 l/cm H2O in normal individuals, but was .052 l/cm H2O in obese subjects. The difference indicated an increased elastic resistance to distention. The compliance of the lung in obese individuals was not different from that of the normals. The compliance of the chest wall was .224 l/cm H2O in normal subjects and was .077 l/cm H2O in obese individuals. In contrast to normal subjects, total respiratory compliance was markedly reduced by recumbency in obese individuals. This was entirely due to a further increase in the resistance of the chest wall. A significant correlation was demonstrated between vital capacity and total respiratory compliance in normal and obese subjects. It has been estimated that of the increase in the mechanical work of breathing in obesity is due to elastic work done on the chest wall. Submitted on November 2, 1959

Compliance of chest wall in obese subjects

1984 ◽  
Vol 57 (2) ◽  
pp. 403-407 ◽  
Author(s):  
P. M. Suratt ◽  
S. C. Wilhoit ◽  
H. S. Hsiao ◽  
R. L. Atkinson ◽  
D. F. Rochester
Keyword(s):  
Chest Wall ◽  
Muscle Relaxation ◽  
Obese Subject ◽  
Constant Flow ◽  
Pulse Flow ◽  
Chest Wall Compliance ◽  
Wall Compliance ◽  
Obese Subjects ◽  
Normal Males ◽  
The One

Whereas studies in awake subjects have demonstrated that chest wall compliance (Ccw) is low in obese subjects, the one study performed on paralyzed obese subject found Ccw to be normal. The purpose of this study was to measure Ccw in awake obese subjects with the pulse-flow technique, a method which appears to detect respiratory muscle relaxation. Seven normal males, 14 obese males, and 8 obese females [body mass index (BMI) varied from 20 to 83 kg/m2] were studied in the seated position. Ccw was measured by blowing air at a constant flow into the mouth and lungs for approximately 2 s and calculated by dividing airflow in liters per second by the change in esophageal minus body surface pressure in centimeters of water per second. In normal and obese subjects we found no correlation between BMI and Ccw. We conclude that obesity does not decrease Ccw.

Respiratory and Laryngeal Function During Whispering

1991 ◽  
Vol 34 (4) ◽  
pp. 761-767 ◽  
Author(s):  
Elaine T. Stathopoulos ◽  
Jeannette D. Hoit ◽  
Thomas J. Hixon ◽  
Peter J. Watson ◽  
Nancy Pearl Solomon
Keyword(s):  
Young Adults ◽  
Chest Wall ◽  
Voice Disorders ◽  
Normal Subjects ◽  
High Rate ◽  
Lung Volumes ◽  
Laryngeal Function ◽  
Tracheal Pressure ◽  
Lower Lung ◽  
Resistive Loads

Established procedures for making chest wall kinematic observations (Hoit & Hixon, 1987) and pressure-flow observations (Smitheran & Hixon, 1981) were used to study respiratory and laryngeal function during whispering and speaking in 10 healthy young adults. Results indicate that whispering involves generally lower lung volumes, lower tracheal pressures, higher translaryngeal flows, lower laryngeal airway resistances, and fewer syllables per breath group when compared to speaking. The use of lower lung volumes during whispering than speaking may reflect a means of achieving different tracheal pressure targets. Reductions in the number of syllables produced per breath group may be an adjustment to the high rate of air expenditure accompanying whispering compared to speaking. Performance of the normal subjects studied in this investigation does not resemble that of individuals with speech and voice disorders characterized by low resistive loads.

Low-frequency respiratory mechanical impedance in the rat

1987 ◽  
Vol 63 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Z. Hantos ◽  
B. Daroczy ◽  
B. Suki ◽  
S. Nagy
Keyword(s):  
Frequency Dependence ◽  
Chest Wall ◽  
Low Frequency ◽  
Mechanical Impedance ◽  
Total Resistance ◽  
Low Frequencies ◽  
Chest Wall Compliance ◽  
Before And After ◽  
Airway Opening ◽  
Wall Compliance

modified forced oscillatory technique was used to determine the respiratory mechanical impedances in anesthetized, paralyzed rats between 0.25 and 10 Hz. From the total respiratory (Zrs) and pulmonary impedance (ZL), measured with pseudorandom oscillations applied at the airway opening before and after thoracotomy, respectively, the chest wall impedance (ZW) was calculated as ZW = Zrs - ZL. The pulmonary (RL) and chest wall resistances were both markedly frequency dependent: between 0.25 and 2 Hz they contributed equally to the total resistance falling from 81.4 +/- 18.3 (SD) at 0.25 Hz to 27.1 +/- 1.7 kPa.l–1 X s at 2 Hz. The pulmonary compliance (CL) decreased mildly, from 2.78 +/- 0.44 at 0.25 Hz to 2.36 +/- 0.39 ml/kPa at 2 Hz, and then increased at higher frequencies, whereas the chest wall compliance declined monotonously from 4.19 +/- 0.88 at 0.25 Hz to 1.93 +/- 0.14 ml/kPa at 10 Hz. Although the frequency dependence of ZW can be interpreted on the basis of parallel inhomogeneities alone, the sharp fall in RL together with the relatively constant CL suggests that at low frequencies significant losses are imposed by the non-Newtonian resistive properties of the lung tissue.

scholarly journals CAN THEORETICAL VALUES FOR CHEST WALL COMPLIANCE BE USED IN ARDS PATIENTS?

2015 ◽  
Vol 3 (Suppl 1) ◽  
pp. A999
Author(s):  
GQ Chen ◽  
M Xu ◽  
XL Chen ◽  
N Rittayamai ◽  
M Kim ◽  
...  
Keyword(s):  
Chest Wall ◽  
Chest Wall Compliance ◽  
Wall Compliance
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