Respiratory mechanics in normal bonnet and rhesus monkeys

1979 ◽  
Vol 46 (1) ◽  
pp. 166-175 ◽  
Author(s):  
P. C. Kosch ◽  
J. R. Gillespie ◽  
J. D. Berry
Keyword(s):  
Chest Wall ◽  
Mammalian Species ◽  
Lung Volumes ◽  
Chest Wall Compliance ◽  
Wide Range ◽  
Residual Capacity ◽  
Static Mechanical ◽  
Wall Compliance ◽  
Trapped Gas ◽  
Gas Volume

We measured lung volumes and quasi-static volume-pressure relationships in 22 normal upright bonnet (Macaca radiata) and 12 rhesus (M. mulatta) monkeys. In comparison with interspecies pulmonary function/body weight regressions our monkeys' lung volumes are larger and their lungs are considerably more compliant, but their chest wall compliance is similar to a wide range of mammalian species. However, chest wall compliance of our monkeys was found to be considerably less than that of other more commonly used experimental mammals such as dogs, cats, and rodents. The monkey chest walls were found to be about four times as stiff (3.3 +/- 0.1 (ml/cmH2O)/kg), whereas their lungs were nearly twice as compliant (9.2 +/- 0.7 (ml/cmH2O)/kg) compared to those of supine beagle dogs. Thus, their stiff chest wall sets their functional residual capacity (64.1 +/- 1.2% TLC30) at a much larger percentage of total lung capacity (TLC30) than that of the supine beagle dog (33.8% TLC30). Residual volume (13.2 +/- 1.9% TLC30) equaled the trapped gas volume after bilateral thoracotomy and was set by airway closure. We found more hysteresis area in the chest wall than in the lungs. Our measurements indicate that the static mechanical behavior of the respiratory system of the monkey compares well to man and that the monkey has considerable merit as an animal model for human respiratory function and disease research.

Respiratory mechanics in the anesthetized rat

1978 ◽  
Vol 45 (2) ◽  
pp. 255-260 ◽  
Author(s):  
Y. L. Lai ◽  
J. Hildebrandt
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Esophageal Pressure ◽  
Gas Content ◽  
Lung Capacity ◽  
Consistent Change ◽  
Residual Capacity ◽  
Wall Compliance ◽  
The Difference ◽  
Body Plethysmograph

Functional residual capacity (FRC) and pressure-volume (PV) curves of the lung, chest wall, and total respiratory system were studied in 15 anesthetized rats, weighing 307 +/- 10 (SE) g. Pleural pressure was estimated from the esophageal pressure measured with a water-filled catheter. The FRC determined by body plethysmograph was slightly and significantly larger than FRC determined from saline displacement of excised lungs. The difference may be accounted for by O2 uptake by lung tissue, escape of CO2 through the pleura, and abdominal gas. Paralysis in the prone position did not affect FRC, and abdominal gas content contributed only slightly to the FRC measured by body plethysmograph. Values of various pulmonary parameters (mean +/- SE) were as follows: residual volume, 1.26 +/- 0.13 ml; FRC, 2.51 +/- 0.20 ml; total lung capacity, 12.23 +/- 0.55 ml; compliance of the lung, 0.90 +/- 0.06 ml/cmH2O; chest wall compliance, 1.50 +/- 0.11 ml/cmH2O; and respiratory system compliance, 0.57 +/- 0.03 ml/cmH2O. The lung PV curve did not show a consistent change after the chest was opened.

scholarly journals Lung volumes and respiratory mechanics in elastase-induced emphysema in mice

2008 ◽  
Vol 105 (6) ◽  
pp. 1864-1872 ◽  
Author(s):  
Z. Hantos ◽  
Á. Adamicza ◽  
T. Z. Jánosi ◽  
M. V. Szabari ◽  
J. Tolnai ◽  
...  
Keyword(s):  
Mouse Model ◽  
Low Frequency ◽  
Forced Oscillations ◽  
Mechanical Parameters ◽  
Tissue Destruction ◽  
Lung Volumes ◽  
Lung Capacity ◽  
Thoracic Gas Volume ◽  
Residual Capacity ◽  
Gas Volume

Absolute lung volumes such as functional residual capacity, residual volume (RV), and total lung capacity (TLC) are used to characterize emphysema in patients, whereas in animal models of emphysema, the mechanical parameters are invariably obtained as a function of transrespiratory pressure (Prs). The aim of the present study was to establish a link between the mechanical parameters including tissue elastance (H) and airway resistance (Raw), and thoracic gas volume (TGV) in addition to Prs in a mouse model of emphysema. Using low-frequency forced oscillations during slow deep inflation, we tracked H and Raw as functions of TGV and Prs in normal mice and mice treated with porcine pancreatic elastase. The presence of emphysema was confirmed by morphometric analysis of histological slices. The treatment resulted in an increase in TGV by 51 and 44% and a decrease in H by 57 and 27%, respectively, at 0 and 20 cmH2O of Prs. The Raw did not differ between the groups at any value of Prs, but it was significantly higher in the treated mice at comparable TGV values. In further groups of mice, tracheal sounds were recorded during inflations from RV to TLC. All lung volumes but RV were significantly elevated in the treated mice, whereas the numbers and size distributions of inspiratory crackles were not different, suggesting that the airways were not affected by the elastase treatment. These findings emphasize the importance of absolute lung volumes and indicate that tissue destruction was not associated with airway dysfunction in this mouse model of emphysema.

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

Measurement of high lung volumes by nitrogen washout method

1994 ◽  
Vol 77 (3) ◽  
pp. 1562-1564 ◽  
Author(s):  
Y. Sivan ◽  
J. Hammer ◽  
C. J. Newth
Keyword(s):  
Lung Volume ◽  
Human Infants ◽  
Lung Volumes ◽  
Nitrogen Washout ◽  
Thoracic Gas Volume ◽  
Residual Capacity ◽  
The Difference ◽  
Gas Dilution ◽  
Spontaneously Breathing ◽  
Gas Volume

Studies on human infants suggested that thoracic gas volume (TGV) measured at end exhalation may not depict the true TGV and may differ from TGV measured from a series of higher lung volumes and corrected for the volume added. This was explained by gas trapping. If true, we should expect the discrepancy to be more pronounced when functional residual capacity (FRC) and higher lung volumes are measured by gas dilution techniques. We studied lung volumes above FRC by the nitrogen washout technique in 12 spontaneously breathing rhesus monkeys (5.0–11.3 kg wt; 42 compared measurements). Lung volumes directly measured were compared with preset lung volumes achieved by artificial inflation of the lungs above FRC with known volumes of air (100–260 ml). Measured lung volume strongly correlated with and was not significantly different from present lung volume (P = 0.05; r = 0.996). The difference between measured and preset lung volume was 0–5% in 41 of 42 cases [1 +/- 0.4% (SE)]. The direction of the difference was unpredictable; in 22 of 42 cases the measured volume was larger than the preset volume, but in 17 of 42 cases it was smaller. The difference was not affected by the volume of gas artificially inflated into the lungs. We conclude that, overall, lung volumes above FRC can be reliably measured by the nitrogen washout technique and that FRC measurements by this method reasonably reflect true FRC.

Problems in measurement of thoracic gas volume in infancy

1982 ◽  
Vol 52 (4) ◽  
pp. 995-999 ◽  
Author(s):  
C. S. Beardsmore ◽  
J. Stocks ◽  
M. Silverman
Keyword(s):  
Functional Residual Capacity ◽  
Clinical Status ◽  
Pleural Pressure ◽  
Whole Body ◽  
Airway Closure ◽  
Lung Volumes ◽  
Airway Occlusion ◽  
Thoracic Gas Volume ◽  
Residual Capacity ◽  
Gas Volume

Thoracic gas volume (TGV) was measured with a whole-body plethysmograph in 20 infants at functional residual capacity (FRC) and at a series of higher lung volumes achieved by artificial inflation of the lungs with known volumes of air after airway occlusion. There was a discrepancy between the corrected values of TGV measured at high and low lung volumes in nine infants; in six cases TGV measured at high lung volumes exceeded that measured at FRC, and in three cases it was reduced when compared with the measurement made at FRC. These changes were not related to age, size, or clinical status and could be explained by airway closure at FRC, combined with an uneven distribution of pleural pressure.

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.

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