Mechanical work of breathing derived from rib cage and abdominal V-P partitioning

1976 ◽  
Vol 41 (5) ◽  
pp. 752-763 ◽  
Author(s):  
M. D. Goldman ◽  
G. Grimby ◽  
J. Mead
Keyword(s):  
Chest Wall ◽  
Work Of Breathing ◽  
Mechanical Work ◽  
Quiet Breathing ◽  
Campbell Diagram ◽  
Rib Cage ◽  
Abdominal Musculature ◽  
Work Done ◽  
Inspiratory Work

Estimates of the mechanical work of breathing derived from measurements of separate rib cage and abdominal volume displacements, each plotted against transthoracic pressure, include the elastic cost of chest wall distortion which may occur during breathing. Inspiratory work is partitioned between the diaphragm and the rib cage musculature by adding measurements of transabdominal pressure. The mechanical work of breathing derived from separate rib cage and abdominal volume-pressure (V-P) tracings (the sum of work done by the diaphragm, rib cage, and abdominal musculature) is compared with ventilatory work estimated from the Campbell diagram (which does not include any distortional work). During resting breathing the two estimates are closely comparable, consistent with little or no distortion of the chest wall during quiet breathing. As ventilation increases, the estimate developed from rib cage and abdominal tracings reveals systematically greater mechanical work than is estimated from the Campbell diagram, consistent with distortion of the chest wall from the relaxed thoracoabdominal configuration at higher levels of ventilation. At ventilations achieved during exercise, the Campbell diagram may underestimate the work of breathing by up to 25%.

Relationships between stimulus and work of breathing at different lung volumes

1962 ◽  
Vol 17 (6) ◽  
pp. 917-921 ◽  
Author(s):  
Robert Marshall
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Viscoelastic Properties ◽  
Inverse Relationship ◽  
Work Of Breathing ◽  
Intrathoracic Pressure ◽  
Mechanical Work ◽  
Lung Volumes ◽  
Pressure Swing ◽  
Work Done

An electrophrenic stimulator has been used on anesthetized cats and dogs to investigate the intrathoracic pressure produced by a given stimulus at different lung volumes. With a stimulus of fixed strength the resulting intrathoracic pressure swing bears an inverse relationship to lung volume. The mechanical work done in response to a given stimulus is dependent on the viscoelastic properties of the lungs and chest wall. The muscular work resulting from a stimulus and the efficiency of the chest muscles are also dependent on the position of the diaphragm and possibly on the position of the remainder of the chest wall. Submitted on February 27, 1962

scholarly journals Calculating the work of breathing during mechanical ventilation.

2021 ◽  
Vol 2 (2) ◽  
pp. 71-72
Author(s):  
Mia Shokry ◽  
Melina Simonpietri ◽  
Kimiyo Yamasaki
Keyword(s):  
Tidal Volume ◽  
Chest Wall ◽  
Work Of Breathing ◽  
Esophageal Pressure ◽  
Campbell Diagram ◽  
Chest Wall Compliance ◽  
Wall Compliance ◽  
Left Figure ◽  
Inspiratory Work ◽  
Axis Versus

Left figure: Passive patient esophageal pressure (Pes) in cmH2O on x-axis versus tidal volume in ml on y-axis. Green dashed line represents the chest wall compliance Right figure: same patient actively breathing on pressure support ventilation. (Pes) in cmH2O on x-axis versus tidal volume in ml on y-axis. Green dashed line represents the chest wall compliance. Red shaded area is the Campbell diagram representing the inspiratory work of breathing

Diaphragmatic work of breathing in premature human infants

1987 ◽  
Vol 62 (4) ◽  
pp. 1410-1415 ◽  
Author(s):  
B. G. Guslits ◽  
S. E. Gaston ◽  
M. H. Bryan ◽  
S. J. England ◽  
A. C. Bryan
Keyword(s):  
Lung Disease ◽  
Preterm Infants ◽  
Work Of Breathing ◽  
Mechanical Efficiency ◽  
Strongly Correlated ◽  
Intercostal Muscle ◽  
Human Infants ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Inspiratory Work

Present methods of assessing the work of breathing in human infants do not account for the added load when intercostal muscle activity is lost and rib cage distortion occurs. We have developed a technique for assessing diaphragmatic work in this circumstance utilizing measurements of transdiaphragmatic pressure and abdominal volume displacement. Eleven preterm infants without evidence of lung disease were studied. During periods of minimal rib cage distortion, inspiratory diaphragmatic work averaged 5.9 g X cm X ml-1, increasing to an average of 12.4 g X cm X ml-1 with periods of paradoxical rib cage motion (P less than 0.01). Inspiratory work was strongly correlated with the electrical activity of the diaphragm as measured from its moving time average (P less than 0.05). Assuming a mechanical efficiency of 4% in these infants, the caloric cost of diaphragmatic work may reach 10% of their basal metabolic rate in periods with rib cage distortion. When lung disease is superimposed, the increased metabolic demands of the diaphragm may predispose preterm infants to fatigue and may contribute to a failure to grow.

Chest Wall Responses to Rebreathing in Halothane-anesthetized Dogs

1995 ◽  
Vol 83 (4) ◽  
pp. 835-843. ◽  
Author(s):  
David O. Warner ◽  
Michael J. Joyner ◽  
Erik L. Ritman
Keyword(s):  
Chest Wall ◽  
Muscle Activity ◽  
Respiratory Muscle ◽  
Species Differences ◽  
Minimum Alveolar Concentration ◽  
Electromyographic Activity ◽  
Quiet Breathing ◽  
Rib Cage ◽  
Expiratory Muscle ◽  
Anesthetized Dogs

Background The pattern of respiratory muscle use during halothane-induced anesthesia differs markedly among species breathing quietly. In humans, halothane accentuates phasic activity in rib cage and abdominal expiratory muscles, whereas activity in the parasternal intercostal muscles is abolished. In contrast, halothane abolishes phasic expiratory muscle activity during quiet breathing in dogs, but parasternal muscle activity is maintained. Respiratory muscle responses to CO2 rebreathing were measured in halothane-anesthetized dogs to determine if species differences present during quiet breathing persist over a wide range of central respiratory drive. Methods Chronic electromyogram electrodes were implanted in three expiratory agonists (the triangularis sterni, transversus abdominis, and external oblique muscles) and three inspiratory agonists (the parasternal intercostal muscle, costal and crural diaphragm) of six mongrel dogs. After a 1-month recovery period, the dogs were anesthetized in the supine position with halothane. The rebreathing response was determined by Read's method during anesthesia with stable 1 and 2 minimum alveolar end-tidal concentrations of halothane. CO2 concentrations were measured in the rebreathing bag using an infrared analyzer. Chest wall motion was measured by fast three-dimensional computed tomographic scanning. Results Halothane concentration did not significantly affect the slope of the relationship between minute ventilation (VE) and PCO2 (0.34 +/- 0.04 [M +/- SE] and 0.28 +/- 0.05 l.min-1.mmHg-1 during 1 and 2 minimum alveolar concentration anesthesia, respectively). However, 2 minimum alveolar concentration anesthesia did significantly decrease the calculated VE at a PCO2 of 60 mmHg (from 7.4 +/- 1.2 to 4.0 +/- 0.6 l.min-1), indicating a rightward shift in the response relationship. No electromyographic activity was observed in any expiratory muscle before rebreathing. Rebreathing produced electromyographic activity in at least one expiratory muscle in only two dogs. Rebreathing significantly increased electromyographic activity in all inspiratory agonists. Rebreathing significantly increased inspiratory thoracic volume change (delta Vth), with percentage of delta Vth attributed to outward rib cage displacement increasing over the course of rebreathing during 1 minimum alveolar concentration anesthesia (from 33 +/- 6% to 48 +/- 2% of delta Vth). Conclusions Rebreathing did not produce expiratory muscle activation in most dogs, demonstrating that the suppression of expiratory muscle activity observed at rest persists at high levels of ventilatory drive. Other features of the rebreathing response also differed significantly from previous reports in halothane-anesthetized humans, including (1) an increase in the rib cage contribution to tidal volume during the course of rebreathing, (2) recruitment of parasternal intercostal activity by rebreathing, (3) differences in the response of ventilatory timing, and (4) the lack of effect of anesthetic depth on the slope of the ventilatory response. These marked species differences are further evidence that the dog is not a suitable model to study anesthetic effects on the activation of human respiratory muscles.

Effects of Vocal Task and Respiratory Phase on Prephonatory Chest Wall Movements

1992 ◽  
Vol 35 (5) ◽  
pp. 971-982 ◽  
Author(s):  
David H. McFarland ◽  
Anne Smith
Keyword(s):  
Reaction Time ◽  
Chest Wall ◽  
Breathing Cycle ◽  
Quiet Breathing ◽  
Respiratory Volume ◽  
Rib Cage ◽  
Reaction Time Paradigm ◽  
Vocal Responses ◽  
Respiratory Phase ◽  
Vocal Reaction Time

A vocal reaction time paradigm was used to explore prephonatory respiratory kinematics. Movements of the rib cage and abdomen were recorded prior to production of utterances differing in length and intensity, and vocal responses were elicited in different phases and volumes of the quiet breathing cycle. A velocity threshold was used to distinguish prephonatory adjustments from the cyclical movements of the chest wall that are characteristic of quiet breathing. The results suggest that a variety of prephonatory kinematic events can occur prior to initiation of vocalization in response to a stimulus. Further, prephonatory movements appear to be adaptive in that they are influenced by the length of the utterance to be spoken and the respiratory volume at the time of voice initiation.

Chest wall kinematic determinants of diaphragm length by optoelectronic plethysmography and ultrasonography

2003 ◽  
Vol 94 (2) ◽  
pp. 621-630 ◽  
Author(s):  
A. Aliverti ◽  
G. Ghidoli ◽  
R. L. Dellacà ◽  
A. Pedotti ◽  
P. T. Macklem
Keyword(s):  
Regression Analysis ◽  
Chest Wall ◽  
Linear Regression Analysis ◽  
Axial Distance ◽  
Flow Limitation ◽  
Quiet Breathing ◽  
Expiratory Flow Limitation ◽  
Rib Cage ◽  
Optoelectronic Plethysmography ◽  
Expiratory Flow

To estimate diaphragm fiber length from thoracoabdominal configuration, we measured axial motion of the right-sided area of apposition by ultrasonography and volumes displaced by chest wall compartments [pulmonary, abdominal rib cage, and abdomen (Vab)] by optoelectronic plethysmography in four normal men during quiet breathing and incremental exercise without and with expiratory flow limitation. Points at the cephalic area of apposition border were digitized from echo images and mapped into three-dimensional space, and the axial distance from the xyphoidal transverse plane (Dap) was measured simultaneously with the volumes. Linear regression analysis between changes (Δ) in Dap and the measured volume changes under all conditions showed that 1) ΔDap was linearly related more to ΔVab than to changes in pulmonary and abdominal rib cage volumes; and 2) this was highly repeatable between measures. Multiple stepwise regression analysis showed that ΔVab accounted for 89–96% of the variability of ΔDap, whereas the rib cage compartments added <1%. We conclude that, under conditions of quiet breathing and exercise, with and without expiratory flow limitation, instantaneous ΔDap can be estimated from ΔVab.

Association of chest wall motion and tidal volume responses during CO2 rebreathing

1996 ◽  
Vol 81 (4) ◽  
pp. 1528-1534 ◽  
Author(s):  
Sheng Yan ◽  
Pawel Sliwinski ◽  
Peter T. Macklem
Keyword(s):  
Tidal Volume ◽  
Chest Wall ◽  
Wall Motion ◽  
Forced Expiratory Volume ◽  
Quiet Breathing ◽  
Rib Cage ◽  
Chest Wall Motion ◽  
Variable Recruitment ◽  
The Individual ◽  
End Tidal

Yan, Sheng, Pawel Sliwinski, and Peter T. Macklem.Association of chest wall motion and tidal volume responses during CO2 rebreathing. J. Appl. Physiol. 81(4): 1528–1534, 1996.—The purpose of this study is to investigate the effect of chest wall configuration at end expiration on tidal volume (Vt) response during CO2 rebreathing. In a group of 11 healthy male subjects, the changes in end-expiratory and end-inspiratory volume of the rib cage (ΔVrc,e and ΔVrc,i, respectively) and abdomen (ΔVab,eand ΔVab,i, respectively) measured by linearized magnetometers were expressed as a function of end-tidal[Formula: see text]([Formula: see text]). The changes in end-expiratory and end-inspiratory volumes of the chest wall (ΔVcw,e and ΔVcw,i, respectively) were calculated as the sum of the respective rib cage and abdominal volumes. The magnetometer coils were placed at the level of the nipples and 1–2 cm above the umbilicus and calibrated during quiet breathing against the Vt measured from a pneumotachograph. The ΔVrc,e/[Formula: see text]slope was quite variable among subjects. It was significantly positive ( P < 0.05) in five subjects, significantly negative in four subjects ( P < 0.05), and not different from zero in the remaining two subjects. The ΔVab,e/[Formula: see text]slope was significantly negative in all subjects ( P < 0.05) with a much smaller intersubject variation, probably suggesting a relatively more uniform recruitment of abdominal expiratory muscles and a variable recruitment of rib cage muscles during CO2rebreathing in different subjects. As a group, the mean ΔVrc,e/[Formula: see text], ΔVab,e/[Formula: see text], and ΔVcw,e/[Formula: see text]slopes were 0.010 ± 0.034, −0.030 ± 0.007, and −0.020 ± 0.032 l / Torr, respectively; only the ΔVab,e/[Formula: see text]slope was significantly different from zero. More interestingly, the individual ΔVt/[Formula: see text]slope was negatively associated with the ΔVrc,e/[Formula: see text]( r = −0.68, P = 0.021) and ΔVcw,e/[Formula: see text]slopes ( r = −0.63, P = 0.037) but was not associated with the ΔVab,e/[Formula: see text]slope ( r = 0.40, P = 0.223). There was no correlation of the ΔVrc,e/[Formula: see text]and ΔVcw,e/[Formula: see text]slopes with age, body size, forced expiratory volume in 1 s, or expiratory time. The group ΔVab,i/[Formula: see text]slope (0.004 ± 0.014 l / Torr) was not significantly different from zero despite the Vt nearly being tripled at the end of CO2 rebreathing. In conclusion, the individual Vtresponse to CO2, although independent of ΔVab,e, is a function of ΔVrc,e to the extent that as the ΔVrc,e/[Formula: see text]slope increases (more positive) among subjects, the Vt response to CO2 decreases. These results may be explained on the basis of the respiratory muscle actions and interactions on the rib cage.

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.

Relative contributions of the rib cage and the diaphragm to ventilation in man

1964 ◽  
Vol 19 (4) ◽  
pp. 698-706 ◽  
Author(s):  
Edward H. Bergofsky
Keyword(s):  
Tidal Volume ◽  
Work Of Breathing ◽  
Normal Subjects ◽  
Gas Mixtures ◽  
Abdominal Pressure ◽  
Rib Cage ◽  
Pressure Changes ◽  
Work Done

A plethysmographic method was used to partition the tidal volume into two components: that due to rib-cage expansion and that due to diaphragmatic descent. In 15 normal subjects, one-third of the tidal volume was effected by diaphragmatic descent during various situations, i.e., at rest, voluntary respiratory maneuvers, and breathing special gas mixtures. This technic was combined with measurements of intra-abdominal pressure changes in order to measure the extrapulmonary work done by the diaphragm. For ordinary breathing, this work was found to equal the total extrapulmonary work of breathing (rib cage plus diaphragm) measured by passive ventilation in a body respirator, indicating that the rib cage requires no work to move itself until tidal volumes greater than 1 liter are reached. thorax; work of breathing Submitted on October 24, 1963

The effect of estimating chest wall compliance on the work of breathing during exercise as determined via the modified Campbell diagram

2020 ◽  
Author(s):  
Elizabeth A. Gideon ◽  
Troy J. Cross ◽  
Catherine L. Coriell ◽  
Joseph W. Duke
Keyword(s):  
Chest Wall ◽  
Work Of Breathing ◽  
Cycle Ergometer ◽  
Campbell Diagram ◽  
Chest Wall Compliance ◽  
A Value ◽  
Graded Exercise ◽  
Prior Literature ◽  
Wall Compliance

The modified Campbell diagram provides one of the most comprehensive assessments of the work of breathing (Wb) during exercise, wherein the resistive and elastic work of inspiration and expiration are quantified. Importantly, a necessary step in constructing the modified Campbell diagram is to obtain a value for chest wall compliance (CCW). To date, it remains unknown whether estimating or directly measuring CCW impacts on the Wb as determined by the modified Campbell diagram. Therefore, the purpose of this study was to evaluate whether the components of the Wb differ when the modified Campbell diagram is constructed using an estimated versus measured value of CCW. Forty-two participants (n = 26 men, 16 women) performed graded exercise to volitional exhaustion on a cycle ergometer. CCW was measured directly at rest via quasi-static relaxation. Estimated values of CCW were taken from prior literature. The measured value of CCW was greater than that obtained via estimation (214 ± 52 mL∙cmH2O-1 vs. 189 ± 18 mL∙cmH2O-1, p < 0.05). At modest to high minute ventilations (i.e., 50-200 L∙min-1), the inspiratory elastic Wb was greater, and expiratory resistive Wb was lower, when modified Campbell diagrams were constructed using estimated compared with measured values of CCW (p < 0.05). These differences were however small, and never exceeded ±5%. Thus, although our findings demonstrate that estimating CCW has a measurable impact on the determination of the Wb, its effect appears relatively small within a cohort of healthy adults during graded exercise.

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