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

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%.

Chest wall and trunk muscle activity during inspiratory loading

1992 ◽  
Vol 73 (6) ◽  
pp. 2373-2381 ◽  
Author(s):  
S. J. Cala ◽  
J. Edyvean ◽  
L. A. Engel
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Normal Subjects ◽  
Systematic Difference ◽  
Erector Spinae ◽  
Inspiratory Pressure ◽  
Emg Activity ◽  
Consistent Difference ◽  
Lung Volumes ◽  
Resistive Loading

We measured the electromyographic (EMG) activity in four chest wall and trunk (CWT) muscles, the erector spinae, latissimus dorsi, pectoralis major, and trapezius, together with the parasternal, in four normal subjects during graded inspiratory efforts against an occlusion in both upright and seated postures. We also measured CWT EMGs in six seated subjects during inspiratory resistive loading at high and low tidal volumes [1,280 +/- 80 (SE) and 920 +/- 60 ml, respectively]. With one exception, CWT EMG increased as a function of inspiratory pressure generated (Pmus) at all lung volumes in both postures, with no systematic difference in recruitment between CWT and parasternal muscles as a function of Pmus. At any given lung volume there was no consistent difference in CWT EMG at a given Pmus between the two postures (P > 0.09). However, at a given Pmus during both graded inspiratory efforts and inspiratory resistive loading, EMGs of all muscles increased with lung volume, with greater volume dependence in the upright posture (P < 0.02). The results suggest that during inspiratory efforts, CWT muscles contribute to the generation of inspiratory pressure. The CWT muscles may act as fixators opposing deflationary forces transmitted to the vertebral column by rib cage articulations, a function that may be less effective at high lung volumes if the direction of the muscular insertions is altered disadvantageously.

scholarly journals Respiratory dynamics during laughter

2001 ◽  
Vol 90 (4) ◽  
pp. 1441-1446 ◽  
Author(s):  
Mario Filippelli ◽  
Riccardo Pellegrino ◽  
Iacopo Iandelli ◽  
Gianni Misuri ◽  
Joseph R. Rodarte ◽  
...  
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Dynamic Compression ◽  
Three Dimensional ◽  
Normal Subjects ◽  
Average Frequency ◽  
Abdominal Pressure ◽  
Sudden Increase ◽  
Lung Volumes ◽  
Transdiaphragmatic Pressure

Lung and chest wall mechanics were studied during fits of laughter in 11 normal subjects. Laughing was naturally induced by showing clips of the funniest scenes from a movie by Roberto Benigni. Chest wall volume was measured by using a three-dimensional optoelectronic plethysmography and was partitioned into upper thorax, lower thorax, and abdominal compartments. Esophageal (Pes) and gastric (Pga) pressures were measured in seven subjects. All fits of laughter were characterized by a sudden occurrence of repetitive expiratory efforts at an average frequency of 4.6 ± 1.1 Hz, which led to a final drop in functional residual capacity (FRC) by 1.55 ± 0.40 liter ( P < 0.001). All compartments similarly contributed to the decrease of lung volumes. The average duration of the fits of laughter was 3.7 ± 2.2 s. Most of the events were associated with sudden increase in Pes well beyond the critical pressure necessary to generate maximum expiratory flow at a given lung volume. Pga increased more than Pes at the end of the expiratory efforts by an average of 27 ± 7 cmH2O. Transdiaphragmatic pressure (Pdi) at FRC and at 10% and 20% control forced vital capacity below FRC was significantly higher than Pdi at the same absolute lung volumes during a relaxed maneuver at rest ( P < 0.001). We conclude that fits of laughter consistently lead to sudden and substantial decrease in lung volume in all respiratory compartments and remarkable dynamic compression of the airways. Further mechanical stress would have applied to all the organs located in the thoracic cavity if the diaphragm had not actively prevented part of the increase in abdominal pressure from being transmitted to the chest wall cavity.

scholarly journals Mechanical Ventilation Guided by Uncalibrated Esophageal Pressure May Be Potentially Harmful

2020 ◽  
Vol 133 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Gianmaria Cammarota ◽  
Gianluigi Lauro ◽  
Erminio Santangelo ◽  
Ilaria Sguazzotti ◽  
Raffaella Perucca ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Robotic Surgery ◽  
Chest Wall ◽  
Clinical Setting ◽  
Intrathoracic Pressure ◽  
Esophageal Pressure ◽  
Esophageal Balloon ◽  
Manufacturer Recommendation ◽  
Pressure Swing ◽  
The Impact

Background Esophageal balloon calibration was proposed in acute respiratory failure patients to improve esophageal pressure assessment. In a clinical setting characterized by a high variability of abdominal load and intrathoracic pressure (i.e., pelvic robotic surgery), the authors hypothesized that esophageal balloon calibration could improve esophageal pressure measurements. Accordingly, the authors assessed the impact of esophageal balloon calibration compared to conventional uncalibrated approach during pelvic robotic surgery. Methods In 30 adult patients, scheduled for elective pelvic robotic surgery, calibrated end-expiratory and end-inspiratory esophageal pressure, and the associated respiratory variations were obtained at baseline, after pneumoperitoneum–Trendelenburg application, and with positive end-expiratory pressure (PEEP) administration and compared to uncalibrated values measured at 4-ml filling volume, as per manufacturer recommendation. Data are expressed as median and [25th, 75th percentile]. Results Ninety calibrations were successfully performed. Chest wall elastance worsened with pneumoperitoneum–Trendelenburg and PEEP (19.0 [15.5, 24.6] and 16.7 [11.4, 21.7] cm H2O/l) compared to baseline (8.8 [6.3, 9.8] cm H2O/l; P &lt; 0.0001 for both comparisons). End-expiratory and end-inspiratory calibrated esophageal pressure progressively increased from baseline (3.7 [2.2, 6.0] and 7.7 [5.9, 10.2] cm H2O) to pneumoperitoneum–Trendelenburg (6.2 [3.8, 10.2] and 16.1 [13.1, 20.6] cm H2O; P = 0.014 and P &lt; 0.001) and PEEP (8.8 [7.7, 15.6] and 18.9 [16.3, 22.0] cm H2O; P &lt; 0.0001 vs. baseline for both comparison; P &lt; 0.001 and P = 0.002 vs. pneumoperitoneum–Trendelenburg) and, at each study step, they were persistently lower than uncalibrated esophageal pressure (P &lt; 0.0001 for all comparisons). Overall, difference among uncalibrated and calibrated esophageal pressure was 5.1 [3.8, 8.4] cm H2O at end-expiration and 3.8 [3.0, 6.3] cm H2O at end-inspiration. Uncalibrated esophageal pressure swing was always lower than calibrated one (P &lt; 0.0001 for all comparisons) with a difference of −1.0 [−1.8, −0.4] cm H2O. Conclusions In a clinical setting with variable chest wall mechanics, uncalibrated measurements substantially overestimated absolute values and underestimated respiratory variations of esophageal pressure. Calibration could substantially improve mechanical ventilation guided by esophageal pressure. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Acute effects of thixotropy conditioning of inspiratory muscles on end-expiratory chest wall and lung volumes in normal humans

2006 ◽  
Vol 101 (1) ◽  
pp. 298-306 ◽  
Author(s):  
Masahiko Izumizaki ◽  
Michiko Iwase ◽  
Yasuyoshi Ohshima ◽  
Ikuo Homma
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Human Subjects ◽  
Esophageal Pressure ◽  
Acute Effects ◽  
Lung Volumes ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Normal Human ◽  
Inflated Lung

Thixotropy conditioning of inspiratory muscles consisting of maximal inspiratory effort performed at an inflated lung volume is followed by an increase in end-expiratory position of the rib cage in normal human subjects. When performed at a deflated lung volume, conditioning is followed by a reduction in end-expiratory position. The present study was performed to determine whether changes in end-expiratory chest wall and lung volumes occur after thixotropy conditioning. We first examined the acute effects of conditioning on chest wall volume during subsequent five-breath cycles using respiratory inductive plethysmography ( n = 8). End-expiratory chest wall volume increased after conditioning at an inflated lung volume ( P < 0.05), which was attained mainly by rib cage movements. Conditioning at a deflated lung volume was followed by reductions in end-expiratory chest wall volume, which was explained by rib cage and abdominal volume changes ( P < 0.05). End-expiratory esophageal pressure decreased and increased after conditioning at inflated and deflated lung volumes, respectively ( n = 3). These changes in end-expiratory volumes and esophageal pressure were greatest for the first breath after conditioning. We also found that an increase in spirometrically determined inspiratory capacity ( n = 13) was maintained for 3 min after conditioning at a deflated lung volume, and a decrease for 1 min after conditioning at an inflated lung volume. Helium-dilution end-expiratory lung volume increased and decreased after conditioning at inflated and deflated lung volumes, respectively (both P < 0.05; n = 11). These results suggest that thixotropy conditioning changes end-expiratory volume of the chest wall and lung in normal human subjects.

scholarly journals STUDIES OF LUNG VOLUME

1918 ◽  
Vol 27 (1) ◽  
pp. 87-94 ◽  
Author(s):  
A. Garvin ◽  
Christen Lundsgaard ◽  
Donald D. Van Slyke
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Vital Capacity ◽  
Normal Lung ◽  
Lung Volumes ◽  
Total Lung Volume ◽  
Normal Limits ◽  
Male Patients ◽  
Total Capacity ◽  
Residual Air

1. The total capacity, middle capacity, and residual air have been determined in 31 adult male patients suffering from tuberculosis of the lungs. 2. The chest volumes have been determined in each case and the normal lung volumes calculated by means of the ratios worked out in a previous paper. 3. In nine patients with incipient tuberculosis, the total lung volume was found within normal limits, whereas the vital capacity was diminished as a result of an increased residual air. The increase in the residual air was due to less complete expiration, caused partly by diminished movement of the diaphragm, partly by diminished compression of the chest wall. The diminished movement of the diaphragm was, as a rule, most marked on the most affected side. Whether these decreased movements are due to a reflex or to stiffness of the lung tissue we could not determine. The middle capacity was found practically normal. 4. In twenty-two cases of moderately advanced, and advanced tuberculosis, the total lung volume was in most cases markedly decreased. The vital capacity was substantially decreased, principally as a result of the diminished total capacity. The residual air was, as a rule, normal, although in a few cases an increase in residual air also contributed to the decrease in the vital capacity. The middle capacity, on which we do not want to put too much stress, was normal in some patients and considerably diminished in others.

scholarly journals Impact of lung volume changes on perfusion estimates derived by Electrical Impedance Tomography

2019 ◽  
Vol 5 (1) ◽  
pp. 199-202
Author(s):  
Sabine Krueger-Ziolek ◽  
Bo Gong ◽  
Bernhard Laufer ◽  
Knut Moeller
Keyword(s):  
Observational Study ◽  
Electrical Impedance Tomography ◽  
Lung Volume ◽  
Electrical Impedance ◽  
Region Of Interest ◽  
Intrathoracic Pressure ◽  
Breath Holding ◽  
Impedance Tomography ◽  
Lung Volumes ◽  
The Impact

AbstractElectrical Impedance Tomography (EIT), an imaging technique which operates non-invasively and without radiation exposure, provides information about ventilation- and cardiac-synchronous (pulsatile) changes in the lung. It is well known, that perfusion within the thorax is influenced by lung volume or intrathoracic pressure. In this observational study, it shall be investigated if this phenomenon can be monitored by EIT. Therefore, the impact of the amount of air within the lung on the pulsatile EIT signal was evaluated by carrying out EIT measurements with a spontaneously breathing lung healthy subject holding the breath at three different inspiratory and three various expiratory volume levels during normal tidal breathing. For EIT data analysis, a region of interest was defined by including lung tissue and excluding the heart region. The EIT data revealed, that the shape and the amplitude of the pulsatile EIT signal (evaluated per heartbeat) during the phases of breath holding were dependent on the enclosed lung volume. For lung volumes > 4 L, the amplitude of the pulsatile EIT signal increased with rising inspiratory level and the shape remained almost unchanged. For lung volumes < 4 L, a change in shape was visible but the amplitude remained more or less the same with decreasing expiratory level. Since the results of this observational study show that the pulsatile EIT signal is influenced by the lung volume, it might be used in future to draw conclusions of cardiacpulmonary interactions or intrathoracic pressure states, benefitting the treatment of intensive care patients.

Partitioning the work of breathing during running and cycling using optoelectronic plethysmography

2021 ◽  
Author(s):  
Shalaya Kipp ◽  
Michael G. Leahy ◽  
Jacob A. Hanna ◽  
Andrew William Sheel
Keyword(s):  
Maximal Exercise ◽  
Work Of Breathing ◽  
Respiratory Muscles ◽  
Quantitative Measure ◽  
Mechanical Work ◽  
Abdominal Muscles ◽  
Relative Contribution ◽  
Balloon Catheters ◽  
Optoelectronic Plethysmography ◽  
Work Done

Work of breathing (Wb) derived from a single lung volume and pleural pressure is limited and does not fully characterize the mechanical work done by the respiratory musculature. It has long been known abdominal activation increases with increasing exercise intensity, yet the mechanical work done by these muscles is not reflected in Wb. Using Optoelectronic plethysmography (OEP) we sought to show first, the volumes obtained from OEP (VCW) were comparable to volumes obtained from flow integration (Vt) during cycling and running, and second, to show partitioned volume from OEP could be utilized to quantify the mechanical work done by the ribcage (WBRC) and abdomen (WBAB) during exercise. We fit 11 subjects (6 males/ 5 females) with reflective markers and balloon catheters. Subjects completed an incremental ramp cycling test to exhaustion and a series of submaximal running trials. We found good agreement between VCW vs Vt during cycling (p>0.05) and running (p>0.05). From rest to maximal-exercise, WBAB increased by 84% (range: 30 - 99%;WBAB: 1 ± 1 J/min to 61 ± 52 J/min). The relative contribution of the abdomen increased from 17 ± 9% at rest to 26 ± 16% during maximal-exercise. Our study highlights and provides a quantitative measure of the role of the abdominal muscles during exercise. Incorporating the work done by the abdomen allows for a greater understanding of the mechanical tasks required by the respiratory muscles and could provide further insight into how the respiratory system functions during disease and injury.

Motion of the Rib Cage and the Abdomen in Tetraplegic Patients

1978 ◽  
Vol 54 (1) ◽  
pp. 25-32 ◽  
Author(s):  
J. P. Mortola ◽  
G. Sant' Ambrogio
Keyword(s):  
Chest Wall ◽  
Cervical Spinal Cord ◽  
Work Of Breathing ◽  
Intrathoracic Pressure ◽  
Normal Subjects ◽  
Flow Profile ◽  
Rib Cage ◽  
Sitting Posture ◽  
Supine Posture ◽  
High Work

1. We have studied the motion of the abdomen and the rib cage in patients with a transection of the lower cervical spinal cord during normal breathing both in the supine and sitting posture, and compared it with that of normal subjects. 2. In the supine posture the rib cage of a patient moves paradoxically inward, therefore his chest wall is deformed, which explains the high work of breathing. 3. During expiration, beside the recoil of the respiratory system, there is also the recoil of the deformed chest wall, toward its passive configuration, with an expansion of the rib cage above its resting position during the first part of expiration and an alteration of the expiratory flow profile. 4. In a sitting ‘relaxed’ posture the paradoxical inward motion disappears in the lower rib cage, and it is reduced but still present in the higher rib cage. 5. We conclude that contraction of the diaphragm constricts the ‘passive rib cage’, either directly through its insertions or indirectly through the reduction of intrathoracic pressure. In seated subjects the diaphragm causes some expansion of the rib cage at its lower level. Therefore the motion of the rib cage is not only related to the balance between the forces developed by the diaphragm and the intercostal muscles, but also to the diaphragm dome configuration, the geometry of the rib cage and the lung volume.

Methacholine-induced bronchoconstriction in dogs: effects of lung volume and O3 exposure

1988 ◽  
Vol 65 (6) ◽  
pp. 2679-2686 ◽  
Author(s):  
S. T. Kariya ◽  
S. A. Shore ◽  
W. A. Skornik ◽  
K. Anderson ◽  
R. H. Ingram ◽  
...  
Keyword(s):  
Lung Volume ◽  
Maximal Response ◽  
Maximal Effect ◽  
Response Curves ◽  
Lung Volumes ◽  
Before And After ◽  
Residual Capacity ◽  
Induced Changes ◽  
Conducting Airways ◽  
Concentration Response Curve

The maximal effect induced by methacholine (MCh) aerosols on pulmonary resistance (RL), and the effects of altering lung volume and O3 exposure on these induced changes in RL, was studied in five anesthetized and paralyzed dogs. RL was measured at functional residual capacity (FRC), and lung volumes above and below FRC, after exposure to MCh aerosols generated from solutions of 0.1-300 mg MCh/ml. The relative site of response was examined by magnifying parenchymal [RL with large tidal volume (VT) at fast frequency (RLLS)] or airway effects [RL with small VT at fast frequency (RLSF)]. Measurements were performed on dogs before and after 2 h of exposure to 3 ppm O3. MCh concentration-response curves for both RLLS and RLSF were sigmoid shaped. Alterations in mean lung volume did not alter RLLS; however, RLSF was larger below FRC than at higher lung volumes. Although O3 exposure resulted in small leftward shifts of the concentration-response curve for RLLS, the airway dominated index of RL (RLSF) was not altered by O3 exposure, nor was the maximal response using either index of RL. These data suggest O3 exposure does not affect MCh responses in conducting airways; rather, it affects responses of peripheral contractile elements to MCh, without changing their maximal response.

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