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.

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

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

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.

μ-Opioid receptor agonist effects on medullary respiratory neurons in the cat: evidence for involvement in certain types of ventilatory disturbances

2003 ◽  
Vol 285 (6) ◽  
pp. R1287-R1304 ◽  
Author(s):  
Peter M. Lalley
Keyword(s):  
Tidal Volume ◽  
Chest Wall ◽  
Opioid Receptor ◽  
Membrane Properties ◽  
Respiratory Neurons ◽  
Opioid Agonist ◽  
Chest Wall Compliance ◽  
Wall Compliance ◽  
Μ Opioid Receptor ◽  
Synaptic Drive

μ-Opioid receptor agonists depress tidal volume, decrease chest wall compliance, and increase upper airway resistance. In this study, potential neuronal sites and mechanisms responsible for the disturbances were investigated, dose-response relationships were established, and it was determined whether general anesthesia plays a role. Effects of μ-opioid agonists on membrane properties and discharges of respiratory bulbospinal, vagal, and propriobulbar neurons and phrenic nerve activity were measured in pentobarbital-anesthetized and unanesthetized decerebrate cats. In all types of respiratory neurons tested, threshold intravenous doses of the μ-opioid agonist fentanyl slowed discharge frequency and prolonged duration without altering peak discharge intensity. Larger doses postsynaptically depressed discharges of inspiratory bulbospinal and inspiratory propriobulbar neurons that might account for depression of tidal volume. Iontophoresis of the μ-opioid agonist DAMGO also depressed the intensity of inspiratory bulbospinal neuron discharges. Fentanyl given intravenously prolonged discharges leading to tonic firing of bulbospinal expiratory neurons in association with reduced hyperpolarizing synaptic drive potentials, perhaps explaining decreased inspiratory phase chest wall compliance. Lowest effective doses of fentanyl had similar effects on vagal postinspiratory (laryngeal adductor) motoneurons, whereas in vagal laryngeal abductor and pharyngeal constrictor motoneurons, depression of depolarizing synaptic drive potentials led to sparse, very-low-frequency discharges. Such effects on three types of vagal motoneurons might explain tonic vocal fold closure and pharyngeal obstruction of airflow. Measurements of membrane potential and input resistance suggest the effects on bulbospinal Aug-E neurons and vagal motoneurons are mediated presynaptically. Opioid effects on the respiratory neurons were similar in anesthetized and decerebrate preparations.

A comparison of methods used to quantify the work of breathing during exercise

2021 ◽  
Author(s):  
Troy James Cross ◽  
Elizabeth A. Gideon ◽  
Sarah J. Morris ◽  
Catherine L. Coriell ◽  
Colin D. Hubbard ◽  
...  
Keyword(s):  
Gold Standard ◽  
Respiratory Mechanics ◽  
Work Of Breathing ◽  
Specific Method ◽  
Campbell Diagram ◽  
Volitional Exhaustion ◽  
Volume Integration ◽  
Graded Exercise ◽  
Systematic Pattern ◽  
No Gold Standard

The mechanical work of breathing (Wb) is an insightful tool used to assess respiratory mechanics during exercise. There are several different methods used to calculate the Wb, however - each approach having its own distinct advantages/disadvantages. To date, a comprehensive assessment of the differences in the components of Wb between these methods is lacking. We therefore sought to compare the values of Wb during graded exercise as determined via the 4 most popular methods: (i) pressure-volume integration; (ii) the Hedstrand diagram; (iii) the Otis diagram; and the (iv) modified Campbell diagram. Forty-two participants (30 ± 15 years; 16 women) performed graded cycling to volitional exhaustion. Oesophageal pressure-volume loops were obtained throughout exercise. These data were used to calculate the total Wb and, where possible, its subcomponents of inspiratory and expiratory, resistive and elastic Wb, using each of the 4 methods. Our results demonstrate that the components of Wb were indeed different between methods across the minute ventilations engendered by graded exercise (P < 0.05). Importantly, however, no systematic pattern in these differences could be observed. Our findings indicate that the values of Wb obtained during exercise are uniquely determined by the specific method chosen to compute its value - no two methods yield identical results. Because there is currently no "gold-standard" for measuring the Wb, it is emphasized that future investigators be cognizant of the limitations incurred by their chosen method, such that observations made by others may be interpreted with greater context, and transparency.

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