Effect of regional chest wall restriction on regional lung function

1980 ◽  
Vol 49 (4) ◽  
pp. 655-662 ◽  
Author(s):  
L. Forkert
Keyword(s):  
Lung Function ◽  
Normal Distribution ◽  
Chest Wall ◽  
Functional Residual Capacity ◽  
Scintillation Detectors ◽  
Rib Cage ◽  
Regional Lung Function ◽  
Regional Lung ◽  
Midaxillary Line ◽  
Residual Capacity

The effect of impeding regional chest wall excursion on regional lung function was assessed. Fourteen subjects were studied while seated in a volume-displacement plethysmography. The lower rib cage and epigastrium were restricted with an inextensible binder. Because such restriction increases lung recoil and diminishes functional residual capacity (FRC), all measurements were made at the unstrapped FRC (FRCus). Regional excursion of the chest wall was measured with magnetometers placed anteroposteriorly at the sternomanubrial angle, the xyphoid, and umbilicus and transversely at the level of the xyphoid at the midaxillary line. Regional lung function was assessed by measuring the distribution of inspired boluses and washout of 133Xe with scintillation detectors positioned against the subject's back at the apical, middle, and basal regions. Restriction of the lower chest wall impeded expansion of the lower rib cage and diminished the distribution of inspired gas to and washout of the lung bases. The upper rib cage expanded normally and was associated with an increased distribution of inspired gas and normal distribution of washout to the apices. These results suggest that regional lung function was dependent on regional rib cage excursion.

Effect of acceleration on the chest wall

1994 ◽  
Vol 76 (3) ◽  
pp. 1242-1246 ◽  
Author(s):  
T. A. Wilson ◽  
S. Liu
Keyword(s):  
Experimental Study ◽  
Chest Wall ◽  
Functional Residual Capacity ◽  
Lung Volume ◽  
Airway Pressure ◽  
Gravitational Force ◽  
Respiratory Effect ◽  
Rib Cage ◽  
Modeling And Analysis ◽  
Residual Capacity

The gravitational force on the rib cage has been found to be an expiratory force of approximately 8 cmH2O. The gravitational force on the abdomen is an inspiratory force of the same magnitude. Because the compliance of the rib cage is greater than the compliance of the abdomen, it follows that gravity has a net expiratory effect on lung volume and that upward accelerations augmenting the gravitational force would have an additional expiratory effect. This conclusion is contrary to observations that functional residual capacity increases during headward accelerations in centrifuges and during intervals of upward acceleration in airplanes. We report the results of two studies of the effects of accelerations that are smaller in magnitude and of shorter duration than those studied in centrifuges and airplanes. The first was an experimental study of the effect of acceleration in an elevator. In subjects who relaxed against an occluded airway, airway pressure increased during upward accelerations and decreased during downward accelerations. The second was the modeling and analysis of the effects of the accelerations that occur during walking. The analysis predicted an initial expiratory response to the acceleration spike that occurs during footfall. The prediction agreed with data in the literature on the respiratory effect of walking. In both of these studies upward accelerations had an expiratory effect.

Chest wall mechanics in sustained microgravity

1998 ◽  
Vol 84 (6) ◽  
pp. 2060-2065 ◽  
Author(s):  
Muriel Wantier ◽  
Marc Estenne ◽  
Sylvia Verbanck ◽  
G. Kim Prisk ◽  
Manuel Paiva
Keyword(s):  
Tidal Volume ◽  
Chest Wall ◽  
Functional Residual Capacity ◽  
Postural Change ◽  
Rib Cage ◽  
Chest Wall Mechanics ◽  
Supine Posture ◽  
Abdominal Compliance ◽  
Residual Capacity ◽  
Measured Flow

We assessed the effects of sustained weightlessness on chest wall mechanics in five astronauts who were studied before, during, and after the 10-day Spacelab D-2 mission ( n = 3) and the 180-day Euromir-95 mission ( n= 2). We measured flow and pressure at the mouth and rib cage and abdominal volumes during resting breathing and during a relaxation maneuver from midinspiratory capacity to functional residual capacity. Microgravity produced marked and consistent changes (Δ) in the contribution of the abdomen to tidal volume [ΔVab/(ΔVab + ΔVrc), where Vab is abdominal volume and Vrc is rib cage volume], which increased from 30.7 ± 3.5 (SE)% at 1 G head-to-foot acceleration to 58.3 ± 5.7% at 0 G head-to-foot acceleration ( P < 0.005). Values of ΔVab/(ΔVab + ΔVrc) did not change significantly during the 180 days of the Euromir mission, but in the two subjects ΔVab/(ΔVab + ΔVrc) was greater on postflight day 1 than on subsequent postflight days or preflight. In the two subjects who produced satisfactory relaxation maneuvers, the slope of the Konno-Mead plot decreased in microgravity; this decrease was entirely accounted for by an increase in abdominal compliance because rib cage compliance did not change. These alterations are similar to those previously reported during short periods of weightlessness inside aircrafts flying parabolic trajectories. They are also qualitatively similar to those observed on going from upright to supine posture; however, in contrast to microgravity, such postural change reduces rib cage compliance.

Human Chest Wall Function during Epidural Anesthesia

1996 ◽  
Vol 85 (4) ◽  
pp. 761-773 ◽  
Author(s):  
David O. Warner ◽  
Mark A. Warner ◽  
Erik L. Ritman
Keyword(s):  
Chest Wall ◽  
Functional Residual Capacity ◽  
Muscle Activity ◽  
Respiratory Muscle ◽  
Sensory Level ◽  
Wall Function ◽  
Rib Cage ◽  
Residual Capacity ◽  
The Mean ◽  
Respiratory Muscle Activity

Background Although epidural anesthesia (EA) can significantly disrupt the function of the respiratory system, data concerning its effects on respiratory muscle activity and the resulting motion of the chest wall are scarce. This study aimed to determine the effects of lumbar EA on human chest wall function during quiet breathing. Methods Six persons were studied while awake and during mid-thoracic (approximately a T6 sensory level) and high (approximately a T1 sensory level) lumbar EA produced by either 2% lidocaine (two persons) or 1.5% etidocaine (four persons) with 1:200,000 epinephrine. Respiratory muscle activity was measured using fine-wire electromyography electrodes. Chest wall configuration during high EA was determined using images of the thorax obtained by three-dimensional, fast computed tomography. The functional residual capacity was measured using a nitrogen dilution technique. Results High EA abolished activity in the parasternal intercostal muscles of every participant but one, whereas the mean phasic activity of the scalene muscles was unchanged. High EA significantly decreased the inspiratory volume displacement of the rib cage compared with intact breathing but did not have a significant effect on diaphragm displacement. Therefore, high EA decreased the percentage contribution of rib cage expansion to inspiratory increases in thoracic volume (delta Vth) (from 27 +/- 2 [MSE] to 10 +/- 11% of delta Vth). Paradoxic rib cage motion during inspiration (i.e., a net inward motion during inspiration) developed in only one participant. High EA substantially increased the functional residual capacity (by 295 +/- 89 ml), with a significant net caudad motion of the end expiratory position of the diaphragm. In addition, high EA significantly decreased the volume of liquid in the thorax at end expiration in five of the six participants, a factor that also contributed to the increase in functional residual capacity in these persons. Conclusions Rib cage expansion continues to contribute to tidal volume during high EA in most subjects, even when most of the muscles of the rib cage are paralyzed; the mean phasic electrical activity of unblocked respiratory muscles such as scalenes does not increase in response to rib cage muscle paralysis produced by EA; and high EA increases the functional residual capacity, an increase produced in most participants by a caudad motion of the diaphragm and a decrease in intrathoracic blood volume.

scholarly journals FIRST-IN-HUMAN VALIDATION OF X-RAY VELOCIMETRY DEMONSTRATES SUPERIOR SENSITIVITY OVER SPIROMETRY AND CT FOR QUANTIFICATION OF REGIONAL LUNG FUNCTION

CHEST Journal ◽  
2020 ◽  
Vol 158 (4) ◽  
pp. A1393-A1394
Author(s):  
Jonathan Dusting ◽  
Olivia Stephens ◽  
David Wenger ◽  
Chandni Doshi ◽  
John DeMarco ◽  
...  
Keyword(s):  
Lung Function ◽  
X Ray ◽  
Regional Lung Function ◽  
Regional Lung ◽  
Human Validation

Abdominal distension alters regional pleural pressures and chest wall mechanics in pigs in vivo

1991 ◽  
Vol 70 (6) ◽  
pp. 2611-2618 ◽  
Author(s):  
T. Mutoh ◽  
W. J. Lamm ◽  
L. J. Embree ◽  
J. Hildebrandt ◽  
R. K. Albert
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Functional Residual Capacity ◽  
Total Lung Capacity ◽  
Abdominal Cavity ◽  
Abdominal Distension ◽  
Abdominal Pressure ◽  
Lung Capacity ◽  
Lung Expansion ◽  
Residual Capacity

Abdominal distension (AD) occurs in pregnancy and is also commonly seen in patients with ascites from various causes. Because the abdomen forms part of the "chest wall," the purpose of this study was to clarify the effects of AD on ventilatory mechanics. Airway pressure, four (vertical) regional pleural pressures, and abdominal pressure were measured in five anesthetized, paralyzed, and ventilated upright pigs. The effects of AD on the lung and chest wall were studied by inflating a liquid-filled balloon placed in the abdominal cavity. Respiratory system, chest wall, and lung pressure-volume (PV) relationships were measured on deflation from total lung capacity to residual volume, as well as in the tidal breathing range, before and 15 min after abdominal pressure was raised. Increasing abdominal pressure from 3 to 15 cmH2O decreased total lung capacity and functional residual capacity by approximately 40% and shifted the respiratory system and chest wall PV curves downward and to the right. Much smaller downward shifts in lung deflation curves were seen, with no change in the transdiaphragmatic PV relationship. All regional pleural pressures increased (became less negative) and, in the dependent region, approached 0 cmH2O at functional residual capacity. Tidal compliances of the respiratory system, chest wall, and lung were decreased 43, 42, and 48%, respectively. AD markedly alters respiratory system mechanics primarily by "stiffening" the diaphragm/abdomen part of the chest wall and secondarily by restricting lung expansion, thus shifting the lung PV curve as seen after chest strapping. The less negative pleural pressures in the dependent lung regions suggest that nonuniformities of ventilation could also be accentuated and gas exchange impaired by AD.

scholarly journals Use of Radioactive Xenon for Studies of Regional Lung Function

BMJ ◽  
1962 ◽  
Vol 2 (5311) ◽  
pp. 1006-1016 ◽  
Author(s):  
C. T. Dollery ◽  
P. Hugh-Jones ◽  
C. M. E. Matthews
Keyword(s):  
Lung Function ◽  
Regional Lung Function ◽  
Regional Lung ◽  
Radioactive Xenon
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