Thoracoabdominal mechanics during relaxed and forced vital capacity

1979 ◽  
Vol 47 (1) ◽  
pp. 38-42 ◽  
Author(s):  
N. M. Siafakas ◽  
A. J. Morris ◽  
M. Green
Keyword(s):  
Chest Wall ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
High Volume ◽  
The Other ◽  
Costal Margin ◽  
Forced Expiration ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Relaxation Characteristics

Thoracoabdominal configuration, intrathoracic (esophageal), intra-abdominal (gastric), and transdiaphragmatic pressures were studied in six normal upright subjects during relaxed (RVC) and forced vital capacity (FVC). Chest wall configuration showed substantial departure from its relaxation characteristics during FVC. Paradoxical (outward) movement was recorded for a low lateral diameter of the rib cage (on the costal margin) at high volume during RVC and during most of FVC, while the other rib cage dimensions were decreasing. Transdiaphragmatic pressure was positive during most of the FVC, particularly toward RV, reflecting active contraction of the diaphragm. We conclude that diaphragmatic activity modulates forced expiration and that the chest wall may influence the FVC maneuver.

Chest wall muscle atrophy as a contributory factor for forced vital capacity decline in systemic sclerosis-associated interstitial lung disease

Rheumatology ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 250-255
Author(s):  
Takashi Nawata ◽  
Yuichiro Shirai ◽  
Mikito Suzuki ◽  
Masataka Kuwana
Keyword(s):  
Interstitial Lung Disease ◽  
Lung Disease ◽  
Chest Wall ◽  
Muscle Atrophy ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Pulmonary Function Tests ◽  
Potential Contribution ◽  
Muscle Area ◽  
Chest Wall Muscle

Abstract Objective To investigate the potential contribution of accessory respiratory muscle atrophy to the decline of forced vital capacity (FVC) in patients with SSc-associated interstitial lung disease (ILD). Methods This single-centre, retrospective study enrolled 36 patients with SSc-ILD who underwent serial pulmonary function tests and chest high-resolution CT (HRCT) simultaneously at an interval of 1–3 years. The total extent of ILD and chest wall muscle area at the level of the ninth thoracic vertebra on CT images were evaluated by two independent evaluators blinded to the patient information. Changes in the FVC, ILD extent, and chest wall muscle area between the two measurements were assessed in terms of their correlations. Multiple regression analysis was conducted to identify the independent contributors to FVC decline. Results Interval changes in FVC and total ILD extent were variable among patients, whereas chest wall muscle area decreased significantly with time (P=0.0008). The FVC change was negatively correlated with the change in ILD extent (r=−0.48, P=0.003) and was positively correlated with the change in the chest wall muscle area (r = 0.53, P=0.001). Multivariate analysis revealed that changes in total ILD extent and chest wall muscle area were independent contributors to FVC decline. Conclusion In patients with SSc-ILD, FVC decline is attributable not only to the progression of ILD but also to the atrophy of accessory respiratory muscles. Our findings call attention to the interpretation of FVC changes in patients with SSc-ILD.

Deep breaths, methacholine, and airway narrowing in healthy and mild asthmatic subjects

2002 ◽  
Vol 93 (4) ◽  
pp. 1384-1390 ◽  
Author(s):  
Emanuele Crimi ◽  
Riccardo Pellegrino ◽  
Manlio Milanese ◽  
Vito Brusasco
Keyword(s):  
Forced Vital Capacity ◽  
Healthy Subjects ◽  
Vital Capacity ◽  
Forced Expiratory Volume ◽  
Forced Expiration ◽  
Airway Narrowing ◽  
Significant Difference ◽  
Mild Asthmatic ◽  
Residual Capacity ◽  
Airway Conductance

Deep breaths taken before inhalation of methacholine attenuate the decrease in forced expiratory volume in 1 s and forced vital capacity in healthy but not in asthmatic subjects. We investigated whether this difference also exists by using measurements not preceded by full inflation, i.e., airway conductance, functional residual capacity, as well as flow and residual volume from partial forced expiration. We found that five deep breaths preceding a single dose of methacholine 1) transiently attenuated the decrements in forced expiratory volume in 1 s and forced vital capacity in healthy ( n = 8) but not in mild asthmatic ( n = 10) subjects and 2) increased the areas under the curve of changes in parameters not preceded by a full inflation over 40 min, during which further deep breaths were prohibited, without significant difference between healthy ( n = 6) and mild asthmatic ( n = 16) subjects. In conclusion, a series of deep breaths preceding methacholine inhalation significantly enhances bronchoconstrictor response similarly in mild asthmatic and healthy subjects but facilitates bronchodilatation on further full inflation in the latter.

Chest wall impedance partitioned into rib cage and diaphragm-abdominal pathways

1989 ◽  
Vol 66 (1) ◽  
pp. 350-359 ◽  
Author(s):  
G. M. Barnas ◽  
K. Yoshino ◽  
D. Stamenovic ◽  
Y. Kikuchi ◽  
S. H. Loring ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Chest Wall ◽  
Viscoelastic Properties ◽  
Vital Capacity ◽  
Wall Surface ◽  
Body Plethysmography ◽  
Frequency Range ◽  
Entire Frequency Range ◽  
Rib Cage ◽  
Pressure Changes

We measured chest wall "pathway impedances" (ratios of pressure changes to rates of volume displacement at the surface) with esophageal and gastric balloons and inductance plethysmographic belts around the rib cage and abdomen during forced volume oscillations (5% vital capacity, 0.5–4 Hz) at the mouth of five relaxed, seated subjects. Volume displacements of the total chest wall surface, measured by summing the rib cage and abdominal signals, approximated measurements using volume-displacement, body plethysmography over the entire frequency range. Resistance (R) and elastance (E) of the diaphragm-abdomen pathway were several times greater than those of the rib cage pathway, except at the highest frequencies where diaphragm-abdominal E was small. R and E of the diaphragm-abdomen pathway and of the rib cage pathway showed the same frequency dependencies as that of the total chest wall: R decreased markedly as frequency increased, and E (especially in the diaphragm-abdomen) decreased at the highest frequencies. These results suggest that the chest wall can be reasonably modeled, over the frequency range studied, as a system with two major pathways for displacement. Each pathway seems to exhibit behavior that reflects nonlinear, rate-independent dissipation as well as viscoelastic properties. Impedances of these pathways are useful indexes of changes in chest wall mechanical behavior in different situations.

Ventilatory capacity during prolonged exposure to simulated altitude without hypoxia

1963 ◽  
Vol 18 (5) ◽  
pp. 904-908 ◽  
Author(s):  
F. Ulvedal ◽  
T. E. Morgan ◽  
R. G. Cutler ◽  
B. E. Welch
Keyword(s):  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Prolonged Exposure ◽  
Ground Level ◽  
Barometric Pressure ◽  
High Volume ◽  
Minute Volume ◽  
Respiratory Physiology ◽  
Physiological Processes ◽  
Reduced Density

Studies have been conducted in a sealed environment altitude chamber to study the chronic effect of reduced barometric pressure without reduced oxygen tension on human respiratory function and other physiological processes. Experiments were conducted at ground level, at 18,000 ft equivalent altitude (pO2 150 mm Hg), at 27,000 ft equivalent altitude (pO2 243 mm Hg), and at 33,500 ft equivalent altitude (pO2 174 mm Hg). Results were as follows: 1) Tests of pulmonary functions which are dependent on high volume flow rates are increased at altitude. These tests include maximum breathing capacity (increased 37% at 33,500 ft) and per cent of forced vital capacity during the first second of effort. 2) Expiratory minute volume was unchanged at altitude when oxygen partial pressure was maintained. 3) Forced vital capacity was reduced 3.1% at 18,000 ft, 2.9% at 27,000 ft, and 7.6% at 33,500 ft. This result was not due to hypoxia or abdominal distention and confirms the earlier findings of Rahn and Hammond. The cause of this change remains obscure but may be related to decreased lung volume. 4) The magnitude of changes observed appears to be somewhat proportional to altitude. Evidence is presented to relate increases in the flow-dependent tests to reduced density and reduced turbulent flow in the respiratory passages. respiratory physiology; sealed environment; spacecraft; atmosphere selection; space medicine Submitted on October 22, 1963

scholarly journals The Effect of Aerobic and Core Exercises on Forced Vital Capacity

2018 ◽  
Vol 77 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Güner Çiçek ◽  
Abdullah Güllü ◽  
Esin Güllü ◽  
Faruk Yamaner
Keyword(s):  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Maximal Oxygen Consumption ◽  
Exercise Program ◽  
Exercise Group ◽  
T Test ◽  
Forced Expiration ◽  
Core Strength ◽  
Strength Exercises ◽  
Sedentary Women

Abstract The aim of the study was to investigate the effect of aerobic and core strength exercises on forced vital capacity in sedentary women. A total of 40 healthy sedentary women (20 in an aerobic-step group and 20 in a core strength exercise group) with a mean age of 34.4±2.4 years participated voluntarily in this study. Two different exercises were applied to the women for 12 weeks, 4 days a week, at the intensity of 70% for 60 minutes. The women's resting heart rate (RHR), maximal oxygen consumption (VO2max), forced vital capacity (FVC), and forced air volume in the first second of forced expiration (FEV1) were measured before and after exercise. For statistical analysis, the Paired Samples-t test was used for intra-group evaluations, and the Independent Samples-t test was used for inter-group evaluations. After the exercise program, significant increases were found in the VO2max, FVC, and FEV1 values, while both groups experienced a decreased RHR (p<0.01). Since the aerobic and forced vital capacities of the sedentary women show a parallel increase as a result of the applied 12-week aerobic and core strength exercises, it can be said that the RHR, VO2maxmax, FEV, and FEV1 respiratory parameters also improved in a positive manner. For this reason, it may be advisable to apply both exercise types for the development of the aerobic and vital capacities of sedentary women.

Chest wall distortion during resistive inspiratory loading

1985 ◽  
Vol 58 (5) ◽  
pp. 1646-1653 ◽  
Author(s):  
E. R. Ringel ◽  
S. H. Loring ◽  
J. Mead ◽  
R. H. Ingram
Keyword(s):  
Chest Wall ◽  
Wall Motion ◽  
Respiratory Muscles ◽  
Underlying Mechanism ◽  
Abdominal Muscles ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Circular Configuration ◽  
Chest Wall Motion ◽  
Resistive Loads

We studied six (1 naive and 5 experienced) subjects breathing with added inspiratory resistive loads while we recorded chest wall motion (anteroposterior rib cage, anteroposterior abdomen, and lateral rib cage) and tidal volumes. In the five experienced subjects, transdiaphragmatic and pleural pressures, and electromyographs of the sternocleidomastoid and abdominal muscles were also measured. Subjects inspired against the resistor spontaneously and then with specific instructions to reach a target pleural or transdiaphragmatic pressure or to maximize selected electromyographic activities. Depending on the instructions, a wide variety of patterns of inspiratory motion resulted. Although the forces leading to a more elliptical or circular configuration of the chest wall can be identified, it is difficult to analyze or predict the configurational results based on insertional and pressure-related contributions of a few individual respiratory muscles. Although overall chest wall respiratory motion cannot be readily inferred from the electromyographic and pressure data we recorded, it is clear that responses to loading can vary substantially within and between individuals. Undoubtedly, the underlying mechanism for the distortional changes with loading are complex and perhaps many are behavioral rather than automatic and/or compensatory.

Positive effort dependence of maximal expiratory flow

1987 ◽  
Vol 62 (2) ◽  
pp. 718-724 ◽  
Author(s):  
J. L. Allen ◽  
R. G. Castile ◽  
J. Mead
Keyword(s):  
Chest Wall ◽  
Conformational Changes ◽  
Vital Capacity ◽  
Transpulmonary Pressure ◽  
Normal Subjects ◽  
Forced Expiration ◽  
Respiratory Inductive Plethysmography ◽  
Maximal Expiratory Flow ◽  
Expiratory Flow ◽  
Normal Males

The maximal expiratory-flow volume (MEFV) curve in normal subjects is thought to be relatively effort independent over most of the vital capacity (VC). We studied seven normal males and found positive effort dependence of maximal expiratory flow between 50 and 80% VC in five of them, as demonstrated by standard isovolume pressure-flow (IVPF) curves. We then attempted to distinguish the effects of chest wall conformational changes from possible mechanisms intrinsic to the lungs as an explanation for positive effort dependence. IVPF curves were repeated in four of the subjects who had demonstrated positive effort dependence. Transpulmonary pressure was varied by introducing varied resistances at the mouth but effort, as defined by pleural pressure, was maintained constant. By this method, chest wall conformation at a given volume would be expected to remain the same despite changing transpulmonary pressures. When these four subjects were retested in this way, no increases in flow with increasing transpulmonary pressure were found. In further studies, voluntarily altering the chest wall pattern of emptying (as defined by respiratory inductive plethysmography) did however alter maximal expiratory flows, with transpulmonary pressure maintained constant. We conclude that maximal expiratory flow can increase with effort over a larger portion of the vital capacity than is commonly recognized, and this effort dependence may be the result of changes in central airway mechanical properties that occur in relation to changes in chest wall shape during forced expiration.

Passive mechanics of upright human chest wall during immersion from hips to neck

1986 ◽  
Vol 60 (5) ◽  
pp. 1561-1570 ◽  
Author(s):  
M. B. Reid ◽  
S. H. Loring ◽  
R. B. Banzett ◽  
J. Mead
Keyword(s):  
Chest Wall ◽  
Esophageal Pressure ◽  
Vertical Surface ◽  
Repeated Measurements ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Gastric Pressure ◽  
Length Changes ◽  
Accessory Muscles

We have determined the mechanical effects of immersion to the neck on the passive chest wall of seated upright humans. Repeated measurements were made at relaxed end expiration on four subjects. Changes in relaxed chest wall configuration were measured using magnetometers. Gastric and esophageal pressures were measured with balloon-tipped catheters in three subjects; from these, transdiaphragmatic pressure was calculated. Transabdominal pressure was estimated using a fluid-filled, open-tipped catheter referenced to the abdomen's exterior vertical surface. We found that immersion progressively reduced mean transabdominal pressure to near zero and that the relaxed abdominal wall was moved inward 3–4 cm. The viscera were displaced upward into the thorax, gastric pressure increased by 20 cmH2O, and transdiaphragmatic pressure decreased by 10–15 cmH2O. This lengthened the diaphragm, elevating the diaphragmatic dome 3–4 cm. Esophageal pressure became progressively more positive throughout immersion, increasing by 8 cmH2O. The relaxed rib cage was elevated and expanded by raising water from hips to lower sternum; this passively shortened the inspiratory intercostals and the accessory muscles of inspiration. Deeper immersion distorted the thorax markedly: the upper rib cage was forced inward while lower rib cage shape was not systematically altered and the rib cage remained elevated. Such distortion may have passively lengthened or shortened the inspiratory muscles of the rib cage, depending on their location. We conclude that the nonuniform forcing produced by immersion provides unique insights into the mechanical characteristics of the abdomen and rib cage, that immersion-induced length changes differ among the inspiratory muscles according to their locations and the depth of immersion, and that such length changes may have implications for patients with inspiratory muscle deficits.

Chest wall motion during tidal breathing

1997 ◽  
Vol 83 (5) ◽  
pp. 1531-1537 ◽  
Author(s):  
A. De Groote ◽  
M. Wantier ◽  
G. Cheron ◽  
M. Estenne ◽  
M. Paiva
Keyword(s):  
Chest Wall ◽  
Wall Motion ◽  
Costal Cartilage ◽  
Three Dimensional ◽  
Normal Subjects ◽  
Costal Margin ◽  
Tidal Breathing ◽  
Lateral Direction ◽  
Rib Cage ◽  
Chest Wall Motion

De Groote, A., M. Wantier, G. Cheron, M. Estenne, and M. Paiva. Chest wall motion during tidal breathing. J. Appl. Physiol. 83(5): 1531–1537, 1997.—We have used an automatic motion analyzer, the ELITE system, to study changes in chest wall configuration during resting breathing in five normal, seated subjects. Two television cameras were used to record the x-y-z displacements of 36 markers positioned circumferentially at the level of the third (S1) and fifth (S2) costal cartilage, corresponding to the lung-apposed rib cage; midway between the xyphoid process and the costal margin (S3), corresponding to the abdomen-apposed rib cage; and at the level of the umbilicus (S4). Recordings of different subsets of markers were made by submitting the subject to five successive rotations of 45–90°. Each recording lasted 30 s, and three-dimensional displacements of markers were analyzed with the Matlab software. At spontaneous end expiration, sections S1–3 were elliptical but S4 was more circular. Tidal changes in chest wall dimensions were consistent among subjects. For S1–2, changes during inspiration occurred primarily in the cranial and ventral directions and averaged 3–5 mm; displacements in the lateral direction were smaller (1–2 mm). On the other hand, changes at the level of S4 occurred almost exclusively in the ventral direction. In addition, both compartments showed a ventral displacement of their dorsal aspect that was not accounted for by flexion of the spine. We conclude that, in normal subjects breathing at rest in the seated posture, displacements of the rib cage during inspiration are in the cranial, lateral outward, and ventral directions but that expansion of the abdomen is confined to the ventral direction.

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