Hysteresis in the relation between diffusing capacity of the lung and lung volume

1980 ◽  
Vol 49 (4) ◽  
pp. 566-570 ◽  
Author(s):  
S. S. Cassidy ◽  
M. Ramanathan ◽  
G. L. Rose ◽  
R. L. Johnson
Keyword(s):  
Carbon Monoxide ◽  
Functional Residual Capacity ◽  
Lung Volume ◽  
Total Lung Capacity ◽  
Breath Holding ◽  
Residual Volume ◽  
Diffusing Capacity ◽  
Lung Volumes ◽  
Lung Capacity ◽  
Residual Capacity

The diffusing capacity of the lung for carbon monoxide (DLCO) varies directly with lung volume (VA) when measured during a breath-holding interval. DLCO measured during a slow exhalation from total lung capacity (TLC) to functional residual capacity (FRC) does not vary as VA changes. Since VA is reached by inhaling during breath holding and by exhaling during the slow exhalation maneuver, we hypothesized that the variability in the relation between DLCO and VA was due to hysteresis. To test this hypothesis, breath-holding measurements of DLCO were made at three lung volumes, both when VA was reached by inhaling from residual volume (RV) and when Va was reached by exhaling from TLC. At 72% TLC, DLCO was 22% higher when VA was reached by exhalation compared to inhalation (P < 0.02). At 52% TLC, DLCO was 19% higher when VA was reached by exhalation compared to exhalation (P < 0.005). DCLO measured during a slow exhalation fell on the exhalation limb of the CLCO/VA curve. these data indicate that there is hysteresis in DLCO with respect to lung volume.

Lung volumes of singers

1960 ◽  
Vol 15 (1) ◽  
pp. 40-42 ◽  
Author(s):  
Stanley S. Heller ◽  
William R. Hicks ◽  
Walter S. Root
Keyword(s):  
Lung Volume ◽  
Vital Capacity ◽  
Total Lung Capacity ◽  
Residual Volume ◽  
Inspiratory Capacity ◽  
Lung Volumes ◽  
Lung Capacity ◽  
Vocal Training ◽  
Professional Singers ◽  
Residual Capacity

Lung volume determinations (tidal volume, inspiratory capacity, inspiratory reserve volume, expiratory reserve volume, vital capacity, maximum breathing capacity, functional residual capacity, residual volume, and total lung capacity) were carried out on 16 professional singers and 21 subjects who had had no professional vocal training. No differences were found between the two groups of subjects, whether recumbent or standing, which could not be explained upon the basis of age, size, or errors involved in making the measurements. Submitted on March 24, 1959

Lung volume effects on pharyngeal swallowing physiology

2003 ◽  
Vol 95 (6) ◽  
pp. 2211-2217 ◽  
Author(s):  
Roxann Diez Gross ◽  
Charles W. Atwood ◽  
Judith P. Grayhack ◽  
Susan Shaiman
Keyword(s):  
Functional Residual Capacity ◽  
Lung Volume ◽  
Total Lung Capacity ◽  
Regulatory Function ◽  
Residual Volume ◽  
Bolus Transit ◽  
Repeated Measures Design ◽  
Lung Capacity ◽  
Residual Capacity ◽  
Intramuscular Electromyography

The experiment was a prospective, repeated-measures design intended to determine how the variation of lung volume affects specific measures of swallowing physiology. Swallows were recorded in 28 healthy subjects, who ranged in age from 21 to 40 yr (mean age of 29 yr), by using simultaneous videofluoroscopy, bipolar intramuscular electromyography, and respiratory inductance plethysmography. Each subject swallowed three standardized pudding-like consistency boluses at three randomized lung volumes: total lung capacity, functional residual capacity, and residual volume. The results showed that pharyngeal activity duration of deglutition for swallows produced at residual volume was significantly longer than those occurring at total lung capacity or at functional residual capacity. No significant differences were found for bolus transit time or intramuscular electromyography of the superior constrictor. The results of this experiment lend support to the hypothesis that the respiratory system may have a regulatory function related to swallowing and that positive subglottic air pressure may be important for swallowing integrity. Eventually, new treatment paradigms for oropharyngeal dysphagia that are based on respiratory physiology may be developed.

STUDIES OF RESPIRATORY PHYSIOLOGY IN CHILDREN

PEDIATRICS ◽  
1959 ◽  
Vol 24 (2) ◽  
pp. 181-193
Author(s):  
C. D. Cook ◽  
P. J. Helliesen ◽  
L. Kulczycki ◽  
H. Barrie ◽  
L. Friedlander ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Respiratory Rate ◽  
Vital Capacity ◽  
Total Lung Capacity ◽  
Lung Compliance ◽  
Respiratory Physiology ◽  
Residual Volume ◽  
Lung Volumes ◽  
Lung Capacity ◽  
Residual Capacity

Tidal volume, respiratory rate and lung volumes have been measured in 64 patients with cystic fibrosis of the pancreas while lung compliance and resistance were measured in 42 of these. Serial studies of lung volumes were done in 43. Tidal volume was reduced and the respiratory rate increased only in the most severely ill patients. Excluding the three patients with lobectomies, residual volume and functional residual capacity were found to be significantly increased in 46 and 21%, respectively. These changes correlated well with the roentgenographic evaluation of emphysema. Vital capacity was significantly reduced in 34% while total lung capacity was, on the average, relatively unchanged. Seventy per cent of the 61 patients had a signficantly elevated RV/TLC ratio. Lung compliance was significantly reduced in only the most severely ill patients but resistance was significantly increased in 35% of the patients studied. The serial studies of lung volumes showed no consistent trends among the groups of patients in the period between studies. However, 10% of the surviving patients showed evidence of significant improvement while 15% deteriorated. [See Fig. 8. in Source Pdf.] Although there were individual discrepancies, there was a definite correlation between the clinical evaluation and tests of respiratory function, especially the changes in residual volume, the vital capacity, RV/ TLC ratio and the lung compliance and resistance.

Effect of Lung Volume on Voice Onset Time (VOT)

1993 ◽  
Vol 36 (3) ◽  
pp. 516-520 ◽  
Author(s):  
Jeannette D. Hoit ◽  
Nancy Pearl Solomon ◽  
Thomas J. Hixon
Keyword(s):  
Lung Volume ◽  
Total Lung Capacity ◽  
Voice Onset Time ◽  
Onset Time ◽  
Speech Disorders ◽  
Residual Volume ◽  
Healthy Individuals ◽  
Lung Volumes ◽  
Lung Capacity

This investigation was designed to test the hypothesis that voice onset time (VOT) varies as a function of lung volume. Recordings were made of five men as they repeated a phrase containing stressed /pi/ syllables, beginning at total lung capacity and ending at residual volume. VOT was found to be longer at high lung volumes and shorter at low lung volumes in most cases. This finding points out the need to take lung volume into account when using VOT as an index of laryngeal behavior in both healthy individuals and those with speech disorders.

Effects of lung volume on collateral and airways resistance in man

1979 ◽  
Vol 46 (1) ◽  
pp. 67-73 ◽  
Author(s):  
C. R. Inners ◽  
P. B. Terry ◽  
R. J. Traystman ◽  
H. A. Menkes
Keyword(s):  
Functional Residual Capacity ◽  
Lung Volume ◽  
Total Lung Capacity ◽  
Lung Capacity ◽  
Residual Capacity ◽  
Collateral Pathways ◽  
Flow Through ◽  
Airways Resistance ◽  
Young Subjects ◽  
The Relationship

The effects of changing lung volume (VL) on collateral resistance (Rcoll) and total airways resistance (Raw) were compared in six young volunteers. At functional residual capacity (FRC) = 55% total lung capacity (TLC), mean Rcoll was 4,664 +/- 1,518 (SE) cmH2O/(l/s) and mean Raw was 1.57 +/- 0.11 (SE) cmH2O/l/s). When VL increased to 80% TLC, Rcoll decreased by 63.3 +/- 7.8%, and Raw decreased by 50.3 +/- 4.2 (SE) %. The decrease in Rcoll with increasing lung volume was not statistically different from that of Raw (P less than 0.05). If the airways obstructed for measurements of Rcoll served between 2 and 5% of the lungs, then Rcoll was approximately 50 times as great as the resistance to flow through airways serving the same volume of lung at FRC. The relationship did not change significantly when VL increased by 25% TLC. If changes in Raw reflect changes in airways supplying sublobar portions of lung, these results indicate that there is no tendency for the redistribution of ventilation through airways and collateral pathways with changes in VL in young subjects.

Respiratory changes in diaphragmatic intramuscular pressure

1990 ◽  
Vol 68 (1) ◽  
pp. 35-43 ◽  
Author(s):  
M. Decramer ◽  
T. X. Jiang ◽  
M. B. Reid
Keyword(s):  
Functional Residual Capacity ◽  
Total Lung Capacity ◽  
Residual Volume ◽  
Intramuscular Pressure ◽  
Phrenic Nerve Stimulation ◽  
Direct Stimulation ◽  
Lung Capacity ◽  
Residual Capacity ◽  
Anesthetized Dogs ◽  
Stimulation Of

We attempted to measure diaphragmatic tension by measuring changes in diaphragmatic intramuscular pressure (Pim) in the costal and crural parts of the diaphragm in 10 supine anesthetized dogs with Gaeltec 12 CT minitransducers. During phrenic nerve stimulation or direct stimulation of the costal and crural parts of the diaphragm in an animal with the chest and abdomen open, Pim invariably increased and a linear relationship between Pim and the force exerted on the central tendon was found (r greater than or equal to 0.93). During quiet inspiration Pim in general decreased in the costal part (-3.9 +/- 3.3 cmH2O), whereas it either increased or slightly decreased in the crural part (+3.3 +/- 9.4 cmH2O, P less than 0.05). Similar differences were obtained during loaded and occluded inspiration. After bilateral phrenicotomy Pim invariably decreased during inspiration in both parts (costal -4.3 +/- 6.4 cmH2O, crural -3.1 +/- 0.6 cmH2O). Contrary to the expected changes in tension in the muscle, but in conformity with the pressure applied to the muscle, Pim invariably increased during passive inflation from functional residual capacity to total lung capacity (costal +30 +/- 23 cmH2O, crural +18 +/- 18 cmH2O). Similarly, during passive deflation from functional residual capacity to residual volume, Pim invariably decreased (costal -12 +/- 19 cmH2O, crural -12 +/- 14 cmH2O). In two experiments similar observations were made with saline-filled catheters. We conclude that although Pim increases during contraction as in other muscles, Pim during respiratory maneuvers is primarily determined by the pleural and abdominal pressures applied to the muscle rather than by the tension developed by it.

scholarly journals Comparison of inspiratory and expiratory lung and lobe volumes among supine, standing, and sitting positions using conventional and upright CT

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yoshitake Yamada ◽  
Minoru Yamada ◽  
Shotaro Chubachi ◽  
Yoichi Yokoyama ◽  
Shiho Matsuoka ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Functional Residual Capacity ◽  
Supine Position ◽  
Total Lung Capacity ◽  
Middle Lobe ◽  
Inspiratory Capacity ◽  
Lung Volumes ◽  
Lung Capacity ◽  
Residual Capacity ◽  
Right Middle Lobe

Abstract Currently, no clinical studies have compared the inspiratory and expiratory volumes of unilateral lung or of each lobe among supine, standing, and sitting positions. In this prospective study, 100 asymptomatic volunteers underwent both low-radiation-dose conventional (supine position, with arms raised) and upright computed tomography (CT) (standing and sitting positions, with arms down) during inspiration and expiration breath-holds and pulmonary function test (PFT) on the same day. We compared the inspiratory/expiratory lung/lobe volumes on CT in the three positions. The inspiratory and expiratory bilateral upper and lower lobe and lung volumes were significantly higher in the standing/sitting positions than in the supine position (5.3–14.7% increases, all P < 0.001). However, the inspiratory right middle lobe volume remained similar in the three positions (all P > 0.15); the expiratory right middle lobe volume was significantly lower in the standing/sitting positions (16.3/14.1% decrease) than in the supine position (both P < 0.0001). The Pearson’s correlation coefficients (r) used to compare the total lung volumes on inspiratory CT in the supine/standing/sitting positions and the total lung capacity on PFT were 0.83/0.93/0.95, respectively. The r values comparing the total lung volumes on expiratory CT in the supine/standing/sitting positions and the functional residual capacity on PFT were 0.83/0.85/0.82, respectively. The r values comparing the total lung volume changes from expiration to inspiration on CT in the supine/standing/sitting positions and the inspiratory capacity on PFT were 0.53/0.62/0.65, respectively. The study results could impact preoperative CT volumetry of the lung in lung cancer patients (before lobectomy) for the prediction of postoperative residual pulmonary function, and could be used as the basis for elucidating undetermined pathological mechanisms. Furthermore, in addition to morphological evaluation of the chest, inspiratory and expiratory upright CT may be used as an alternative tool to predict lung volumes such as total lung capacity, functional residual capacity, and inspiratory capacity in situation in which PFT cannot be performed such as during an infectious disease pandemic, with relatively more accurate predictability compared with conventional supine CT.

scholarly journals Influence of lung volume on pulmonary microvascular pressure-volume characteristics

2000 ◽  
Vol 89 (4) ◽  
pp. 1591-1600 ◽  
Author(s):  
George P. Topulos ◽  
Richard E. Brown ◽  
James P. Butler
Keyword(s):  
Lung Volume ◽  
Total Lung Capacity ◽  
Lung Volumes ◽  
Vascular Volume ◽  
Lung Capacity ◽  
Transit Times ◽  
Wide Range ◽  
Residual Capacity ◽  
Volume Characteristics ◽  
Lung Microcirculation

The pressure-volume (P-V) characteristics of the lung microcirculation are important determinants of the pattern of pulmonary perfusion and of red and white cell transit times. Using diffuse light scattering, we measured capillary P-V loops in seven excised perfused dog lobes at four lung volumes, from functional residual capacity (FRC) to total lung capacity (TLC), over a wide range of vascular transmural pressures (Ptm). At Ptm 5 cmH2O, specific compliance of the microvasculature was 8.6%/cmH2O near FRC, decreasing to 2.7%/cmH2O as lung volume increased to TLC. At low lung volumes, the vasculature showed signs of strain stiffening (specific compliance fell as Ptm rose), but stiffening decreased as lung volume increased and was essentially absent at TLC. The P-V loops were smooth without sharp transitions, consistent with vascular distension as the primary mode of changes in vascular volume with changes in Ptm. Hysteresis was small (0.013) at all lung volumes, suggesting that, although surface tension may set basal capillary shape, it does not strongly affect capillary compliance.

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