Relationship of central and peripheral airway resistance to lung volume in dogs

1978 ◽  
Vol 44 (5) ◽  
pp. 728-737 ◽  
Author(s):  
F. G. Hoppin ◽  
M. Green ◽  
M. S. Morgan
Keyword(s):  
Lung Volume ◽  
Peripheral Resistance ◽  
Small Airways ◽  
Peripheral Airways ◽  
Tissue Resistance ◽  
Peripheral Airway ◽  
Phase Lags ◽  
A New Technique ◽  
Isotropic Expansion ◽  
Relationship Of

We could not reconcile reported relationships between lung resistance measurements and lung volume with bronchographic and anatomic studies showing that airway diameters change monotonically with lung volume and that small airways change diameter proportionately at least as much as large ones. Accordingly we measured central and peripheral airways resistances with a new technique. The relevant pressures were measured with a tracheal cannula, a wedged retrograde catheter, and two parenchymal needles in seven open-chested dogs while pleural pressure was oscillated at 1 Hz. In contrast to previous studies, the volume dependency of peripheral resistance was at least as great as that of central resistance with vagi intact, the volume dependencies of central and peripheral resistances were not abolished by vagotomy, and neither resistance increased systematically at high volumes. Volume dependency of central resistance resembled predictions for isotropic expansion of airways with vagi cut but increased with bronchomotor tone. These results fit generally with bronchographic data. Previous studies may have been affected by volume dependency due to “tissue resistance” and catheter phase lags.

The vulnerable small airway

PEDIATRICS ◽  
1977 ◽  
Vol 59 (5) ◽  
pp. 783-785
Author(s):  
V. Chernick
Keyword(s):  
Flow Resistance ◽  
Gas Flow ◽  
Airway Resistance ◽  
Clear Understanding ◽  
Small Airways ◽  
Peripheral Airways ◽  
Pulmonary Flow ◽  
Peripheral Airway ◽  
First Time

Fundamental physiological work in the late 1960s provided for the first time a clear understanding of (1) the role of the small airways (< 2 mm in diameter) in determining overall airway resistance to gas flow and (2) the relationship between central and peripheral airway resistance and lung growth.1,2 Involvement of the small airways early in the course of cystic fibrosis has been previously commented upon and documented in Pediatrics.3-5 After the age of about 5 years, the flow resistance of peripheral airways constitutes only about 10% to 20% of total pulmonary flow resistance,2 a fraction so small that conventional measurement of total resistance cannot detect small changes in the peripheral component.

Control of bronchomotor tone during perinatal development in sheep

1993 ◽  
Vol 75 (4) ◽  
pp. 1486-1496 ◽  
Author(s):  
J. J. Perez Fontan ◽  
L. P. Kinloch
Keyword(s):  
Airway Resistance ◽  
Vagal Stimulation ◽  
Peripheral Resistance ◽  
Term Newborn ◽  
Peripheral Airways ◽  
Pleural Surface ◽  
Peripheral Airway ◽  
Cervical Vagotomy ◽  
Central Airway ◽  
Bronchomotor Tone

To characterize the perinatal maturation of the cholinergic control of the airways, we compared the effects of bilateral cervical vagotomy and supramaximal vagal stimulation on the airway resistances of 7 premature (130–133 days of gestation), 11 term newborn, and 9 9-wk-old lambs anesthetized with pentobarbital. Resistances were partitioned between central and peripheral airways with catheters placed retrogradely into peripheral bronchi and capsules attached to the pleural surface in communication with subpleural air spaces. The central and peripheral airway resistances of premature and term newborn lambs and the peripheral resistance of 9-wk-old lambs decreased after vagotomy but only when the lungs were ventilated with small tidal volumes at mean transpulmonary pressures < or = 7.5 cmH2O. Vagotomy caused smaller absolute changes in central airway resistance than vagal stimulation. In contrast, both vagotomy and vagal stimulation produced similar absolute changes in peripheral airway resistance, indicating that resting cholinergic outflow is preferentially distributed to the peripheral airways even at the earlier ages. The effects of vagal stimulation on airway resistance were prevented by atropine. Our results prove that a resting bronchomotor tone can be present in both central and peripheral airways before the term of gestation in sheep. This tone depends on the activity of cholinergic fibers in the vagus and can be regionally controlled.

scholarly journals Small airways dysfunction: the link between allergic rhinitis and allergic asthma

2018 ◽  
Vol 51 (2) ◽  
pp. 1701749 ◽  
Author(s):  
Amaryllis Haccuria ◽  
Alain Van Muylem ◽  
Andrei Malinovschi ◽  
Vi Doan ◽  
Alain Michils
Keyword(s):  
Allergic Rhinitis ◽  
Allergic Asthma ◽  
Sulfur Hexafluoride ◽  
Phase Iii ◽  
No Production ◽  
Small Airways ◽  
Sputum Induction ◽  
Airway Reactivity ◽  
Peripheral Airways ◽  
Peripheral Airway

Abnormal airway reactivity and overproduction of nitric oxide (NO) occurring in small airways have been found in asthma. If the “one airway, one disease” concept is consistent, such dysfunctions should also be detected in the peripheral airways of patients suffering from allergic rhinitis.We investigated whether peripheral airway reactivity and NO overproduction could be documented in distal airways in patients with allergic rhinitis. Exhaled NO fraction (FeNO) and the slope (S) of phase III of the single-breath washout test (SBWT) of helium (He) and sulfur hexafluoride (SF6) were measured in 31 patients with allergic asthma, 23 allergic rhinitis patients and 24 controls, before and after sputum induction. SBWT is sensitive to airway calibre change occurring in the lung periphery.The FeNO decrease was more significant in asthma and rhinitis than in controls (−55.1% and −50.0%, respectively, versus −40.8%) (p=0.007 and p=0.029, respectively). SSF6 and SHe increased in all groups. Change in SHe (ΔSHe) > ΔSSF6 was observed in rhinitis (p=0.004) and asthma (p<0.001), whereas ΔSSF6 = ΔSHe in controls (p=0.431).This study provides evidence of peripheral airway dysfunction in patients with allergic rhinitis quite similar to that described in asthma. Furthermore, a large proportion of the increased NO production reported in allergic rhinitis appears to originate in the peripheral airways.

Ventilation Heterogeneity Of Peripheral Airways (Sacin*VT) Assessed By Nitrogen Multiple Breath Washout (N2-MBW) Is An Accurate and Sensitive Marker Of Bronchiolitis Obliterans Following Haematopoietic Stem Cell Transplantation Recipients

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4599-4599
Author(s):  
Federica De Giacomi ◽  
Maria Teresa Lupo-Stanghellini ◽  
Alessia Orsini ◽  
Elena Guggiari ◽  
Consuelo Corti ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Bronchiolitis Obliterans ◽  
Haematopoietic Stem Cell Transplantation ◽  
Haematopoietic Stem Cell ◽  
Small Airways ◽  
Peripheral Airways ◽  
Peripheral Airway ◽  
Multiple Breath Washout

Bronchiolitis Obliterans (BO) initially affects terminal and respiratory bronchioles, a region of the lung largely unexplored by spirometry, which is only altered in advanced disease. In contrast, the Impulse Oscillation System (IOS) and the nitrogen multiple breath washout (N2-MBW) are techniques characterized by a high sensitivity to peripheral airway changes and potentially more suited to early detection of small airways disease. In a cross sectional study, a total of 161 patients, divided into 4 groups: healthy controls (n=41), bone marrow transplant candidates (n=47), haematopoietic stem cell transplantation (HSCT) recipients (n=65) and patients with chronic obstructive pulmonary disease (COPD; n=8), were assessed by IOS, N2-MBW, spirometry, body plethysmography and diffusing capacity for carbon monoxide (DLCO) in order to describe respiratory function changes in post-transplant patients without pulmonary graft versus host disease (GVHD) and in order to characterize the pattern of peripheral airway changes in BO. All subjects were able to perform IOS and N2-MBW without difficulty. Significant variables are illustrated in the table.ControlNo BOSpBOSpMSDMSDMSDRV/TLC %9714109240.04414422<0.001DLCO %96880160.0024911<0.001Scond* VT [l]0.020.010.030.02<0.0010.020.01<0.001Sacin* VT [l]0.050.020.130.09<0.0010.370.20<0.001Z5Hz [cmH2O/(l/s)]3.070.673.491.29NS4.932.460.017DR5-20Hz [cmH2O/(l/s)]0.300.230.560.68NS1.250.960.016X5Hz [cmH2O/(l/s)]-0.950.21-1.130.77NS-2.271.980.002fR [1/s)]10.632.5413.194.86NS20.346.39<0.001Rperipheral [cmH2O/(l/s)]1.770.802.091.46NS3.703.060.026 Stem cell transplantation, even without respiratory complications, does not affect spirometry but appears to cause an increase in air trapping, a reduction in DLCO and enhanced ventilation inhomogeneity both in conductive (Scond*VT) and acinar (Sacin*VT) airways. Patients with BO (n=8) were characterized by further DLCO reduction, increase in oscillometric indices sensible to peripheral airways involvement (Z5Hz, DR5-20Hz, X5Hz, Resonant frequency and Rperipheral) and a further three-fold increase in Sacin* VT. Compared to patients with BO, COPD patients with the same degree of spirometric obstruction (FEV1/FVC< 0.7, FEV1 50% predicted) showed only half the increase in predicted Sacin*VT (p= 0.03). At a cut off of 321% of predicted value, Sacin* VT could distinguish the subjects with BO from recipients, with good accuracy (87%), sensibility (87.5%) and specificity (89.5%). We conclude that IOS and N2-MBW are simple tests able to detect changes following HSCT as well as those specific to Bronchiolitis Obliterans. Disclosures: No relevant conflicts of interest to declare.

Relationship of end-expiratory pressure, lung volume, and 99mTc-DTPA clearance

1987 ◽  
Vol 63 (4) ◽  
pp. 1586-1590 ◽  
Author(s):  
J. A. Cooper ◽  
H. van der Zee ◽  
B. R. Line ◽  
A. B. Malik
Keyword(s):  
Lung Volume ◽  
Clearance Rate ◽  
Base Line ◽  
Lung Inflation ◽  
Alveolar Epithelial ◽  
Pulmonary Clearance ◽  
Residual Capacity ◽  
Dose Response Effect ◽  
Relationship Of ◽  
Line P

We investigated the dose-response effect of positive end-expiratory pressure (PEEP) and increased lung volume on the pulmonary clearance rate of aerosolized technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA). Clearance of lung radioactivity was expressed as percent decrease per minute. Base-line clearance was measured while anesthetized sheep (n = 20) were ventilated with 0 cmH2O end-expiratory pressure. Clearance was remeasured during ventilation at 2.5, 5, 10, 15, or 20 cmH2O PEEP. Further studies showed stepwise increases in functional residual capacity (FRC) (P less than 0.05) measured at 0, 2.5, 5, 10, 15, and 20 cmH2O PEEP. At 2.5 cmH2O PEEP, the clearance rate was not different from that at base line (P less than 0.05), although FRC was increased from base line. Clearance rate increased progressively with increasing PEEP at 5, 10, and 15 cmH2O (P less than 0.05). Between 15 and 20 cmH2O PEEP, clearance rate was again unchanged, despite an increase in FRC. The pulmonary clearance of aerosolized 99mTc-DTPA shows a sigmoidal response to increasing FRC and PEEP, having both threshold and maximal effects. This relationship is most consistent with the hypothesis that alveolar epithelial permeability is increased by lung inflation.

Airway closure and reopening assessed by the alveolar capsule oscillation technique

1996 ◽  
Vol 80 (6) ◽  
pp. 2077-2084 ◽  
Author(s):  
D. R. Otis ◽  
F. Petak ◽  
Z. Hantos ◽  
J. J. Fredberg ◽  
R. D. Kamm
Keyword(s):  
Lung Volume ◽  
Input Impedance ◽  
Transpulmonary Pressure ◽  
Closing Volume ◽  
Airway Closure ◽  
Breathing Cycle ◽  
Abrupt Increase ◽  
Consistent Effect ◽  
Peripheral Airways

An alveolar capsule oscillation technique was used to determine 1) the lobe pressure and volume at which airways close and reopen, 2) the effect of expiration rate on closing volume and pressure, 3) the phase in the breathing cycle at which airway closure occurs, and 4) the site of airway closure. Experiments were conducted in excised dog lobes; closure was detected by an abrupt increase in the input impedance of surfacemounted alveolar capsules. Mean transpulmonary pressure (Ptp) at closure was slightly less than zero (Ptp = -2.3 cmH2O); the corresponding mean reopening pressure was Ptp = 14 cmH2O. The expiration rate varied between 1 and 20% of total lobe capacity per second and had no consistent effect on the closing volume and pressure. When lung volume was cycled up to frequencies of 0.2 Hz, closure generally occurred on expiration rather than inspiration. These observations support the conclusion that mechanical collapse, rather than meniscus formation, is the most likely mechanism producing airway closure in normal excised dog lungs. Analysis of measured acoustic impedances and reopening pressures suggests that closure occurs in the most peripheral airways. Reopening during inspiration was often observed to consist of a series of stepwise decreases in capsule impedance, indicating a sequence of opening events.

Flow-Volume Curves in Infants with Lung Disease

PEDIATRICS ◽  
1983 ◽  
Vol 72 (4) ◽  
pp. 517-522
Author(s):  
S. Godfrey ◽  
E. Bar-Yishay ◽  
I. Arad ◽  
L. I. Landau ◽  
L. M. Taussig
Keyword(s):  
Lung Disease ◽  
Airway Obstruction ◽  
Lung Volume ◽  
Airway Resistance ◽  
Whole Body ◽  
Small Airways ◽  
Forced Expiration ◽  
Flow Volume ◽  
Complete Evaluation ◽  
Expiratory Flow

Partial expiratory flow-volume maneuvers have been performed on nine occasions on six infants with a variety of pulmonary problems using a new tech nique for thoracic compression. The infants were placed within an inflatable bag that was, itself, within a canvas bag. By sudden controlled inflation of the inner bag at end inspiration, partial expiratory flow-volume curves were generated and recorded by means of a face mask and pneumotachograph. By comparing these flow results with those airway resistance and lung volume measurements obtained from the infants in whole body plethysmography and by noting the effect of inhaling a helium/oxygen gas mixture, it was possible to partition the airway obstruction between large and small airways. The presence of small airway obstruction was noted in the absence of changes in airway resistance or lung volume in several instances. A complete evaluation of airway function should include this test of forced expiration for greater understanding and treatment of lung disease in infancy.

Airway surface liquid thickness as a function of lung volume in small airways of the guinea pig

1994 ◽  
Vol 77 (5) ◽  
pp. 2333-2340 ◽  
Author(s):  
D. Yager ◽  
T. Cloutier ◽  
H. Feldman ◽  
J. Bastacky ◽  
J. M. Drazen ◽  
...  
Keyword(s):  
Surface Tension ◽  
Epithelial Cells ◽  
Guinea Pig ◽  
Cross Sections ◽  
Lung Volume ◽  
Longitudinal Direction ◽  
Small Airways ◽  
Airway Surface Liquid ◽  
Residual Capacity ◽  
Surface Liquid

The average thickness and distribution of airway surface liquid (ASL) on the luminal surface of peripheral airways were measured in normal guinea pig lungs frozen at functional residual capacity (FRC) and total lung capacity (TLC). Tissue blocks containing cross sections of airways of internal perimeter 0.188–3.342 mm were cut from frozen lungs and imaged by low-temperature scanning electron microscopy (LTSEM). Measurements made from LTSEM images were found to be independent of freezing rate by comparison of measurements at rapid and slow freezing rates. At both lung volumes, the ASL was not uniformly distributed in either the circumferential or longitudinal direction; there were regions of ASL where its thickness was < 0.1 micron, whereas in other regions ASL collected in pools. Discernible liquid on the surfaces of airways frozen at FRC followed the contours of epithelial cells and collected in pockets formed by neighboring cells, a geometry consistent with a low value of surface tension at the air-liquid interface. At TLC airway liquid collected to cover epithelial cells and to form a liquid meniscus, a geometry consistent with a higher value of surface tension. The average ASL thickness (h) was approximately proportional to the square root of airway internal perimeter, regardless of lung volume. For airways of internal perimeter 250 and 1,800 microns, h was 0.9 and 1.8 microns at FRC and 1.7 and 3.7 microns at TLC, respectively. For a given airway internal perimeter, h was 1.99 times thicker at TLC than at FRC; the difference was statistically significant (P < 0.01; 95% confidence interval 1.29–3.08).(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid increase in mast cell numbers in canine central and peripheral airways

1988 ◽  
Vol 65 (1) ◽  
pp. 445-451 ◽  
Author(s):  
C. R. Turner ◽  
J. Kolbe ◽  
E. W. Spannhake
Keyword(s):  
Mast Cell ◽  
Airway Epithelium ◽  
Time Course ◽  
Isotonic Saline ◽  
Cell Movement ◽  
Cell Number ◽  
Small Airways ◽  
Cell Numbers ◽  
Peripheral Airways ◽  
Cell Counts

In preliminary studies of antigen-induced airway inflammation, we noted an apparent increase in peribronchiolar mast cell number. Experiments were thus undertaken to investigate the nature of this migration of mast cells into the central and peripheral airway epithelium and to determine its time course. The tracheae and small airways of 10 anesthetized mongrel dogs were exposed via a bronchoscope to Ascaris suum antigen (Ag), fMet-Leu-Phe (fMLP), ovalbumin (OVA), and isotonic saline (SAL). In the central airways, all stimuli provoked a significant increase (P less than 0.05) in mast cell numbers at the base of the airway epithelium within 3 h. In the peripheral airways, only Ag aerosol stimulated a significant mast cell increase compared with unexposed tissue. In a second series of experiments, the trachea of seven dogs were exposed to 0.026, 0.26, and 2.6 micrograms of Ag. The tissue was collected at 1, 3, 6, and 10 h after exposure. In these experiments, there was a significant mast cell increase seen within 1 h but it was not dose dependent. By 6-10 h after exposure, mast cell counts were not significantly different from the unexposed condition, which is consistent with the idea that some of the cells either degranulated or migrated into the airway lumen. We conclude that mast cell migration is an acute response that can be demonstrated within 1 h of stimulation with Ag. The observation that nonimmunological stimuli may, in some cases, also stimulate mast cell movement affords the possibility that this process represents a generalized response to airway irritation.

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