scholarly journals Exercise-induced bronchodilation in natural and induced asthma: effects on ventilatory response and performance

2002 ◽  
Vol 92 (6) ◽  
pp. 2353-2360 ◽  
Author(s):  
Emanuele Crimi ◽  
Riccardo Pellegrino ◽  
Attilio Smeraldi ◽  
Vito Brusasco
Keyword(s):  
Tidal Volume ◽  
Functional Residual Capacity ◽  
Lung Volume ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Breathing Frequency ◽  
Forced Expiratory Flow ◽  
Residual Capacity ◽  
Group 2 ◽  
Group 1

We studied whether bronchodilatation occurs with exercise during the late asthmatic reaction (LAR) to allergen ( group 1, n = 13) or natural asthma (NA; group 2, n = 8) and whether this is sufficient to preserve maximum ventilation (V˙e max), oxygen consumption (V˙o 2 max), and exercise performance (W˙max ). In group 1, partial forced expiratory flow at 30% of resting forced vital capacity increased during exercise, both at control and LAR. W˙max was slightly reduced at LAR, whereasV˙e max, tidal volume, breathing frequency, and V˙o 2 max were preserved. Functional residual capacity and end-inspiratory lung volume were significantly larger at LAR than at control. In group 2, partial forced expiratory flow at 30% of resting forced vital capacity increased greatly with exercise during NA but did not attain control values after appropriate therapy. Compared with control, W˙max was slightly less during NA, whereas V˙o 2 maxand V˙e max were similar. Functional residual capacity, but not end-inspiratory lung volume at maximum load, was significantly greater than at control, whereas tidal volume decreased and breathing frequency increased. In conclusion, remarkable exercise bronchodilation occurs during either LAR or NA and allowsV˙e max andV˙o 2 max to be preserved with small changes in breathing pattern and a slight reduction inW˙max.

Effect of lung volume on forced expiratory flows during rapid thoracoabdominal compression in infants

1995 ◽  
Vol 78 (5) ◽  
pp. 1993-1997 ◽  
Author(s):  
J. Hammer ◽  
C. J. Newth
Keyword(s):  
Lung Volume ◽  
Vital Capacity ◽  
Forced Expiration ◽  
Flow Volume ◽  
Older Children ◽  
Lung Volumes ◽  
Volume Segment ◽  
Forced Expiratory Flow ◽  
Residual Capacity ◽  
End Tidal

The rapid thoracoabdominal compression (RTC) technique is commonly used in pulmonary function laboratories to assess flow-volume relationships in infants unable to produce a voluntary forced expiration maneuver. This technique produces forced expiratory flows over only a small lung volume segment (i.e., tidal volume). It has been argued that the RTC technique should be modified to measure flow-volume relationships over a larger portion of the vital capacity range to imitate the voluntary maximal forced expiratory maneuver obtained in older children and adults. We examined the effect of volume history on forced expiratory flows by generating forced expiratory flow-volume curves by RTC from well-defined inspiratory volumes delineated by inspiratory pressures of 10, 20, 30, and 40 cmH2O down to residual volume (i.e., the reference volume) in seven intubated and anesthetized infants with normal lungs [age 8.0 +/- 2.0 (SE) mo, weight 6.7 +/- 0.6 kg]. We compared maximal expiratory flows at isovolume points (25 and 10% of forced vital capacity) and found no significant differences in maximal isovolume flow rates measured from the different lung volumes. We conclude that there is no obvious need to initiate RTC from higher lung volumes if the technique is used for flow comparisons. However, compared with measurements of maximal flows at functional residual capacity by RTC from end-tidal inspiration, the initiation of RTC from a defined and reproducible inspiratory level appears to decrease the intrasubject variability of the maximal expiratory flows at low lung volumes.

VA/Q distribution during heavy exercise and recovery in humans: implications for pulmonary edema

1992 ◽  
Vol 72 (5) ◽  
pp. 1657-1667 ◽  
Author(s):  
W. Schaffartzik ◽  
D. C. Poole ◽  
T. Derion ◽  
K. Tsukimoto ◽  
M. C. Hogan ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Pulmonary Edema ◽  
Vital Capacity ◽  
Heavy Exercise ◽  
Blood Flows ◽  
Arterial Ph ◽  
Interstitial Pulmonary Edema ◽  
Forced Expiratory Flow ◽  
Group 2 ◽  
Group 1

Ventilation-perfusion (VA/Q) inequality has been shown to increase with exercise. Potential mechanisms for this increase include nonuniform pulmonary vasoconstriction, ventilatory time constant inequality, reduced large airway gas mixing, and development of interstitial pulmonary edema. We hypothesized that persistence of VA/Q mismatch after ventilation and cardiac output subside during recovery would be consistent with edema; however, rapid resolution would suggest mechanisms related to changes in ventilation and blood flow per se. Thirteen healthy males performed near-maximal cycle ergometry at an inspiratory PO2 of 91 Torr (because hypoxia accentuates VA/Q mismatch on exercise). Cardiorespiratory variables and inert gas elimination patterns were measured at rest, during exercise, and between 2 and 30 min of recovery. Two profiles of VA/Q distribution behavior emerged during heavy exercise: in group 1 an increase in VA/Q mismatch (log SDQ of 0.35 +/- 0.02 at rest and 0.44 +/- 0.02 at exercise; P less than 0.05, n = 7) and in group 2 no change in VA/Q mismatch (n = 6). There were no differences in anthropometric data, work rate, O2 uptake, or ventilation during heavy exercise between groups. Group 1 demonstrated significantly greater VA/Q inequality, lower vital capacity, and higher forced expiratory flow at 25–75% of forced vital capacity for the first 20 min during recovery than group 2. Cardiac index was higher in group 1 both during heavy exercise and 4 and 6 min postexercise. However, both ventilation and cardiac output returned toward baseline values more rapidly than did VA/Q relationships. Arterial pH was lower in group 1 during exercise and recovery. We conclude that greater VA/Q inequality in group 1 and its persistence during recovery are consistent with the hypothesis that edema occurs and contributes to the increase in VA/Q inequality during exercise. This is supported by observation of greater blood flows and acidosis and, presumably therefore, higher pulmonary vascular pressures in such subjects.

Gravity effects on regional lung ventilation determined by functional EIT during parabolic flights

2001 ◽  
Vol 91 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Inéz Frerichs ◽  
Taras Dudykevych ◽  
José Hinz ◽  
Marc Bodenstein ◽  
Günter Hahn ◽  
...  
Keyword(s):  
Lung Volume ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Lung Ventilation ◽  
Tidal Breathing ◽  
Parabolic Flights ◽  
Regional Lung ◽  
Residual Capacity ◽  
The Right ◽  
Regional Lung Ventilation

Gravity-dependent changes of regional lung function were studied during normogravity, hypergravity, and microgravity induced by parabolic flights. Seven healthy subjects were followed in the right lateral and supine postures during tidal breathing, forced vital capacity, and slow expiratory vital capacity maneuvers. Regional 1) lung ventilation, 2) lung volumes, and 3) lung emptying behavior were studied in a transverse thoracic plane by functional electrical impedance tomography (EIT). The results showed gravity-dependent changes of regional lung ventilation parameters. A significant effect of gravity on regional functional residual capacity with a rapid lung volume redistribution during the gravity transition phases was established. The most homogeneous functional residual capacity distribution was found at microgravity. During vital capacity and forced vital capacity in the right lateral posture, the decrease in lung volume on expiration was larger in the right lung region at all gravity phases. During tidal breathing, the differences in ventilation magnitudes between the right and left lung regions were not significant in either posture or gravity phase. A significant nonlinearity of lung emptying was determined at normogravity and hypergravity. The pattern of lung emptying was homogeneous during microgravity.

Relationship between quasi-static pulmonary hysteresis and maximal airway narrowing in humans

1992 ◽  
Vol 72 (6) ◽  
pp. 2075-2080 ◽  
Author(s):  
V. Brusasco ◽  
R. Pellegrino ◽  
B. Violante ◽  
E. Crimi
Keyword(s):  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Transpulmonary Pressure ◽  
Forced Expiratory Volume ◽  
Maximal Response ◽  
Flow Volume ◽  
Airway Narrowing ◽  
Group 2 ◽  
Lung Periphery ◽  
Group 1

Two groups of subjects were studied: one with (group 1: 5 healthy and 4 mildly asthmatic subjects) and another without (group 2:9 moderately and severely asthmatic subjects) a plateau of response to methacholine (MCh). We determined the effect of deep inhalation by comparing expiratory flows at 40% of forced vital capacity from maximal and partial flow-volume curves (MEF40M/P) and the quasi-static transpulmonary pressure-volume (Ptp-V) area. In group 1, MEF40M/P increased from 1.58 +/- 0.23 (SE) at baseline up to a maximum of 3.91 +/- 0.69 after MCh when forced expiratory volume in 1 s (FEV1) was decreased on plateau by 24 +/- 2%. The plateau of FEV1 was always paralleled by a plateau of MEF40M/P. In group 2, MEF40 M/P increased from 1.58 +/- 0.10 at baseline up to a maximum of 3.48 +/- 0.26 after MCh when FEV1 was decreased by 31 +/- 3% and then decreased to 2.42 +/- 0.24 when FEV1 was decreased by 46 +/- 2%. Ptp-V area was similar in the two groups at baseline yet was increased by 122 +/- 9% in group 2 and unchanged in group 1 at MCh end point. These findings suggest that the increased maximal response to MCh in asthmatic subjects is associated with an involvement of the lung periphery.

Volume-pressure relationships of the thorax and lung in the newborn

1959 ◽  
Vol 14 (6) ◽  
pp. 909-913 ◽  
Author(s):  
Emilio Agostoni
Keyword(s):  
Tidal Volume ◽  
Functional Residual Capacity ◽  
Vital Capacity ◽  
Total Lung Capacity ◽  
Lung Capacity ◽  
Extended Range ◽  
Residual Capacity ◽  
Respiratory Apparatus ◽  
Retraction Force ◽  
Volume Range

The volume-pressure relationships of the respiratory apparatus have been studied in the dog fetus and in newborn and adult dogs. The mechanical changes produced when air first enters the lung have been described. In the newborn the lung-thorax compliance per unit vital capacity, taken over an extended range, is larger than in the adult: it is smaller, over the tidal volume range, during the first few days of life. The compliance of the thorax, particularly high at birth, decreases then progressively. The compliance of the lung after some days of life is similar to that of the adult. The relaxation volume and the functional residual capacity per total lung capacity increase significantly during growth. The lung retraction force, at relaxation volume, is smaller in the newborn than in the adult. Submitted on June 19, 1959

scholarly journals Effects of rapid saline infusion on lung mechanics and airway responsiveness in humans

2003 ◽  
Vol 95 (2) ◽  
pp. 728-734 ◽  
Author(s):  
Riccardo Pellegrino ◽  
Raffaele Dellacà ◽  
Peter T. Macklem ◽  
Andrea Aliverti ◽  
Stefania Bertini ◽  
...  
Keyword(s):  
Functional Residual Capacity ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Forced Expiratory Volume ◽  
Airway Responsiveness ◽  
Saline Infusion ◽  
Lung Mechanics ◽  
Elastic Recoil ◽  
Lung Volumes ◽  
Residual Capacity

Lung mechanics and airway responsiveness to methacholine (MCh) were studied in seven volunteers before and after a 20-min intravenous infusion of saline. Data were compared with those of a time point-matched control study. The following parameters were measured: 1-s forced expiratory volume, forced vital capacity, flows at 40% of control forced vital capacity on maximal (V̇m40) and partial (V̇p40) forced expiratory maneuvers, lung volumes, lung elastic recoil, lung resistance (Rl), dynamic elastance (Edyn), and within-breath resistance of respiratory system (Rrs). Rl and Edyn were measured during tidal breathing before and for 2 min after a deep inhalation and also at different lung volumes above and below functional residual capacity. Rrs was measured at functional residual capacity and at total lung capacity. Before MCh, saline infusion caused significant decrements of forced expiratory volume in 1 s, V̇m40, and V̇p40, but insignificantly affected lung volumes, elastic recoil, Rl, Edyn, and Rrs at any lung volume. Furthermore, saline infusion was associated with an increased response to MCh, which was not associated with significant changes in the ratio of V̇m40 to V̇p40. In conclusion, mild airflow obstruction and enhanced airway responsiveness were observed after saline, but this was not apparently due to altered elastic properties of the lung or inability of the airways to dilate with deep inhalation. It is speculated that it was likely the result of airway wall edema encroaching on the bronchial lumen.

Pulmonary effects of acute and chronic antigen exposure of immunized guinea pigs

1979 ◽  
Vol 46 (2) ◽  
pp. 346-353 ◽  
Author(s):  
P. D. Pare ◽  
M. C. Michoud ◽  
R. C. Boucher ◽  
J. C. Hogg
Keyword(s):  
Lung Volume ◽  
Guinea Pigs ◽  
Transpulmonary Pressure ◽  
Allergic Alveolitis ◽  
Histological Lesion ◽  
Acute Group ◽  
Before And After ◽  
Residual Capacity ◽  
Group 2 ◽  
Group 1

Subdivisions of lung volume and pressure-volume (PV) curves of the lung and chest wall were measured in guinea pigs immunized to ovalbumin before and after acute (group 1) and chronic (group 2) antigen exposure. The histopathology produced in chronically exposed animals was also assessed. Animals were anesthetized with pentobarbital sodium and studied in a pressure-sensitive body plethysmograph, using a fluid-filled esophageal catheter to measure transpulmonary pressure (PL). Functional residual capacity (FRC) was determined by the Boyle's law technique; total lung capacity (TLC) was defined as the lung volume at a PL of 30 cmH20, and residual volume (RV) was defined as the lung volume at a transrespiratory pressure of -50 cmH2O. Acute antigen challenge of group 1 animals resulted in a decrease in TLC (22%), and increases in FRC (20%) and RV (110%), suggesting combined bronchoconstriction and alveolar duct constriction. Chronic antigen exposure of group 2 animals resulted in minimal changes in subdivisions of lung volume and PV curves, and produced a histological lesion resembling allergic alveolitis rather than asthma.

scholarly journals Tidal volume single-breath washin of SF6 and CH4 in transient microgravity

2003 ◽  
Vol 94 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Brigitte Dutrieue ◽  
Manuel Paiva ◽  
Sylvia Verbanck ◽  
Marine Le Gouic ◽  
Chantal Darquenne ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Conformational Changes ◽  
Functional Residual Capacity ◽  
Vital Capacity ◽  
Time Dependent ◽  
Phase Iii ◽  
Lung Volumes ◽  
Single Breath ◽  
Residual Capacity ◽  
Slope Difference

We performed tidal volume single-breath washins (SBW) by using tracers of different diffusivity and varied the time spent in microgravity (μG) before the start of the tests to look for time-dependent effects. SF6 and CH4 phase III slopes decreased by 35 and 26%, respectively, in μG compared with 1 G ( P < 0.05), and the slope difference between gases disappeared. There was no effect of time in μG, suggesting that neither the hypergravity period preceding μG nor the time spent in μG affected gas mixing at volumes near functional residual capacity. In previous studies using SF6 and He (Lauzon A-M, Prisk GK, Elliott AR, Verbanck S, Paiva M, and West JB. J Appl Physiol 82: 859–865, 1997), the vital capacity SBW showed an increase in slope difference between gases in transient μG, the opposite of the decrease in sustained μG. In contrast, tidal volume SBW showed a decrease in slope difference in both μG conditions. Because it is only the behavior of the more diffusive gas that differed between maneuvers and μG conditions, we speculate that, in the previous vital capacity SBW, the hypergravity period preceding the test in transient μG provoked conformational changes at low lung volumes near the acinar entrance.

Dynamic mechanisms determine functional residual capacity in mice, Mus musculus

1979 ◽  
Vol 46 (5) ◽  
pp. 867-871 ◽  
Author(s):  
A. Vinegar ◽  
E. E. Sinnett ◽  
D. E. Leith
Keyword(s):  
Tidal Volume ◽  
Functional Residual Capacity ◽  
Flow Volume ◽  
Linear Portion ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Residual Capacity ◽  
Expiratory Flow ◽  
The Difference ◽  
Pentobarbital Sodium Anesthesia

Awake mice (22.6--32.6 g) were anesthetized intravenously during head-out body plethysmography. One minute after pentobarbital sodium anesthesia, tidal volume had fallen from 0.28 +/- 0.04 to 0.14 +/- 0.02 ml and frequency from 181 +/- 20 to 142 +/- 8. Functional residual capacity (FRC) decreased by 0.10 +/- 0.02 ml. Expiratory flow-volume curves were linear, highly repeatable, and submaximal over substantial portions of expiration in awake and anesthetized mice; and expiration was interrupted at substantial flows that abruptly fell to and crossed zero as inspiration interrupted relaxed expiration. FRC is maintained at a higher level in awake mice due to a higher tidal volume and frequency coupled with expiratory braking (persistent inspiratory muscle activity or increased glottal resistance). In anesthetized mice, the absence of braking, coupled with reductions in tidal volume and frequency and a prolonged expiratory period, leads to FRCs that approach relaxation volume (Vr). An equation in derived to express the difference between FRC and Vr in terms of the portion of tidal volume expired without braking, the slope of the linear portion of the expiratory flow-volume curve expressed as V/V, the time fraction of one respiratory cycle spent in unbraked expiration, and respiratory frequency.

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.

Sign in / Sign up

Export Citation Format

Share Document