EVALUATION OF MIST TENT THERAPY IN CYSTIC FIBROSIS USING MAXIMUM EXPIRATORY FLOW VOLUME CURVE

PEDIATRICS ◽  
1972 ◽  
Vol 50 (2) ◽  
pp. 299-306
Author(s):  
E. K. Motoyama ◽  
L. E. Gibson ◽  
C. J. Zigas
Keyword(s):  
Cystic Fibrosis ◽  
Initial Period ◽  
Forced Expiratory Volume ◽  
Lower Airway ◽  
Flow Volume ◽  
Ventilatory Function ◽  
Volume Curve ◽  
Maximum Expiratory Flow ◽  
Expiratory Flow ◽  
Lower Airway Obstruction

The effect of home mist tent therapy in cystic fibrosis was reexamined using the measurement of maximum expiratory flow volume (MEFV) curves, forced expiratory volume (FEV1), and vital capacity (VC) in 16 patients every 2 weeks during a period of 4 to 5 months. In half of the patients the studies were made during an initial period of 8 to 12 weeks off and then a similar period on nocturnal mist tent therapy; in the other half the test conditions were reversed. No evidence of improvement in ventilatory function was found in these patients during the use of a mist tent; instead there was a small but significant decline in their ventilatory function. Home visits were made and bacterial contamination of mist tent equipment was noted in more than two-thirds of the tents in spite of careful cleaning instructions to the parents. The MEFV curve was found to be a simple yet sensitive test of evaluating lower airway obstruction in cystic fibrosis.

Forced expirations and maximum expiratory flow-volume curves during sustained microgravity on SLS-1

1996 ◽  
Vol 81 (1) ◽  
pp. 33-43 ◽  
Author(s):  
A. R. Elliott ◽  
G. K. Prisk ◽  
H. J. Guy ◽  
J. M. Kosonen ◽  
J. B. West
Keyword(s):  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Forced Expiratory Volume ◽  
Slight Reduction ◽  
Flow Volume ◽  
Lung Volumes ◽  
Volume Curve ◽  
Supine Posture ◽  
Maximum Expiratory Flow ◽  
Expiratory Flow

Gravity is known to influence the mechanical behavior of the lung and chest wall. However, the effect of sustained microgravity (microG) on forced expirations has not previously been reported. Tests were carried out by four subjects in both the standing and supine postures during each of seven preflight and four postflight data-collection sessions and four times during the 9 days of microG exposure on Spacelab Life Sciences-1. Compared with preflight standing values, peak expiratory flow rate (PEFR) was significantly reduced by 12.5% on flight day 2 (FD2), 11.6% on FD4, and 5.0% on FD5 but returned to standing values by FD9. The supine posture caused a 9% reduction in PEFR. Forced vital capacity and forced expired volume in 1 s were slightly reduced (approximately 3-4%) on FD2 but returned to preflight standing values on FD4 and FD5, and by FD9 both values were slightly but significantly greater than standing values. Forced vital capacity and forced expiratory volume in 1 s were both reduced in the supine posture (approximately 8-10%). Forced expiratory flows at 50% and between 25 and 75% of vital capacity did not change during microG but were reduced in the supine posture. Analysis of the maximum expiratory flow-volume curve showed that microG caused no consistent change in the curve configuration when individual in-flight days were compared with preflight standing curves, although two subjects did show a slight reduction in flows at low lung volumes from FD2 to FD9. The interpretation of the lack of change in curve configuration must be made cautiously because the lung volumes varied from day to day in flight. Therefore, the flows at absolute lung volumes in microG and preflight standing are not being compared. The supine curves showed a subtle but consistent reduction in flows at low lung volumes. The mechanism responsible for the reduction in PEFR is not clear. It could be due to a lack of physical stabilization when performing the maneuver in the absence of gravity or a transient reduction in respiratory muscle strength.

scholarly journals Longitudinal Examination of the Shape of the Maximum Expiratory Flow‐Volume Curve in Young Adults Following SARS‐CoV‐2 Infection

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Jonathon Stickford ◽  
Marc Augenreich ◽  
Valesha Province ◽  
Nina Stute ◽  
Abigail Stickford ◽  
...  
Keyword(s):  
Young Adults ◽  
Flow Volume ◽  
Volume Curve ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve ◽  
Expiratory Flow ◽  
Longitudinal Examination

The Shape of the Maximum Expiratory Flow Volume Curve

CHEST Journal ◽  
1988 ◽  
Vol 94 (4) ◽  
pp. 799-806 ◽  
Author(s):  
Mary C. Kapp ◽  
E.Neil Schachter ◽  
Gerald J. Beck ◽  
Lucinda R. Maunder ◽  
Theodore J. Witek
Keyword(s):  
Flow Volume ◽  
Volume Curve ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve ◽  
Expiratory Flow

scholarly journals Re-evaluation of Mist Therapy in Children with Cystic Fibrosis Using Maximum Expiratory Flow-volume Curves

1970 ◽  
Vol 4 (5) ◽  
pp. 478-478
Author(s):  
Etsuro K Motoyama ◽  
Lewis E Gibson ◽  
Charlene J Zigas ◽  
Charles D Cook
Keyword(s):  
Cystic Fibrosis ◽  
Flow Volume ◽  
Maximum Expiratory Flow ◽  
Expiratory Flow

Maximum expiratory flow-volume curve: mathematical model and experimental results

1995 ◽  
Vol 17 (5) ◽  
pp. 332-336 ◽  
Author(s):  
S. Abboud ◽  
O. Barnea ◽  
A. Guber ◽  
N. Narkiss ◽  
I. Bruderman
Keyword(s):  
Mathematical Model ◽  
Experimental Results ◽  
Flow Volume ◽  
Volume Curve ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve ◽  
Expiratory Flow

AREA UNDER THE MAXIMUM EXPIRATORY FLOW-VOLUME CURVE: A MEASURE OF LUNG FUNCTION IN PRESCHOOL CHILDREN

CHEST Journal ◽  
2005 ◽  
Vol 128 (4) ◽  
pp. 187S
Author(s):  
Caroline Pesant ◽  
Miriam Santachi ◽  
Mario Geoffroy ◽  
Theophile Niyonsega ◽  
Mario E. Dumas ◽  
...  
Keyword(s):  
Preschool Children ◽  
Lung Function ◽  
Flow Volume ◽  
Volume Curve ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve ◽  
Expiratory Flow

Interdependence of regional expiratory flows limits alveolar pressure differences

1990 ◽  
Vol 69 (4) ◽  
pp. 1413-1418 ◽  
Author(s):  
G. P. Topulos ◽  
G. J. Nielan ◽  
G. M. Glass ◽  
J. J. Fredberg
Keyword(s):  
Strong Evidence ◽  
Transpulmonary Pressure ◽  
Flow Volume ◽  
Alveolar Pressure ◽  
Volume Curve ◽  
Regional Lung ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve ◽  
Expiratory Flow ◽  
Degree Of Heterogeneity

Wilson et al. (J. Appl. Physiol. 59:1924-28, 1985) have asserted that interdependence of regional expiratory flows could cause differences of interregional alveolar pressures to relax to time-independent limits during forced deflation. To test the hypothesis that such limiting differences do arise, we examined regional alveolar pressures during complete and partial maximally forced deflations of six excised canine lungs. Alveolar pressures were monitored using alveolar capsules on each of six lobes during forced deflations initiated at transpulmonary pressures of 30, 20, 15, and 10 cmH2O. In all lungs and in all maneuvers, interregional heterogeneity of alveolar pressure increased rapidly early in the deflation but much less so or not at all later in the deflation. When we compared complete with partial forced deflations, 16 of 24 maneuvers in six lungs showed clear evidence that as deflation progressed the degree of heterogeneity at isovolumic points became independent of the transpulmonary pressure from which the deflation was initiated. That is, alveolar pressures relaxed to limiting interregional differences that did not depend on time elapsed from the onset of the deflation. These data offer strong evidence of the existence of limiting differences. Such behavior implies that the sequence of regional emptying is controlled by a competition of opposing influences: nonuniformities of airway and parenchymal properties promoting nonuniformity of emptying vs. interdependence of regional expiratory flows promoting uniformity. As nonuniformity of regional pressures grows so do those factors that oppose that nonuniformity. These data underscore the insensitivity of maximum expiratory flow-volume curve configuration to the underlying inhomogeneous pattern of regional lung emptying.

Physiologic Differentiation of Upper and Lower Airway Obstruction

1977 ◽  
Vol 86 (5) ◽  
pp. 630-632 ◽  
Author(s):  
Frank F. Davidson ◽  
George W. Burke
Keyword(s):  
Airway Obstruction ◽  
Upper Airway ◽  
Lower Airway ◽  
Flow Volume ◽  
Initial Part ◽  
Maximal Flow ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Lower Airways ◽  
Lower Airway Obstruction

Usual lower airway obstruction and fixed upper airway obstruction can be differentiated physiologically by means of the flow-volume curve. Normally, maximal flow decreases nearly linearly as lung volume decreases during expiration. In lower airway obstruction, this decrease is greatest at the beginning of expiration resulting in a curve that is concave upward. In fixed obstruction (stenosis) flow is constant throughout the initial part of forced maximal expiration and throughout virtually all of inspiration. This results in a plateau or flat curve which is characteristic and different from the curve in obstruction of lower airways. Cases in which this differentiation is clinically important are discussed.

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