Factors Affecting Pulmonary Compliance and Airway Resistance

2002 ◽  
pp. 6-7
Author(s):  
Michael L. Bishop
Keyword(s):  
Airway Resistance ◽  
Factors Affecting ◽  
Pulmonary Compliance

Immediate respiratory response to sudden cooling of the skin

1965 ◽  
Vol 20 (1) ◽  
pp. 65-69 ◽  
Author(s):  
W. R. Keatinge ◽  
J. A. Nadel
Keyword(s):  
Airway Resistance ◽  
Respiratory Response ◽  
Large Area ◽  
Sensitive Areas ◽  
Pulmonary Compliance ◽  
Cold Receptors ◽  
Decerebrate Cats

Showers at 25 C and below increased ventilation in man and respiration often could not be controlled voluntarily during showers at near 0 C. The increase took place within seconds and was accompanied by an increase in arterial pO2. The response could be obtained from high decerebrate cats and is believed to be a reflex initiated by cold receptors in the skin and mediated at midbrain level. The chest and abdomen were the most sensitive areas in man, but chilling any large area on the trunk or limbs caused some increase in ventilation. Although the showers caused an inspiratory shift in respiration and a sensation of difficulty in breathing, they caused little increase in airway resistance and no decrease in pulmonary compliance. respiration; reflex; cold showers Submitted on May 15, 1964

Decreased Specific Airway Conductance in Infant Apnea

PEDIATRICS ◽  
1985 ◽  
Vol 76 (2) ◽  
pp. 232-235
Author(s):  
Lily C. Kao ◽  
Thomas G. Keens
Keyword(s):  
Airway Resistance ◽  
Respiratory Control ◽  
Pulmonary Mechanics ◽  
Quiet Breathing ◽  
Airway Narrowing ◽  
Pulmonary Compliance ◽  
Thoracic Gas Volume ◽  
Airway Tone ◽  
Gas Volume ◽  
Airway Conductance

A disorder of respiratory control is the suspected etiology in a majority of infants with apnea. Although neurologic control of breathing has been evaluated in infants surviving an apneic episode, pulmonary mechanics have not been previously measured. Pulmonary mechanics were measured during sleep in ten infants with apnea, aged 45.4 ± 1.4 (SE) weeks postconception, and 13 control infants, aged 42.0 ± 0.8 weeks postconception. Infant apnea patients were defined as those having at least one episode of cyanosis, limpness, and apnea requiring vigorous stimulation or resuscitation to restore normal breathing, and in whom no treatable etiology could be found. Thoracic gas volume, airway resistance, and specific airway conductance were measured in an infant body pressure plethysmograph during quiet breathing. Dynamic pulmonary compliance was measured in six infants using an esophageal balloon. Specific airway conductance was decreased in infants with apnea compared with control infants (P < .05). Thoracic gas volume, airway resistance, and dynamic pulmonary compliance values were comparable with those of control infants. These data suggest that airway narrowing or abnormal control of airway tone during sleep may contribute to apnea in some infants.

Effect of Isoproterenol Inhalation on Airway Resistance in Chronic Bronchopulmonary Dysplasia

PEDIATRICS ◽  
1984 ◽  
Vol 73 (4) ◽  
pp. 509-514
Author(s):  
Lily C. Kao ◽  
David Warburton ◽  
Arnold C. G. Platzker ◽  
Thomas G. Keens
Keyword(s):  
Mechanical Ventilation ◽  
Bronchopulmonary Dysplasia ◽  
Airway Resistance ◽  
Hyaline Membrane Disease ◽  
Pulmonary Mechanics ◽  
Quiet Breathing ◽  
Pulmonary Compliance ◽  
Thoracic Gas Volume ◽  
Gas Volume ◽  
Airway Conductance

The effects of isoproterenol inhalation on pulmonary mechanics in ten infants with bronchopulmonary dysplasia (BPD), aged 41 ± 1 (SE) weeks postconception, with gestational age at birth 30 ± 1 weeks, and birth weight 1,590 ± 200 g were studied. The infants had: (1) hyaline membrane disease requiring mechanical ventilation in the first five days of life, (2) mechanical ventilation and/or FIO2 greater than 30% for at least 30 days, and (3) stage III or IV radiographic changes. Thoracic gas volume, airway resistance, and specific airway conductance were measured in an infant body pressure plethysmograph during quiet breathing. Dynamic pulmonary compliance was measured using an esophageal balloon. These infants with BPD had greater airway resistance, lower specific airway conductance, and lower dynamic pulmonary compliance than 16 normal control infants (age 40 ± 1 weeks postconception). In the infants with BPD, measurements were obtained before and ½, 1, 2, and 6 hours after the administration of isoproterenol aerosol 0.1% inhalation or saline aerosol placebo, five breaths by slow inflation of the lungs with an anesthesia bag. Within 30 minutes after isoproterenol inhalation, airway resistance decreased 28% ± 5% and specific airway conductance increased 53% ± 15%. Thoracic gas volume and dynamic pulmonary compliance did not change. There were no changes following administration of the placebo. Isoproterenol inhalation is associated with rapid short-term improvement in airway resistance and specific airway conductance in infants with BPD.

Progress In The Practical Application Of Automated Image Analysis To Tem Negatives

1977 ◽  
Vol 35 ◽  
pp. 214-217
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly
Keyword(s):  
Image Analysis ◽  
Image Quality ◽  
Exposure Time ◽  
Image Contrast ◽  
Automated Image Analysis ◽  
Practical Application ◽  
Factors Affecting ◽  
High Image Quality ◽  
Qualitative Evidence ◽  
Comprehensive Study

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

Factors affecting microstructural scale in liquid crystalline polymers

1990 ◽  
Vol 48 (4) ◽  
pp. 220-221
Author(s):  
Christine M. Dannels ◽  
Christopher Viney
Keyword(s):  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Factors Affecting ◽  
Crystalline Polymers ◽  
Thermal Expansion Coefficients ◽  
Low Thermal Expansion ◽  
Lower Viscosity ◽  
Fine Microstructure ◽  
Planar Orientation ◽  
Strength And Stiffness

Processing polymers from the liquid crystalline state offers several advantages compared to processing from conventional fluids. These include: better axial strength and stiffness in fibers, better planar orientation in films, lower viscosity during processing, low solidification shrinkage of injection moldings (thermotropic processing), and low thermal expansion coefficients. However, the compressive strength of the solid is disappointing. Previous efforts to improve this property have focussed on synthesizing stiffer molecules. The effect of microstructural scale has been overlooked, even though its relevance to the mechanical and physical properties of more traditional materials is well established. By analogy with the behavior of metals and ceramics, one would expect a fine microstructure (i..e. a high density of orientational defects) to be desirable.Also, because much microstructural detail in liquid crystalline polymers occurs on a scale close to the wavelength of light, light is scattered on passing through these materials.

Factors affecting dentist participation in a state Medicaid program

1990 ◽  
Vol 54 (11) ◽  
pp. 638-643 ◽  
Author(s):  
PC Damiano ◽  
ER Brown ◽  
JD Johnson ◽  
JP Scheetz
Keyword(s):  
Medicaid Program ◽  
Factors Affecting

Speech Therapy Services in a Large School System: A Six-Year Overview

1976 ◽  
Vol 7 (4) ◽  
pp. 207-219 ◽  
Author(s):  
Constance P. DesRoches
Keyword(s):  
School System ◽  
Speech Therapy ◽  
Factors Affecting ◽  
Case Load ◽  
Number Of Children ◽  
School Population ◽  
System A ◽  
Therapy Services ◽  
And Shifts ◽  
Selection Factors

A statistical review provides analysis of four years of speech therapy services of a suburban school system which can be used for comparison with other school system programs. Included are data on the percentages of the school population enrolled in therapy, the categories of disabilities and the number of children in each category, the sex and grade-level distribution of those in therapy, and shifts in case-load selection. Factors affecting changes in case-load profiles are identified and discussed.

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