Biomaterial Database

Methacholine-induced volume dependence of respiratory resistance in preschool children. 1999

F Marchal, and N Loos, and P Monin, and R Peslin

Laboratoire d'Explorations Fonctionnelles Pédiatriques, Service de Médecine Infantile 1, Hôpital d'Enfants Unité 14 INSERM de Physiopathologie Respiratoire, Vandoeuvre lès Nancy, France.

Enhanced negative volume dependence of airway resistance is associated with bronchoconstriction in tracheostomized paralysed open-chest animals. Significant upper airways responses may be associated with bronchoconstriction and could thereby alter the pattern of volume dependence in spontaneously breathing subjects. The aim of the study was to test whether volume dependence of respiratory resistance (Rrs) could be demonstrated in preschool children undergoing routine methacholine challenge. The volume dependence of respiratory oscillation resistance at 12 and 20 Hz (Rrs,12 and Rrs,20) was examined in eight 4-5.5-yr-old children showing a positive response to methacholine. Multiple linear regression analysis was also used to account for flow dependence during tidal breathing (Rrs,12 or Rrs,20=K1+K2¿V'¿+K3V). Rrs,12 and Rrs,20 yielded similar results. Negative volume dependence was present at baseline and significantly enhanced by methacholine (p<0.01). For instance, the mean+/-SD inspiratory K3 at 20 Hz was 4.1+/-1.3 hPa x s x L(-2) at baseline and -15.0+/-4.3 hPa x s x L(-2) after methacholine, in which case it was also larger on expiration than on inspiration (p<0.05), possibly as a result of upper airway responses. A significant increase in the negative volume dependence of respiratory resistance may thus be shown in preschool children in response to methacholine. The volume dependence (K3) during inspiration may be particularly useful in detecting bronchoconstriction, because it is less likely to be affected by upper airway mechanisms than during expiration.

UI	MeSH Term	Description	Entries
D008176	Lung Volume Measurements	Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.	Lung Capacities,Lung Volumes,Capacity, Lung,Lung Capacity,Lung Volume,Lung Volume Measurement,Measurement, Lung Volume,Volume, Lung
D008297	Male		Males
D001985	Bronchial Provocation Tests	Tests involving inhalation of allergens (nebulized or in dust form), nebulized pharmacologically active solutions (e.g., histamine, methacholine), or control solutions, followed by assessment of respiratory function. These tests are used in the diagnosis of asthma.	Allergen Bronchial Provocation Tests,Allergen Challenge, Endobronchial,Antigen Bronchial Provocation Tests,Bronchial Allergen Challenge,Bronchial Challenge Tests,Inhalation Provocation Tests,Provocation Tests, Bronchial,Endobronchial Challenge Tests,Allergen Challenge, Bronchial,Allergen Challenges, Bronchial,Allergen Challenges, Endobronchial,Bronchial Allergen Challenges,Bronchial Challenge Test,Bronchial Provocation Test,Challenge Test, Bronchial,Challenge Test, Endobronchial,Challenge Tests, Bronchial,Challenge Tests, Endobronchial,Challenge, Bronchial Allergen,Challenge, Endobronchial Allergen,Challenges, Bronchial Allergen,Challenges, Endobronchial Allergen,Endobronchial Allergen Challenge,Endobronchial Allergen Challenges,Endobronchial Challenge Test,Inhalation Provocation Test,Provocation Test, Bronchial,Provocation Test, Inhalation,Provocation Tests, Inhalation,Test, Bronchial Challenge,Test, Bronchial Provocation,Test, Endobronchial Challenge,Test, Inhalation Provocation,Tests, Bronchial Challenge,Tests, Bronchial Provocation,Tests, Endobronchial Challenge,Tests, Inhalation Provocation
D002675	Child, Preschool	A child between the ages of 2 and 5.	Children, Preschool,Preschool Child,Preschool Children
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000336	Aerosols	Colloids with a gaseous dispersing phase and either liquid (fog) or solid (smoke) dispersed phase; used in fumigation or in inhalation therapy; may contain propellant agents.	Aerosol
D000403	Airway Resistance	Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.	Airway Resistances,Resistance, Airway,Resistances, Airway
D015656	Respiratory Mechanics	The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.	Breathing Mechanics,Breathing Mechanic,Mechanic, Breathing,Mechanic, Respiratory,Mechanics, Breathing,Mechanics, Respiratory,Respiratory Mechanic
D016014	Linear Models	Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.	Linear Regression,Log-Linear Models,Models, Linear,Linear Model,Linear Regressions,Log Linear Models,Log-Linear Model,Model, Linear,Model, Log-Linear,Models, Log-Linear,Regression, Linear,Regressions, Linear